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For potato, diploid hybrid breeding is a novel breeding technique that speeds up the development of new varieties. A consequence of hybrid breeding is the introduction of hybrid true potato seeds as starting material. From these seeds, seedling tubers can be produced in one field season, to use as starting material for a seed or a ware crop in the following year. For breeding purposes as well as for seed crop and ware crop production, it is essential to produce seedling tubers of high quality. The production of seedling tubers is a new step in the potato production chain; therefore, we investigated the effect of tuber quality traits on plant development and yield. With similar seedling tuber weight, more eyes per seedling tuber led to more stems per plant. This was compensated by a lower number of tubers per stem resulting in an equal total tuber number and weight per plant at the end of the growing season. A higher seedling tuber weight led to a higher soil cover in the field. Hybrid potato plants grown from larger seedling tubers produced a greater total tuber weight per plant than plants grown from smaller tubers, while number of eyes and stems per tuber had no effect on final yield when using equal seedling tuber weight. [ABSTRACT FROM AUTHOR]

Water management plays an important role in crop-stress tolerance; however, its effect on the cold tolerance of rice seedlings is unclear. Therefore, we set four different water contents (25%, 45%, 65% and 85%) in the substrate with Liangyou 6326 as the experimental material to study the influence of different water contents on the cold tolerance of rice seedlings. The results showed that in the control temperature treatment, length and number of white roots, dry matter weight, stem base width and strong seedling index first increased and then decreased with decreasing water content, and the seedlings were more robust when the water content was 45%. In the cold treatment, the survival rate and strong seedling index first increased and then decreased with decreasing water content, and the cold tolerance of seedlings was the best when the water content was 45%. The mechanism of improving the cold tolerance is that moderate water deficit improved the antioxidant enzyme activity, reduced the content of malondialdehyde and improved root activity and leaf photosynthetic performance. Correlation analysis showed that the survival rate of seedlings was significantly positively correlated with root activity, antioxidant enzyme activity and seedling quality in the control temperature and cold treatment. The above results showed that soil water played an important role in regulating the cold tolerance of rice. Reasonable water management could not only cultivate high-quality seedlings but also improve the cold tolerance of rice seedlings, helping to guarantee high and stable rice yields. [ABSTRACT FROM AUTHOR]

Watermelon Jing xin No.4 and pumpkin Jingxinzhen No.4 were used as test materials, and LED pure white light was taken as control (CK). Five treatments were set, namely, red-blue light alternating at 1 hour interval (R/B1), red-blue mixed light (RB), red-blue light alternating at 6 hours interval (R/B6), pure blue light (B) and pure red light (R). Besides, experiments were carried out in a fully artificial light plant to delve into the optimal light formula for the growth and development of watermelon and Pumpkin seedlings. The results showed as follows: (1) the absolute growth rate of plant height, stem diameter and leaf area of watermelon seedlings under R/B6 treatment were increased by 77.2%, 110.7% and 68.5% compared with the control, respectively; the number of leaves of watermelon seedlings under R/B1 treatment was significantly increased by 78.6% compared with the control at 40d (P<0.05). Under R/B1 treatment, the absolute growth rate of pumpkin seedling height and the number of leaves at 40d after planting were significantly increased by 211% and 18% (P<0.05), respectively, and the absolute growth rate of stem diameter was increased by 85%. (2) The crude polysaccharide content of watermelon and pumpkin seedlings under R treatment was increased by 25.5% and 13.4% compared with the control (P<0.05), and the crude protein content of watermelon seedlings under B treatment was increased by 9.4% compared with the control, and the chlorophyll content of watermelon and pumpkin seedlings under RB treatment was higher than that under the control 10 to 40 days after planting. Watermelon and pumpkin seedlings treated with RB showed a 1.8% and 0.3% increase in chlorophyll content, respectively, on the 40th day after planting, compared to control plants. (3) At 40th day after implantation, PIabs of watermelon seedlings under B and R/B6 treatments were 2.8 times and 1.1 times higher than that of control, respectively. Pumpkin seedlings treated with R/B1 and R/B6 had 110% times and 34% higher PIabs, respectively, than control seedlings. In summary, alternating irradiation of watermelon and pumpkin seedlings with red and blue light effectively improved the growth and development of watermelon and pumpkin seedlings and enhanced the chlorophyll fluorescence performance, while blue light can increased the crude protein content and red light can increase the crude polysaccharide content. Thus, when watermelon and pumpkin seedlings are cultured in a uniform manner, alternating red and blue light can maximize the seedling quality and provide high-quality seedlings for factory production [ABSTRACT FROM AUTHOR]

Eucheumatoid seaweeds, encompassing the genera Kappaphycus and Eucheuma, are widely cultivated globally, particularly in tropical regions. However, ice-ice disease (IID) poses a significant challenge to their production, causing substantial economic losses. This study aimed to elucidate the factors contributing to IID in eucheumatoid seaweeds, focusing on the perspectives of seaweed farmers in Sibutu, Tawi-Tawi, Philippines. A mixed methods approach was employed, utilizing both one-to-one interviews (n = 96) and focus group discussions. The majority of the interviewed farmers were male, aged between 31 and 60 years, with extensive experience (11‒25 years) in seaweed cultivation. Notably, all participants possessed a familiarity with IID since childhood. Farmers described IID as a pathological condition affecting eucheumatoid seaweeds, characterized by the emergence of white and soft areas on the seaweed thalli. The initial stages of the disease manifest as a pale discolouration of the thalli and the presence of epiphytes or debris. Several environmental factors were identified by the farmers as contributing to IID incidence, including high or low water temperatures, low salinity (particularly after heavy rainfall), stagnant water currents, nutrient deficiencies, inadequate seedling quality, and poor farm management practices. Additionally, deepwater (nearshore) farms were reported to be more susceptible to IID. Farmers noted that easterly winds could exacerbate the disease by facilitating the infestation of epiphytes on the seaweed. Furthermore, the prevalence of IID was observed to be highest during the dry and hot season. Kappaphycus striatus was identified by the farmers as being more susceptible to IID compared with K. alvarezii and Eucheuma denticulatum. The negative impact of IID on farmers' livelihoods was also highlighted. Some mitigation strategies employed by the farmers included the application of inorganic nutrient enrichments (e.g. ammonium phosphate (16–20-0, N-P-K) and complete (14–14-14, N-P-K) fertilizers), frequent relocation of infected seaweed to different farms, and the cultivation of more IID-resistant species. Highlights: Farmers defined ice-ice disease as an anomaly in eucheumatoid seaweeds that showed white and soft thalli. Ice-ice disease is linked to unfavourable water parameters, nutrient deficiencies and poor seedling quality and management. Kappaphycus striatus is more prone to ice-ice disease than K. alvarezii and Eucheuma denticulatum. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The seedling stage is crucial for plant establishment in natural and agricultural ecosystems. Some species have reduced germination rates and are sensitive to environmental stresses, making this stage even more critical. In this study, we employed sublethal stress levels in seeds to enhance germination responses and increase survival of seedlings susceptible to water deficiency. Hydration and dehydration cycles in seeds were applied to investigate their effects on germination parameters and subsequent seedling performance under water deficit conditions. The time of hydration and dehydration was based on triphasic imbibition and drying curves and applied up to three times prior germination. Results revealed increased germination rate (%G) and decreased time to reach 50% germination (T50) after hydration and dehydration cycles. Additionally, cyclically treated seeds produced seedlings with a higher survival rate under water deficit, faster growth rates, and greater dry matter production. The Dickson quality index and drought tolerance indices improved, while the stress susceptibility index decreased. These findings indicate that hydration and dehydration cycles in the seeds induce changes in the seedlings, modifying their basal stress response levels and contributing to the production of hardier seedlings capable of coping with environmental stresses. These responses are anchored in plant stress memory acquired after sublethal exposure to stress levels. [ABSTRACT FROM AUTHOR]

Mining activities significantly contribute to environmental pollution by releasing chemical contaminants into ecosystems, making natural recovery challenging. In this study, we amended the mining tailings from the Fundão dam with reference soil to simulate the heterogeneity of tailings concentrations to which native species are exposed. We aimed to identify the tailings concentration that best supports the development of two native species, Deguelia costata and Peltophorum dubium. Our results showed that substrates with lower concentration of tailings had an increase in organic matter content and higher acidity. In contrast, substrates with higher tailings concentration showed increased levels of toxic metals; yet these metals seemed not to be readily available to plants, as evidenced by the enhanced biomass accumulation and improved seedling quality in these subtracts. Conversely, the reference soil, being nutritionally deficient and acidic, may have led to increased absorption of toxic metals by the plants. This resulted in reduced growth and increased activity of antioxidant enzymes and synthesis of flavonoids. Both species selectively accumulated iron in the roots and manganese in the leaves, without reaching phytotoxic levels. The findings unequivocally demonstrate that D. costata and P. dubium exhibited remarkable resilience by successfully thriving and growing in highly contaminated substrates (up to 100% mining tailings). Hence, both D. costata and P. dubium prove to be highly suitable candidates for the restoration of areas devastated by iron mining activities. [ABSTRACT FROM AUTHOR]

(1) Tree peony (Paeonia suffruticosa Andrews) is a woody ornamental plant originating from China, and beloved by people worldwide. Non-structural carbohydrates (NSCs) play a crucial role in regulating the flowering quality of tree peonies in both field and potted conditions. However, the effects of NSCs accumulation and allocation in various organs during the vegetative growth stage on the flowering quality of tree peony under forcing culture remains unclear. (2) Two-year-old grafted seedlings of tree peony cv. 'Luoyanghong' were subjected to orthogonal treatments to investigate the role of NSCs accumulation in plants' developmental process. We measured leaf photosynthetic capacity, NSCs accumulation in the organs of seedlings, observed key ornamental characteristics of flowering quality under forcing culture conditions, and evaluated the qualities of seedlings and flowers using the seedling index (SI) and flowering index (FI), respectively. (3) There was a significant positive correlation between leaf photosynthetic capacity and NSCs accumulation in both the whole plant and roots of potted tree peony. Roots were identified as the primary organs for NSCs accumulation in potted tree peonies. Sufficient NSCs accumulation in the plant, particularly in the roots during the defoliation period, was essential not only for enhancing the seedling quality of potted tree peonies but also for improving the flowering quality under forcing culture conditions. Both the seedling index (SI) and flowering index (FI) exhibited a significant dose-response with increasing root NSCs accumulation at defoliation. The T3 group, which involved slight root pruning (by 25%), combined with a high-concentration rooting agent (750 mg·L−1) and Metarhizium anisopliae (20 million U·mL−1), resulted in the highest photosynthetic capacity, SI, FI and NSCs accumulation status (NSCAR), making it the optimal treatment combination. (4) This finding indicates that increasing NSCs accumulation in the roots of potted tree peonies is a crucial biological foundation for producing high-quality potted flowers under forcing culture conditions, which provide new insights into the importance of NSCs in tree peony flowering and may improve the production technology for high-quality potted tree peony flowers under forcing culture conditions. [ABSTRACT FROM AUTHOR]

The uniformity of growth and mechanical properties of grafted seedlings affect the quality of mechanical grafting operations. The growth uniformity of grafted seedlings in a greenhouse will be poor due to the uneven and unstable light and temperature conditions. Plant factories can cultivate grafted seedlings in the most suitable environment by regulating environmental parameters such as light and temperature. The aim of this study was to investigate the impact of the light conditions on tomato seedlings in plant factory and to develop an optimal cultivation light formula. The effects of light intensity (50, 100, 150, 200, and 250 μmol m−2 s−2) and photoperiod (10, 12, 14, 16, and 18 h a day(h/d)) on the morphological and mechanical properties of tomato seedlings were experimentally investigated. Orthogonal experiments were conducted involving light quality (R:B = 75:25, R:B = 50:50, and R:B = 25:75), light intensity (150 μmol m−2 s−2, 200 μmol m−2 s−2, and 250 μmol m−2 s−2), and photoperiod (14, 16, and 18 h/d) as independent variables to determine the optimal combination. Finally, a comparative grafting experiment was conducted between the seedlings cultivated using the optimal light formula and commercially available seedlings. The result showed that increasing light intensity inhibited hypocotyl length and promoted seedling stem growth, and excessive light intensity decreased seedling mechanical properties. The optimal light intensity for rootstocks is 200 μmol m−2 s−2, and the optimal light intensity for scions is 250 μmol m−2 s−2. Shortening the photoperiod would promote hypocotyl growth and inhibit seedling stem elongation. Different photoperiods had a significant impact on the mechanical properties of tomato seedlings. The most suitable photoperiod for rootstocks was 18 h/d and for scions was 16 h/d. The most suitable light formula was R:B = 50:50, 250 μmol m−2 s−2, 18 h/d. By analyzing the experimental results, the mechanical properties of seedlings grown by the regulated light environment were better than those of commercially available seedlings, and the success rate of mechanical grafting was 7% higher. Overall, in plant factories compared to commercially available tomato seedlings, tomato seedlings cultivated by the regulated light environment were more suitable for mechanical grafting. This research result provides theoretical support for subsequent research on grafting machinery. [ABSTRACT FROM AUTHOR]

Melon damping off, which has a negative impact on melon quality and yield, can be safely and effectively managed with Trichoderma. Melon cultivar 'Longtian No. 1' was evaluated at both the adult and seedling stages in a pot experiment. The Rs and PD liquids were utilized as CK1 and CK2, respectively. Trichoderma viride Tv286 treatments T1B, T2B, T3B, and T4B were used based on Rs at concentrations of 104, 105, 106, and 107 CFU·g−1, respectively. The impact of several treatments on the antioxidant system and seedling quality of melon were assessed at 15, 25, and 35 days after sowing. We examined the effects of several treatments on melon quality, yield attributes, and physiological and biochemical markers during the adult stage at 10, 20, and 30 days after pollination. The effects of several treatments on melon damping off were also studied. Applying T. viride Tv286 at different rates effectively increased the activities of enzymes, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), and polyphenol oxidase (PPO), in the leaves of melon seedlings, significantly reduced the malondialdehyde (MDA) content, and improved the root–shoot ratio and seedling strength index. In terms of its influence on promoting the effect of antioxidant system indicators, T3B performed well. Melon seedlings treated with T3B showed higher CAT, POD, SOD, APX, and PPO activities in their leaves 35 days after sowing compared to CK1 (189.74, 169.61, 175.36, 224.20, and 477.39%, respectively). The strong seedling index and root–shoot ratio showed improvements of 130.43 and 79.71%, respectively, and the MDA content dropped by 35.66% at 35 days after sowing compared to CK1. Varying the rates at which T. viride Tv286 was applied increased the nitrate reductase (NR) activity and nitrate nitrogen, proline (Pro), chlorophyll, soluble sugar, and soluble protein contents in mature melon leaves, increasing melon quality and yield. T3B is the most effective marketing campaign. Compared to CK1, mature T3B leaves had higher NR activity, nitrate nitrogen content, chlorophyll content, soluble sugar content, soluble protein content, and Pro content 30 days after melon pollination (100.40, 135.17, 68.59, 93.65, 158.13, and 238.67%, respectively). The soluble solids, soluble protein, soluble sugar, vitamin C contents, and yield of melon fruit increased by 50.07, 126.82, 60.62, 70.79, and 61.45%, respectively, at 30 days after melon pollination compared to CK1. Optimal management of melon damping off can be accomplished with the application of T. viride Tv286 at different concentrations, with T3B exhibiting the best effect. The control effects reached 90.48 and 72.99% at the seedling and adult stages, respectively. Overall, T. viride Tv286 improved seedling quality, damping off control efficacy, melon yield and quality, and the antioxidant system during the seedling stage and enhanced physiological and biochemical characteristics during the adult stage. This study indicates the potential of T. viride Tv286 conidia as a biological control agent because it can prevent plant disease, increase yield, and improve quality. [ABSTRACT FROM AUTHOR]

The concentration of nitrogen fertilizer is matched with the nutrient requirements in different growth stages of plants, which coordinates their vegetative and reproductive growth. In this study, the influences of nitrogen concentration before and after initiation of flower bud differentiation (first and second stage, respectively) on pepper seedling quality were studied. The chlorophyll a content, sucrose synthase activity, and sucrose phosphate synthase activity of pepper seedlings grown under moderate nitrogen (15 mmol L−1) in the first stage combined with high nitrogen (25.61 mmol L−1) in the second stage were 15.7%, 39.3%, and 34.6% higher than those of the same nitrogen concentration (15 mmol L−1) in the first and second stages treatment, respectively. The regression model also showed that the values of flower bud diameter, shoot fresh weight, root fresh weight, and glutamine synthetase activity of pepper were high under the condition of moderate nitrogen in the first stage and higher nitrogen in the second stage. In addition, the results of comprehensive evaluation showed that moderate nitrogen (15 mmol L−1) in the first stage and high nitrogen (25.61 mmol L−1) in the second stage treatment ranked first, which improved carbon and nitrogen metabolism, increased biomass accumulation, and promoted the flower bud differentiation and flowering of pepper seedlings. [ABSTRACT FROM AUTHOR]

Assessing the quality of maize seedlings is crucial for field management and germplasm evaluation. Traditional methods for evaluating seedling quality mainly rely on manual field surveys, which are not only inefficient but also highly subjective, while large-scale satellite detection often lacks sufficient accuracy. To address these issues, this study proposes an innovative approach that combines the YOLO v8 object detection algorithm with Voronoi spatial analysis to rapidly evaluate maize seedling quality based on high-resolution drone imagery. The YOLO v8 model provides the maize coordinates, which are then used for Voronoi segmentation of the field after applying the Convex Hull difference method. From the generated Voronoi diagram, three key indicators are extracted: Voronoi Polygon Uniformity Index (VPUI), missing seedling rate, and repeated seedling rate to comprehensively evaluate maize seedling quality. The results show that this method effectively extracts the VPUI, missing seedling rate, and repeated seedling rate of maize in the target area. Compared to the traditional plant spacing variation coefficient, VPUI performs better in representing seedling uniformity. Additionally, the R2 for the estimated missing seedling rate and replanting rate based on the Voronoi method were 0.773 and 0.940, respectively. Compared to using the plant spacing method, the R2 increased by 0.09 and 0.544, respectively. The maize seedling quality evaluation method proposed in this study provides technical support for precision maize planting management and is of great significance for improving agricultural production efficiency and reducing labor costs. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The yellow (Passiflora edulis) and sweet (Passiflora alata) passion fruit plants hold significant economic importance in tropical fruit cultivation, valued not only for the quality of their fruit but also for their medicinal properties. Conventional propagation through seeds faces challenges due to irregular and slow germination, affecting the time required for seedling formation and the viability and uniformity of plantations. The use of plant growth regulators has been explored as a strategy to overcome these barriers, improving both the rate and uniformity of seed germination. This study aimed to evaluate the influence of seed imbibition with plant growth regulators on the germination and subsequent growth of yellow and sweet passion fruit seedlings. Gibberellic acid (GA3) and GA4+7 combined with 6-benzyladenine (GA4+7+6BA) were applied in five different concentrations (0, 250, 500, 750, and 1000 mg L−1 a.i.). The experiments were conducted in both laboratory and greenhouse conditions, following a completely randomized design with a 2 × 5 factorial scheme. The varieties tested were 'BRS Mel do Cerrado' for sweet passion fruit and 'IAC-275' for yellow passion fruit. Quantitative parameters, such as germination percentage, germination speed index, fresh and dry biomass of roots and shoots, and enzymatic activity, were assessed. The results indicated that GA3, at higher concentrations, significantly enhanced both germination percentage and speed index in both Passiflora alata and Passiflora edulis when compared to the control. Additionally, seedlings treated with GA3 showed a marked increase in shoot and root biomass, particularly at concentrations of 500 and 750 mg L−1. Enzymatic assays revealed heightened catalase and peroxidase activities in treated seedlings, indicating improved stress tolerance. In contrast, the GA4+7+6BA treatment showed less pronounced effects on seedling growth. Overall, GA3 was more effective in enhancing germination and seedling growth in both species, suggesting its potential application in improving the propagation of passion fruit. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is one of the most important cereal crops in the world. Bakanae disease is a significant rice disease widely distributed in rice-growing regions worldwide. Therefore, the present investigation aimed to assess the optimal concentrations of paclobutrazol (PBZ) as a treatment for rice grains (cv. Sakha 108) to control bakanae disease, also evaluating its impact on grain germination, seedling growth parameters as well as disease index. Paclobutrazol concentrations had no significant impact on seed germination, regardless of whether the seeds were incubated with Fusarium fujikuroi or not. Application of PBZ, either alone or in combination with fungal pathogens, negatively impacted the rice seedlings' height. Paclobutrazol at 25, 50 and 100 mg/L, combined with the fungal pathogen positively impacted root length. Paclobutrazol at 3 and 6 mg/L mitigated the adverse impact on chlorophyll pigments content in infected seedlings. The highest proline contents were achieved by 100 mg/L PBZ alone or in combination with fungal pathogens. It has been observed that the application of PBZ, either alone or in combination with a fungal pathogen, leads to the enhancement of catalase, peroxidase, and polyphenol oxidase activities. The median lethal concentration of PBZ was 0.874 mg/L; applying low concentrations of paclobutrazol effectively increased the percentage of fungal growth suppression. Application of PBZ, at higher concentrations (50 and 100 mg/L), decreased infection percentage and disease severity index (DSI) significantly. These findings suggest that PBZ can be an effective treatment for controlling bakanae disease and enhancing resistance in rice plants. [ABSTRACT FROM AUTHOR]

This study determined the optimal ultraviolet (UV)-B dose of major vegetable seedlings in a plant factory with artificial light for labor saving. Four vegetable seedlings, cucumber, watermelon, tomato, and pepper, were used as test crops. UV-B irradiation was conducted at four different UV-B doses of 1.08, 2.16, 3.24, and 4.32 kJ·m−2 d−1 for 3 h a day for 3 days after graft-take and temporary planting of fruit vegetable seedlings. After UV-B irradiation, seedlings were moved to a greenhouse and exposed to ultraviolet rays of sunlight; growth was observed; and chlorophyll fluorescence was measured. When subjected to UV-B irradiation, minimal changes in external traits of fruit vegetable seedlings were observed at doses below 2.16 kJ·m−2·d−1, while at higher intensities, issues such as chlorosis emerged. When UV-B was irradiated at 4.32 kJ·m−2·d−1, cucumber exhibited a decrease in hypocotyl length by 6.4 cm, and watermelon by 1.7 cm compared with the control. Additionally, cucumber and watermelon both showed a decrease in leaf area by 75.6 cm2 and 49.8 cm2, respectively, indicating a tendency of growth inhibition. For tomatoes and peppers, when UV-B was irradiated at 1.08 kJ·m−2·d−1, they exhibited an improvement in compactness by 5 and 2.5 mg·cm−1, respectively, compared with the control. Chlorophyll fluorescence parameters indicated a positive correlation between ABS/RC and DIO/RC with increasing UV-B doses, while FV/FM and PIABS showed a negative correlation. Using UV-B during the seedling acclimation period, seedlings can adapt to external UV radiation, thereby suppressing excessive growth and promoting the production of robust seedlings. Moreover, the utilization of UV-B within a plant factory allows for conducting the acclimation process within the facility, reducing the need for seedlings to be transported to conventional nurseries and offering potential benefits in terms of operational efficiency. [ABSTRACT FROM AUTHOR]

Mechanical transplanting has become an important part of modern Chinese rice production, and an inadequate sowing rate severely inhibits rice seedling growth and development. Precision drill sowing is an effective method for obtaining higher quality seedlings during machine transplanting. There is a lack of systematic research on the precision drilling of rice. Therefore, we carried out research on the quality of machine-transplanted seedlings and precision drill sowing transplantation. A greenhouse experiment (Liaoning Rice Research Institute) and field experiment (Sujiatun District, Shenyang City, Liaoning Province, China) were conducted between 2020 and 2021 to analyze the influence of precision drill sowing on rice growth and yield. Precision drill sowing was conducted at four sowing rates (3400, 3600, 3800, and 4000 seeds/tray), and traditional broadcasting was also conducted at a sowing rate of 4000 seeds/tray. We evaluated the seedling rice quality, physiological and biochemical characteristics and transplanting quantity. The results indicated that precision drill sowing at a sowing rate of 3400 seeds/tray resulted in the highest plumpness value (0.18) and seedling strength index (0.42) of individual plants. However, the empty hill rate was as high as 3.05%, which did not satisfy the field seedling number requirement. Precision drill sowing at a sowing rate of 4000 seeds/tray resulted in the lowest physiological (the average levels of SOD, POD and soluble protein were 311.78 µg/g, 8.25 µg/g and 1.28 µg/g) and biochemical indices of individual plants. The damaged seedling rate increased by 2.07%, and the dead seedling rate increased by 0.25%, resulting in poor seedling and transplanting quality. In this study, 3800 seeds/tray was the best option and had the highest yields of 10,776.60 kg/ha and 10,730.85 kg/ha over the two years. This sowing approach performs well in terms of field transplanting, provides a balance point between seedling number and quality and is conducive to rice yield production. The results of this study are important for improving rice seedling quality, enhancing field transplanting quantity and increasing rice yield and food security. [ABSTRACT FROM AUTHOR]

The structure of the root system of the conilon coffee tree has improved over the years through propagation, genetic, and agronomic studies in response to demands for improvements in plant development, production, and survival of the species. Scientific research plays an important role in generating technologies and the security of applications. However, there is a need to refine the content generated to analyze discoveries and trends on the subject. Therefore, the present study conduct a bibliometric review and analysis on the main contributions of relevant studies, researchers, organizations, and countries in academic research on the rooting of Coffea canephora in the Web of Science (WOS) database. Data from the WOS database published between 1982 and 2021 and systematized in the VOSviewer software showed a set of 92 articles, the majority of which originated in Brazil and France, with the main groups being the Brazilian Agricultural Research Corporation, the Federal University of Viçosa, and CIRAD. The study was divided into five areas: genetic diversity, asexual propagation, nematology, tolerance to water stress, and micropropagation. However, in the context of climate changes and its impact on the production and longevity of Brazilian coffee farming, research focused on the root system has increased significantly, integrating it into lines that explore and integrate topics such as climate risk, water management, drought tolerance, and drip irrigation, including reflections on the performance of coffee agronomy. [ABSTRACT FROM AUTHOR]

Indicators for predicting the quality and vigor of fruit tree seedlings can be worthwhile if they are conveniently and visually assessable in various climatic regions. Since allometric relationships exist between plum seedling vigor index and morphological traits, this study evaluated morphological features in plum seedlings while determining their quality and vigor. The samples were of major commercial varieties from several regions of Iran, and the assessments followed path analysis and multiple linear regression. Plum seedlings of 8 commercial cultivars were harvested in three replicates from 11 nurseries in four provinces. Morphological indicators included seedling height, diameter above the graft line (DAGL) and at root-collar (RCD), root length, number of roots and branches, seedling vigor, dry weights of aerial parts and roots (ADW and RDW, respectively), and ratio of height to DAGL and seedling height to ADW. Simple correlations among these variables appeared diverse, and the correlation coefficients broke down into direct and indirect effects through path analysis, with vigor as the dependent variable. This variable increased with some of its components, including DAGL and dry weight. However, the ratio of height to DAGL decreased when the accumulated growing degree-days (AGDD) increased from 2700 to about 4500 °C per day in the various regions. Average vigor values of certified and uncertified seedlings were 11.7 and 19.2, respectively. Among the visually assessable traits in the nursery, DAGL showed a higher correlation with the vigor variable and other morphological features, thus making it the most important index for plum seedling evaluation. [ABSTRACT FROM AUTHOR]

The propagation of citrus seedlings is accomplished through grafting, utilizing seeds for the production of rootstocks. The germination of certain seeds may be low and uneven, complicating the production of high-quality seedlings. The use of plant growth regulators (PGRs) is a viable alternative to improve the quality of seedling production, as these compounds can break dormancy, control the hydrolysis of reserves, induce cell division, and regulate permeability and protein functions. This study aimed to evaluate the germination of seeds and the growth of Rangpur lime (Citrus limonia L. Osbeck) seedlings under the influence of imbibition in solutions of gibberellic acid (GA3) and a combination of GA4+7 + 6Benzyladenine. The experiment was conducted under controlled laboratory and greenhouse conditions, using a completely randomized design in a 2 × 5 factorial scheme, with two types of plant regulators (GA3 and GA4+7 + 6BA) at five concentrations (0, 250, 500, 750, and 1000 mg L−1 a.i.). Quantitative and qualitative variables were evaluated, ranging from seed germination to seedling development and formation, including germination percentage and speed index, fresh and dry biomass of roots and shoots, enzymatic activity, and gas exchange. The results indicate that GA3 significantly accelerates the germination process of Rangpur lime cv. Santa Cruz seeds and promotes better seedling growth and development, resulting in vigorous seedlings. These findings demonstrate that the application of PGRs, particularly GA3, can substantially enhance the propagation efficiency of citrus rootstocks, offering a practical solution for improving the uniformity and quality of seedling production in commercial settings. [ABSTRACT FROM AUTHOR]

Traditional deep learning methods employing 2D images can only classify healthy and unhealthy seedlings; consequently, this study proposes a method by which to further classify healthy seedlings into primary seedlings and secondary seedlings and finally to differentiate three classes of seedling through a 3D point cloud for the detection of useful eggplant seedling transplants. Initially, RGB images of three types of substrate-cultivated eggplant seedlings (primary, secondary, and unhealthy) were collected, and healthy and unhealthy seedlings were classified using ResNet50, VGG16, and MobilNetV2. Subsequently, a 3D point cloud was generated for the three seedling types, and a series of filtering processes (fast Euclidean clustering, point cloud filtering, and voxel filtering) were employed to remove noise. Parameters (number of leaves, plant height, and stem diameter) extracted from the point cloud were found to be highly correlated with the manually measured values. The box plot shows that the primary and secondary seedlings were clearly differentiated for the extracted parameters. The point clouds of the three seedling types were ultimately classified directly using the 3D classification models PointNet++, dynamic graph convolutional neural network (DGCNN), and PointConv, in addition to the point cloud complementary operation for plants with missing leaves. The PointConv model demonstrated the best performance, with an average accuracy, precision, and recall of 95.83, 95.83, and 95.88%, respectively, and a model loss of 0.01. This method employs spatial feature information to analyse different seedling categories more effectively than two-dimensional (2D) image classification and three-dimensional (3D) feature extraction methods. However, there is a paucity of studies applying 3D classification methods to predict useful eggplant seedling transplants. Consequently, this method has the potential to identify different eggplant seedling types with high accuracy. Furthermore, it enables the quality inspection of seedlings during agricultural production. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L. cv. Zhongza NO. 9) was used as the experimental material to investigate the effects of nocturnal LED supplemental light with the photosynthetic photon flux density (PPFD) of 100, 200, 300 μmol·m−2·s−1, and the light time of 1, 2 h on the seedling quality in a controlled environment, with seedlings without nocturnal supplemental lighting serving as the control. The results demonstrate that an increase in PPFD at night progressively enhances the plant height and leaf number of tomato seedlings, while stem diameter and leaf area initially increase and subsequently decrease. Although light time and light period-of-time at night did not significantly affect seedling morphology, PPFD and light time notably influenced chlorophyll content and net photosynthetic rate. An optimal lighting energy amount at night augmented photosynthetic capacity. However, excessive PPFD induced photoinhibition in the leaves. Additionally, appropriate nocturnal LED supplemental lighting significantly improved the antioxidant capacity of the seedlings, increased proline content, reduced malondialdehyde content, and bolstered the self-protection mechanisms of the seedlings against nocturnal light stress. Both the PPFD and light time at night promoted biomass accumulation in tomato seedlings. Specifically, when supplemental lighting was applied for 2 h at an intensity of 200 μmol·m−2·s−1, both the fresh and dry weights of the shoot and root significantly increased, and the seedling health index was highest. Therefore, appropriate nocturnal LED supplemental lighting positively impacts the health index and photosynthate accumulation of tomato seedlings, but controlling PPFD is essential to avoid photoinhibition. [ABSTRACT FROM AUTHOR]

Papaya (Carica papaya L.) is a widely cultivated and consumed fruit. When forming papaya seedlings, the combination of the ideal substrate to obtain quality seedlings is essential. The objective of this study was to evaluate the effect of a combination of substrates formulated with coconut fiber and doses of calcareous algae on the initial growth of papaya seedlings (Carica papaya L.). The experimental design was completely randomized in a 3 × 5 factorial arrangement, with five replications. The treatments consisted of the following substrate formulations: full coconut fiber + Gypsum; coconut fiber powder + NPK (15-10-10); coconut fiber powder + Gypsum; and doses of calcareous algae (0, 15, 30, 45 and 60 mg dm−3) applied as cover. The plant height, stem diameter, leaf area, number of leaves, shoot dry mass, root length and dry mass, and relative chlorophyll content (Chlorophyll A and Chlorophyll B) at 40 days of application of calcareous algae were evaluated. Substrates formulated with coconut fiber powder plus gypsum associated with calcareous algae doses are a great alternative in the production of papaya seedlings, stimulating plant height, stem diameter, number of leaves, and root dry mass. [ABSTRACT FROM AUTHOR]

In order to establish protocols that can contribute to the propagation of medicinal plants, this study evaluated the effect of hydropriming and substrates on the emergence and production of Calendula officinalis L. seedlings. Seeds were submitted or not to hydropriming for 24 hours, and subsequent sowing in four substrates: S1) 100% Dystroferric Red Latosol -- DRL, S2) DRL + coarse sand (1:1 v/v), S3) DRL + Tropstrato® commercial substrate (1:1 v/v) and S4) 100% Tropstrato®, and kept in greenhouse with 50% shading. Higher emergence percentage in substrates with the presence of DRL was observed. Seed hydropriming impaired seedling emergence, but contributed to root growth, biomass production and seedling quality. The 100% Tropstrato® substrate favored higher dry mass production and seedling quality. Positive linear correlation (≥ 0.70) was observed between shoot and root growth characteristics with biomass production and Dickson's quality index. Principal component analysis explained 78.95% of the experimental variance, excluding the first count and the shoot/root ratio with low representativeness. In the cluster analysis of Euclidean distances, seedlings with the greatest similarity were those produced with 100% DRL and DRL + Tropstrato® with and without hydropriming, respectively. Dystroferric Red Latosol is recommended pure or combined with Tropstrato® for the production of C. officinalis L seedlings, and the hydropriming impaired seedling emergence characteristics. [ABSTRACT FROM AUTHOR]

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Atractylodes Chinensis (DC) Koidz is a perennial herb often used as a prescription medicine for influenza, to invigorate the spleen and remove dampness. The quality of the herb is determined by the quality of the seedlings. The traditional A. chinensis seedling production technique has nonuniform seedlings and low mechanisation. The plug seedling technique was used to produce A. Chinensis seedlings. This study was conducted to determine the growth characteristics of A. Chinensis seedlings according to the cell size of plug trays and number of days after sowing. Plant height, stem diameter, rhizome diameter, number of leaves, leaf area, and shoot dry and fresh weight of A. Chinensis seedlings were significantly higher in the P32-D treatment than in the P72, P50, and P32 treatments, but not significantly different from the P28-D treatment 60 d after sowing. The P28-D treatment resulted in a considerable drop in rhizome fresh weight and healthy seedling index, both of which are key indicators for assessing seedling quality. Although the differences in Pn among treatments were not significantly different, Tr was considerably greater in A. Chinensis seedlings treated with P32-D and P28-D than in the other three treatments. The P32-D and P28-D treatments had considerably greater potential maximum photochemical efficiency of PSII, quantum yield of photosystem II, photochemical quenching and electron transport rate than the other three treatments. Root vitality of A. Chinensis seedlings was significantly stronger in the P32-D treatment than in the other four treatments, and it was 1.9 times higher than in the P28-D treatment. The soluble protein, soluble sugar, and starch contents of A. Chinensis seedlings were highest in the P32-D treatment, but the differences among treatments were not significant. LUE, EUE, PY and EY were significantly higher in the P32-D treatment than in the other four treatments, being 1.3, 1.3, 1.4 and 1.4 times higher than in P28-D, respectively. On the other hand, as for the change in the growth of A. Chinensis seedlings according to the number of days after sowing, the growth of shoots and rhizome was most vigorous at the 60 d after sowing, while the fresh weight of the rhizome, which can be considered as an indicator of root growth, increased steadily during the experiment but slowed down after 60 d. As a result, 32-cell deepened plug trays and a seedling nursery for a period of 60-75 d are recommended for commercial cultivation of A. Chinensis seedlings. This will provide technical support for production in A. Chinensis seedling. [ABSTRACT FROM AUTHOR]

Background: Groundnut is one of the most important oilseed crops and also a good source of proteins, carbohydrates and fibre. Conventionally, groundnut cultivation also need good amount of commercial nitrogen fertilizers which are found to be not efficiently and effectively utilized by the plants, also lost due to leaching and so, causing severe ecological damage. However, our study of priming groundnut seeds with nanofertilizers have reduced the dosage of fertilizers as well as increased the yields. Methods: A two-year field experiment (2020-2021) was carried out to evaluate the effect of nano fertilizers (NF) (phosphorus, zinc, and iron) seed priming and NF foliar spray on the growth, yield, and seed quality characteristics of groundnut var TG-37 A. Groundnut was chosen as the testcrop and seeds were primed with nanofertilizers as well as standing crop is foliar sprayed with nanofertilizer at pre-flowering stage. The effect of nanofertilizers on test crop was evaluated on seed germination, seedling vigor, plant growth, flowering, chlorophyll content, pod yield, oil content and protein content. Result: The results indicated that in both the years, NF seed primingandfoliar sprays treatments showed higher seed germination and seedling vigor aided in early establishment in soil, which manifested by higher plant height, early flowering, higher leaf chlorophyll content, 100-seed weight and shelling percentage. Pod yield per plant was 30.1% and 33.0% higher in 2020 and 2021, respectively, as compared to the control. In both years, the application of nano fertilizers considerably boosted the oil and protein content compared to the control (31.5% and 28.9% for oil, 33.1% and 30.0% for protein). Thus, it is concluded that nano-fertilizers considerably improved growth, yield and quality of groundnut. [ABSTRACT FROM AUTHOR]

Rapeseed (Brassica napus L.) seedlings suffering from inappropriate growth substrate stress will present poor seedling quality. However, the regulatory mechanism for the production and scavenging of reactive oxygen species (ROS) caused by this type of stress remains unclear. In the current study, a split plot experiment design was implemented with two crop growth substrates—a rice growth substrate (RIS) and rapeseed growth substrate (RAS)—as the main plot and two genotypes—a hybrid and an open-pollinated variety (Zheyouza 1510 and Zheyou 51, respectively)—as the sub-plot. The seedling quality was assessed, and the ROS production/scavenging capacity was evaluated. Enzymatic and non-enzymatic systems, including ascorbic acid and glutathione metabolism, and RNA-seq data were analyzed under the two growth substrate treatments. The results revealed that rapeseed seedling quality decreased under RIS, with the plant height, maximum leaf length and width, and aboveground dry matter being reduced by 187.7%, 64.6%, 73.2%, and 63.8% on average, respectively, as compared to RAS. The main type of ROS accumulated in rapeseed plants was hydrogen peroxide, which was 47.8% and 14.1% higher under RIS than under RAS in the two genotypes, respectively. The scavenging of hydrogen peroxide in Zheyouza 1510 was the result of a combination of enzymatic systems, with significantly higher peroxidase (POD) and catalase (CAT) activity as well as glutathione metabolism, with significantly higher reduced glutathione (GSH) content, under RAS, while higher oxidized glutathione (GSSH) was observed under RIS. However, the scavenging of hydrogen peroxide in Zheyou 51 was the result of a combination of elevated oxidized ascorbic acid (DHA) under RIS and higher GSH content under RAS. The identified gene expression levels were in accordance with the observed enzyme expression levels. The results suggest that the cost of substituting RAS with RIS is a reduction in rapeseed seedling quality contributing to excessive ROS production and a reduction in ROS scavenging capacity. [ABSTRACT FROM AUTHOR]

Introduction: Valeriana amurensis, a tall herbaceous plant, has been traditionally utilized as a herbal remedy both in China and Russia. Methods: This study was set to explore how to cultivate high quality seedlings, considering factors such as seedling time, seeding density, shading, and plastic film mulching. In addition, we investigated the impact of topping and fertilizer on the growth and quality of V. amurensis. Results: According to the percentage of seed germination, the seeds of V. amurensis were sowed with 0.88 g m-2 density using plastic film mulching from late April to mid-May (germination percentage was more than 30%). The optimal Transplanting time was identified as late September, ensuring a high survival rate of 98%. Generally, topping showed the most improved growth indices in late fruit period (21.87 for number of radical leaves) and withering period (6.50 for number of buds and 234.81 for number of roots). Topping increased the yields of valtrate (10.91 mg per plant), valepotriates (809.51 mg per plant) and essential oil (395.64 mg per plant) in withering period. Nitrogen fertilizer promoted maximum root growth and increased the biomass of V. amurensis. Meanwhile, N fertilizer significantly increased the yields of valtrate to 10.46 mg per plant and valepotriates to 772.32 mg per plant among three types of fertilizers. Seedlings are obtained according to rational sowing factors and transplanting time. Topping and nitrogen fertilization emerge as superior strategies to enhance the growth and medicinal quality of this valuable plant. Discussion: This study provides actionable insights for the cultivation V. amurensis. [ABSTRACT FROM AUTHOR]

【Objective】Caladium bicolor is a foliage plant in the Araceae family, characterized by rich colors and diverse patterns on its leaves, making it widely used for indoor and outdoor ornamental purposes and possessing good economic value. C. bicolor is often cultivated in greenhouses without additional lighting measures, which limits the quality and efficiency of seedling production due to weather conditions, making it difficult to guarantee the production efficiency and standardization of commercial seedlings. Light is an important factor in the growth and pigment accumulation of C. bicolor. The study aims to explore suitable types of light quality for tissue-cultured C. bicolor seedlings, providing a theoretical basis for improving the production efficiency and seedling quality of C. bicolor plants.【Method】We used white fluorescent light as a control and employed 7 different light quality types including LED white light, LED red light, LED blue light, LED red-blue-white 1:1:1, LED red-blue-green 1:1:1 and LED red-blue-white-green 1:1:1:1 light to treat tissue-cultured regenerated plants of C. bicolor. Various growth indicators such as leaf size, leaf thickness, plant height, number of roots, and pigment content of C. bicolor after different light quality treatments were measured to evaluate and select effective light qualities that could enhance the quality of commercial C. bicolor seedlings.【Result】Compared to fluorescent light, LED red light treatment was detrimental to the increase in the number of leaves and the thickness of petioles in C. bicolor, which were 5.3 pieces and 3.42 mm, respectively; it hindered the accumulation of total chlorophyll content and relative anthocyanin content on the leaf surface, which were 2.0 mg/g and 1.0 U/g respectively; and it was also unfavorable for the maximum photochemical efficiency of PSII (Fv/Fm) and the actual quantum yield of photosystem II〔Y(II)〕, with values of only 0.64 and 0.60, respectively. LED blue light treatment promoted the increase in plant height, petiole thickness and accumulation of relative anthocyanin content in C. bicolor, which were 21 cm, 4.6 mm and 6.1 U/g, respectively. However, it was not beneficial for the increase in the number of roots in C. bicolor. For the light combination treatment, LED red blue white green 1:1:1:1 was beneficial for the increase of leaf area, reaching 98.8 cm² . The relative anthocyanin content on the leaf surface was highest under this treatment, reaching 8.23 U/g. LED red blue green 1:1:1 treatment was not conducive to increasing plant height, petiole thickness and leaf thickness, which were 10.6 cm, 3.9 mm, and 0.70 mm, respectively. The relative anthocyanin content on the petioles of C. bicolor under LED red blue white 1:1:1, LED red blue green 1:1:1, and LED red blue white green 1:1:1:1 treatments was significantly lower than that under white fluorescent lamp light treatment.【Conclusion】Different light qualities influence the growth and pigment accumulation of regenerated plants of C. bicolor. LED blue light treatment is the most effective in increasing plant height, petiole thickness and relative anthocyanin content in C. bicolor. LED red blue white green 1:1:1:1 treatment is the most effective in increasing leaf area and relative anthocyanin content on the leaf surface. By selecting the appropriate light quality ratio based on actual conditions in production, the efficiency of standardized production of C. bicolor seedlings can be effectively improved [ABSTRACT FROM AUTHOR]

Junipers (Juniperus sp.) have 1.56 million ha natural distribution which of total 23.3 million ha Turkish forest area. However, 1.1 million ha (71%) of junipers and 9.6 million ha (41%) of Turkish forest area is unproductive. Seedling quality and morphology is one of the important tools in conversion of unproductive forest to productive forest. Seedling quality and morphology were investigated based on seedling height and root-collar diameter, and sturdiness index of 2+0 years containerized and bare-root seedlings of Crimean juniper (Juniperus excelsa Bieb.) grown at Forest Nursery from southern Türkiye. For the purpose, 150 seedlings were sampled randomly from each seedling type in a forest nursery to collect seedling height and root-collar diameter data. Sturdiness index was calculated by ratio between the height and diameter. Collected data was performed for comparison of the seedling types for the characteristics by one-way analysis of variance, and to be determined relations among the characteristics by correlation analysis. The seedlings were distributed to quality classes of Turkish Standard Institute and Sturdiness index. Studied bare-root seedlings (16.3 cm) showed higher height growth performances than containerized (14.5 cm) seedlings opposite to root-collar diameter (2.04 mm and 1.86 mm), while the seedlings showed large differences within seedling type for the characteristics. Averages of sturdiness index were 72.5 and 88.5 in containerized seedlings and bare-root seedlings, respectively. Seedling types indicated significant (p=0.05) differences for the characteristics. Positive and significant (p=0.05) phenotypic relations were estimated among the characteristics in seedling types. Distribution of seedlings to quality classes varied for the characteristics, classes and seedling type. Results of the study were discussed based on nursery practices and plantation forestry of the species. [ABSTRACT FROM AUTHOR]

The cagaiteira (Eugenia dysenterica DC.) is an important fruit species native from Brazilian Cerrado that has economic potential for food and pharmaceutical sectors and the recovery of degraded areas. Knowledge about crop management is still limited, including fertilization methods. This study aimed to evaluate the effect of lime and phosphorus (P) application on nutrition, growth, dry matter production and physiological aspects of cagaiteira seedlings. The experiment was conducted in a greenhouse, using a randomized block design with three replications, in a 5x4 factorial scheme, five base saturation levels (24.5, 40.0, 60.0, 80.0 and 100.0%) and four P rates (0, 100, 200 and 400 mg dm-3). At 180 days after transplanting, gas exchange, biometrics (diameter, height and leaf area), dry mass production, seedling quality (Dickson Quality Index - DQI) and nutrient content were evaluated. The results were subjected to analysis of variance (p<0.05) and regression model adjustments. The growth and physiology of Eugenia dysenterica DC seedlings are not influenced by liming; however, the application of lime positively influences the B content in the plants. Phosphate fertilization increases growth in height, with an estimated rate of 245 mg dm-3 of P indicated to produce cagaiteira seedlings, since at this dose is estimated that the plant will be taller. In general, cagaiteira proves to be a species that develops well in acid soil conditions and with low availability of P. [ABSTRACT FROM AUTHOR]

Citriculture has developed a lot, bringing with it the development of orange processing industries, however, the generation of waste in this industrial activity is high. The objective was to evaluate the tolerance of Psidium guajava in soil contaminated with copper and the addition of orange bagasse. The experiment was conducted from 01/2021 to 09/2021, and the treatments consisted of 3 proportions of bagasse incorporated into the soil, and contaminated with different concentrations of copper, and transplanted seedlings. Dry mass, copper content in compost and tissues, copper accumulated in tissues and translocation index were determined. The experimental design was completely randomized in a factorial scheme. Copper contamination promoted increases in the total copper contents of the compost, and the proportion of 50% of residue showed higher values. Copper interfered with the development of seedlings, reducing the dry mass, and increasing the levels of copper accumulated in the plants. The proportions of 25 and 50% of residue promoted reductions in the levels of accumulated copper in the roots and total, and in the shoot, the proportion of 25% of residue promoted an increase in the levels of accumulated copper in comparison to the others. The translocation index reduced with the increase of copper in the compost and presented lower values in the proportion of 0% of residue. The addition of 50% of residue and the concentrations of 200 and 400 mg Cu.Kg-1 promoted reductions in the quality of the seedlings, verified through decreases in dry mass, in addition, through the translocation index, Psidium guajava did not show any if a viable plant for phytoremediation. [ABSTRACT FROM AUTHOR]

In order to study the effects of top pruning time and retained stem height on the quality of Pinus koraiensis seedlings, a top pruning test was carried out with 4-year bare root seedlings of Pinus koraiensis as materials, and 3 retained stem heights （20, 25, 30 cm） and 5 top pruning times （April, May, June, July, August） were set. The root collar diameter, biomass, shoot to root ratio, root length, root surface area and root volume of seedlings under different top pruning treatments were measured. The results showed that top pruning treatment in the middle of the growing season （June） could significantly increase the root collar diameter growth of Pinus koraiensis seedlings by 23. 68% compared with the control, but the effect of top pruning treatment at other times was not obvi‐ ous. The top pruning treatment had no effect on the increase of biomass, the decrease of shoot to root ratio and the growth of thick roots, but had a significant effect on the growth of fine roots of Pinus koraiensis seedlings. The length of fine roots, surface area of fine roots and volume of fine roots were increased by 18. 27%-84. 95%, 9. 38%-75. 01% and 1. 28%-64. 68%, respectively, compared with the control. The top pruning in the middle of the growing season （June） increased the root collar diameter growth of Pinus koraien⁃ sis seedlings, promoted the growth of fine roots and promoted the quality of Pinus koraiensis seedlings to a certain extent. [ABSTRACT FROM AUTHOR]

Machine transplanting has been the primary technique of rice seedlings in cultivation in recent years. Among them, factory-scale greenhouses have been commonly used for seedling cultivation in northern China. By contrast, paddy-field seedling can be widely used to cultivate rice transplanting in southern China, according to climate, environment, and production costs. However, manual seedlings are limited to the high labor intensity and the waste of chemical fertilizers and pesticides. It is very necessary to improve the irrigation uniformity in the management of water-fertilizer-pesticide in rice paddy fields. In this study, a variable-rate spraying device was designed for water-fertilizer-pesticide irrigation in rice seedlings. A systematic analysis was performed on the large variable-rate sprinkler and the supporting equipment of fertilizer injection at a high-quality level. The overall structure and working principle were clarified for the variable-rate spraying irrigation device of waterfertilizer-pesticide for seedlings; FLUENT software was used to conduct numerical simulation on the sprinkler irrigation variable-diameter pipeline, in order to determine the optimal structural layout of variable-diameter pipeline; The flow rate of sprinkler and the inlet water of main pipe were then determined after experiments. The curved surface model was established for the pressure and electric ball valve opening; A fertilizer injection and dosing mechanism were designed using proportional integral derivative (PID) self-tuning. The real-time equal-proportion fertilizer or medicine injection was realized after optimization. The online control system of fertilizer injection and variable-rate spraying was constructed with the mitsubishi programmable logic controller (PLC) as the control core. The Box-Behnken experiment was adopted to explore the uniform performance and influencing factors of the device for spraying irrigation. The single objective optimization was applied to determine the key parameters of the device for sprinkler irrigation. The optimal combination of parameters was obtained as follows: The inlet water pressure of the main pipe was 0.20 MPa, the electric ball valve opening was 90°, and the nozzle spraying angle was 80°. Christiansen uniformity of the device was 92.69% in this case; There was a linear model between the mass concentration and electrical conductance (EC) value of the potassium chloride fertilizer solution. The variable-rate irrigation and fertilization experiments were conducted on the device. The EC values of the water-fertilizer mixture were 1.65, 1.66, and 1.68 mS/cm, respectively, in the three spraying irrigation levels. The average values of sprinkler intensity were 900.85, 1092.04, and 1263.67 mm/h, respectively. The fertilization uniformity coefficients were 85.21%, 87.86%, and 91.62%, respectively. There was a small fluctuation of EC values for the water-fertilizer mixtures under the three sprinkler irrigation levels of Ⅰ, Ⅱ, and Ⅲ. The average irrigation intensity of sprinklers varied greatly, where the coefficient of uniformity of fertilizer application was higher than 85%. The field test of rice seedlings was carried out using the variable-rate spraying device of water-fertilizer-pesticide for seedlings. The rice varieties were selected as Huahang51 conventional rice and Guang8You165 hybrid rice. The uniformity of seedling growth was higher than 95% at 13, 21, and 28 d after seeding. There were excellent quality indexes and rooting performance of the seedlings. The various quality indicators of rice seedlings fully met the requirements of machine transplanting. The experiment results showed that the variable-rate spraying device of waterfertilizer-pesticide system shared an accurate, real-time, and proportional fertilizer injection, irrigation, and pesticide spraying in rice paddy fields. The finding can provide a practical application to improve the mechanization level of rice paddy field seedlings for the high-quality of seedlings. [ABSTRACT FROM AUTHOR]

A new leaf blight disease in Schleichera oleosa seedlings was detected in a Kerala state forest nursery, India. Through morphological, cultural characterization, and multi-gene phylogenetic analysis, the fungal pathogen was identified as Pseudopestalotiopsis camelliae-sinensis, the first report on Schleichera in India. Koch's postulates were fulfilled. Research attention is required to manage emerging seedling diseases for quality planting materials. [ABSTRACT FROM AUTHOR]

To achieve high-density tomato seedlings in a plant factory with artificial lighting, tomatoes (Solanum lycopersicum Mill. cv. "Zhongza NO.9") were used as the experimental material. This study expected to analyze the effects of light intensity (150, 200, 250, and 300 μmol·m−2·s−1) and light time (12 and 14 h), as well as daily light integral (DLI, 10.80, 12.60, and 12.96 mol·m−2·d−1) and sowing density (50, 72, and 105 holes per tray), on seedling quality. The results indicated that biomass accumulation, seedling quality, and energy use efficiency of seedlings significantly improved with an increase in DLI. At a DLI of 12.96 mol·m−2·d−1, seedlings sown at a density of 72 holes per tray exhibited comparable growth characteristics and biomass accumulation to those sown at 50 holes per tray. However, under lower DLIs, seedlings at 50 holes per tray displayed superior growth morphology and seedling quality compared to those at 72 holes per tray. This indicates that increasing the DLI can partially mitigate the negative effects of higher sowing density on seedling quality. Light use efficiency (LUE) and energy use efficiency (EUE) were not significantly different between seedlings at 72 and 105 holes per tray but were higher than those at 50 holes per tray. Therefore, optimizing parameters such as DLI and sowing density can effectively enhance the seedling quality, spatial use efficiency, and light use efficiency in industrial seedling production. Based on the results of this study, a DLI of 12.96 mol·m−2·d−1 (achieved with a light intensity of 300 μmol·m−2·s−1 and a light time of 12 h) and sowing density of 72 holes per tray are recommended for cultivating high-quality tomato seedlings while reducing energy consumption. [ABSTRACT FROM AUTHOR]

Pinus pinea is an interesting species due to its pine nuts. Tuber borchii, a fungus that produces truffles, is a delicacy. Both species association offers a new productive opportunity. This work evaluated the effect of fertilization and inoculation with T. borchii on stone pine seedling growth in nursery and one year after field establishment in Chile, as well as mycorrhizal persistence. A factorial trial with two factors, inoculation and fertilization, was conducted in nursery. Mycorrhization, seedling growth, biomass and needle nutrient concentration after one growing season were measured. Mycorrhization and plant growth were measured one year after establishment a multi-environment trial involving seven sites. In nursery, inoculated seedlings presented over 50% of mycorrhized root apexes, with no differences between fertilized and non-fertilized plants. Under fertilization, inoculated plants had 16.5% higher height than non-inoculated ones. Fertilization increased seedling growth independently of inoculation. Inoculation did not modify the aerial to root biomass ratio. Inoculated and non-fertilized plants showed statistically higher P and lower K in needles than non-inoculated seedlings. One year after establishment, inoculation favored plant growth, and plants presented on average 88% of root apexes mycorrhized with T. borchii. Fertilization did not affect plant growth or mycorrhization levels. Stone pine inoculation with T. borchii was successful to produce abundantly mycorrhized roots in nursery. One year after field establishment, plant height and crown diameter were enhanced by inoculation, and high mycorrhization level suggests future truffle harvests. Both P. pinea and T. borchii showed high adaptability to different environments. Key message: Stone pine (Pinus pinea) seedlings non-inoculated and inoculated with Tuber borchii were produced in nursery with and without fertilization, and established in seven field trials in central-southern Chile. Before planting, inoculated seedlings presented abundantly mycorrhized root systems, and fertilized plants showed higher height and root collar diameter, independently of inoculation, than non-fertilized ones. One year after plant field establishment, mycorrhization had a positive effect on plant growth, and T. borchii colonization was higher than in nursery. Fertilization did not affect growth or mycorrhization level. The results have practical implications for trufficulture and pine nut production in non-native habitats. [ABSTRACT FROM AUTHOR]

Purpose: Millicompost is an organic substrate generated by the activity of millipedes (diplopods) with high potential for seedling production. This work aimed to evaluate the performance of green curly lettuce (Lactuca sativa L.) using seedlings produced with millicompost, at different levels of nitrogen (N) fertilization at seedling transplant, in an organic production system. Method: A field experiment was carried out in Seropédica, Rio de Janeiro State, Brazil, in a 2x4 factorial design with four replications, combining seedlings produced with two substrates (millicompost or Biomix®- used as reference) and four levels of N fertilization with castor cake (0, 50, 100 and 200 kg N ha-1) at seedling transplant. Plants were sampled weekly, and lettuce production was evaluated at 42 days after transplant. Results: Seedlings produced with millicompost had root dry mass, plant height, and number of leaves higher than those produced with commercial substrate. At levels 0 and 50 kg N ha-1, lettuce plants originating from seedlings produced with millicompost showed a higher growth rate than those with the commercial substrates, between 35 and 42 days after transplant. Fresh commercial weight, head diameter, and number of leaves of lettuce plants increased linearly as applied N levels increased. These traits were superior in plants from seedlings produced with millicompost than with commercial substrate. Conclusion: The millicompost provided seedlings of improved quality that increased the growth and yield of lettuce plants in the field at different levels of N fertilization. [ABSTRACT FROM AUTHOR]

ABSTRACT: The structure of the root system of the conilon coffee tree has improved over the years through propagation, genetic, and agronomic studies in response to demands for improvements in plant development, production, and survival of the species. Scientific research plays an important role in generating technologies and the security of applications. However, there is a need to refine the content generated to analyze discoveries and trends on the subject. Therefore, the present study conduct a bibliometric review and analysis on the main contributions of relevant studies, researchers, organizations, and countries in academic research on the rooting of Coffea canephora in the Web of Science (WOS) database. Data from the WOS database published between 1982 and 2021 and systematized in the VOSviewer software showed a set of 92 articles, the majority of which originated in Brazil and France, with the main groups being the Brazilian Agricultural Research Corporation, the Federal University of Viçosa, and CIRAD. The study was divided into five areas: genetic diversity, asexual propagation, nematology, tolerance to water stress, and micropropagation. However, in the context of climate changes and its impact on the production and longevity of Brazilian coffee farming, research focused on the root system has increased significantly, integrating it into lines that explore and integrate topics such as climate risk, water management, drought tolerance, and drip irrigation, including reflections on the performance of coffee agronomy.

To determine the appropriate seeding rate for machine-transplanted hybrid rice, field experiments were conducted during 2022–2023 using the hybrid rice variety Huazhe You 210 as the material. Four seeding rate treatments were set up: 40 (T1), 60 (T2), 80 (T3) and 100 g tray-1(T4), to investigate the effects of seeding rate on the seedling quality, transplanting quality, yield formation, and economic benefits of high-quality indica hybrid rice seedlings. The results showed that with increasing seeding rate, the seedling base stem diameter and seedling plumpness of hybrid rice seedlings decreased, but the root entwining force gradually increased, leading to a deterioration in individual seedling quality but an improvement in collective characteristics. As the seeding rate increased, the missing hill rate during mechanical planting of hybrid rice significantly decreased, while the number of seedlings per hill and the damaged seedling rate showed an upward trend. The growth volume of tillers, tillering spikelet rate, and harvest index of hybrid rice in the field showed an overall downward trend with increasing seeding rate, while the accumulation of dry matter initially increased and then decreased. The yield and economic benefits of hybrid rice grains showed an initial increase followed by a decrease with increasing seeding rate, with the highest yield and economic benefits achieved with the T2 treatment. In conclusion, the appropriate seeding rate for machine-transplanted hybrid rice is T2 (60 g tray-1), which can maintain good seedling quality and improve transplanting quality, coordinate larger collective growth and appropriate harvest index, contributing to high yield and good economic benefits. [ABSTRACT FROM AUTHOR]

Currently, large quantities of spent mushroom substrate (SMS) are produced annually. Because SMS has high water retention and nutrients, it has great potential to replace traditional topsoil for raising seedlings in agricultural production. However, few studies have examined the effects of substituting SMS for paddy soil on rice seedling growth and soil nutrients. SMS was mixed with rice soil in different proportions (20%, 50%, and 80%), and chemical fertilizer, organic fertilizer, and peat substrate were added in addition to equivalent nitrogen as a traditional seedling nursery method for comparison. Compared to traditional paddy soil (CK), the seedling qualities of the three SMS ratio treatments were all higher. Adding SMS at different ratios promoted rice seedling root growth, elevated the soluble protein concentration, and amplified the superoxide dismutase (SOD) enzymatic action in rice seedlings. Total porosity and aeration porosity of the soil increased by 17.40% and 32.90%, respectively. Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) increased by 21.26–118.48%, 50.44–71.68%, and 23.08–80.17%, respectively. Besides, the relative abundance of Bacillus, Bacteroidetes, and other bacteria as well as the abundance of Ascomycota were all significantly increased. Adding 50% SMS increased the abundance of Pseudomonas by 8.42 times. The seedling quality of the 50% SMS treatment was even higher than chemical fertilizer and organic fertilizer treatments, only second to the peat substrate treatment. In summary, partial substitution of paddy soil with SMS can ameliorate substrate properties, improve seedling quality, and increase microbial diversity, indicating the suitability of SMS as a replacement for rice soil in seedling substrates. The 50% SMS ratio is the best. This study provides a basis for SMS to replace traditional rice soil in seedling cultivation. [ABSTRACT FROM AUTHOR]

Background: Acacia nilotica var. cupressiformis is an evergreen multipurpose leguminous tree species which is suitable to agroforestry purposes and mainly distributed in Western parts of Rajasthan in India particularly Pali and its adjoining areas. The species has many advantages, however the natural germination in wild is very limited due to its hard seed coat dormancy. Methods: The experiment was conducted to study the effect of presowing treatment on seed coat of A. nilotica var. cupressiformis seeds with ten treatments in completely randomized block design at ICAR-Central Arid Zone Research Institute, Regional Research Station, Pali Marwar. The treatments were replicated thrice. Result: Among the treatments, maximum germination and higher values was obtained in sand paper scarification with water soaking for 12 hrs (T2) followed by mechanical scarification with sand paper (T1), acid scarification (50% for 20 min) (T7) and acid scarification (98% for 10 min) (T5). Further, the present study aims to initiate the research areas for conservation and utilization of A. nilotica var. cupressiformis in Western parts of Rajasthan and other parts of India. [ABSTRACT FROM AUTHOR]

Background: Forages of high quality are the most valuable commodity of any livestock activity and they serve as the basis for most of the rations in a forage-based diet. The lack of good quality seedlings/seeds, notably improved varieties, is the primary reason for the slow adoption of improved forage production technologies. Traditional establishment of bajra napier forage incurs more labour costs, harvesting sett material, transporting, preparing two budded setts and carrying to the planting area. Nearly three to four tons of green leaves stem materials are wasted for planting one hectare of area. In this situation, an alternate method is required to produce high-quality seedlings in a short period. This research objective compared single node bud chip seedling in different protray cell cavities and pot mixtures. Methods: The green shade net field study was carried out between 2019 and 2020, the effect of different pro-tray sizes (50, 60 and 98 cell cavities) and potting mixture (red earth, cocopeat, farmyard manure, vermicompost and root growth promoters like phosphobacteria bio-fertilizer and indole acetic acid (IAA) was taken in different combination for the establishment of Bajra Napier hybrid variety Co (BN)-5 seedling by using single node bud chip technology. The observation was taken up to 30 days in related to seedling growth and development. The observed parameter was statistically analysed in SPSS software. Result: Among the three different protray cavities and five different pot mixtures, 60 cavity protray with red earth + cocopeat + vermicompost (2:1:1) results revealed significant differences (p>0.05) in seedling growth parameters among the different protray and growing media. The maximum seedling growth parameters like germination, numbers of the leaf, plant height, leaf length, width and root length (94.4 per cent, 8.17, 39.12 cm, 38.14 cm, 2.5 cm and 30.8 cm) were observed at 30 days aged seedlings followed by red earth + cocopeat + farmyard manure (2:1:1 ratio) and treated with IAA substance in 60 cavity protray. [ABSTRACT FROM AUTHOR]

The production of coconut tree seedlings is an important step in the production process, as it substantially affects the productive performance of the adult plant, and the way of obtaining seedlings directly reflects the added costs. To minimize costs, the introduction of biostimulants can be considered a viable and sustainable technology. This study aimed to evaluate the effects of applying Bacillus cereus in promoting growth and reducing the costs of producing Brazilgreen dwarf coconut seedlings. The study has two stages, the first was an experiment carried out in a commercial nursery in the state of Pará-Brazil. The design was completely randomized, with two treatments: control with water (100% mineral fertilization) and B. cereus inoculation (50% mineral fertilization), with 10 replicates each. Biometric parameters and the quality of seedlings were evaluated. In the second stage, the production of stimulated seedlings was compared to that of commercial seedlings, and the effective operating cost (COE) and the total operating cost (TOC) were determined. Biostimulation with B. cereus promotes the growth of coconut tree seedlings, increases seedling quality, and reduces nursery time. In addition, the cost of production is reduced by 10%. Thus, microbial technology is a positive strategy for the production of Brazilian green dwarf coconut seedlings. Using B. cereus can guarantee obtaining seedlings with high performance and at a lower cost. These results may favor obtaining adult plants with high productivity. [ABSTRACT FROM AUTHOR]

Improving the quality of tree planting material for carbon sequestration through reforestation can help solve environmental problems, including the need to reduce the concentration of carbon dioxide in the atmosphere. The purpose of this study was to investigate the possibility of using humic substances in combination with rhizosphere microorganisms Pseudomonas protegens DA1.2 and Pseudomonas sp. 4CH as a means to stimulate the growth of seedlings of pine, poplar, large-leaved linden, red oak, horse chestnut, and rowan. Humic substances stimulated the growth of shoots and roots of pine, large-leaved linden, and horse chestnut seedlings. The effects of bacteria depended on both plant and bacteria species: Pseudomonas protegens DA1.2 showed a higher stimulatory effect than Pseudomonas sp. 4CH on pine and linden, and Pseudomonas sp. 4CH was more effective in the case of chestnut. An additive effect of humates and Pseudomonas protegens DA1.2 on the growth rate of pine and linden saplings was discovered. Poplar, red oak, and rowan seedlings were unresponsive to the treatments. The growth-stimulating effects of the treatments are discussed in connection with the changes in carbon, chlorophyll, and nitrogen contents in plants. The results show the need for further research in bacterial species capable of stimulating the growth of plant species that were unresponsive in the present experiments. [ABSTRACT FROM AUTHOR]

Seaweed extracts have several functions in agriculture due to their composition that is rich in nutrients, plant hormones, and bioactive substances. It is a natural product used as a biostimulant especially to promote the growth and development of plants and their tolerance to environmental stresses. The objective of this study was to analyze the response to a biostimulant containing seaweed extract derived from Ascophyllum nodosum in the cultivation of tomato and eggplant seedlings, analyzing the growth and physiological parameters in two different regions of Brazil. Cherry tomato and eggplant were cultivated in polyethylene trays for 30 days. In each crop, five treatments were tested, comparing the use of a commercial seaweed extract in application doses and forms, which were the control (without seaweed application); 0.1%, 0.2%, and 0.3% of the seaweed extract applied by irrigation water; and treatment with 0.2% of the seaweed extract by foliar application. This study confirms the efficacy of incorporating seaweed extract from Ascophyllum nodosum as a bio-input into the production phase of Solanaceae seedlings. The seedlings which received the seaweed extract significantly increased some morphological parameters, mainly regarding the biomass and length of leaves, stems, and roots. In general, applying both methods through irrigation water and foliar application were effective in providing benefits compared to the control treatment. The intermediate dose (0.2%) was the most effective in promoting improvement in the analyzed parameters. This underscores the importance of obtaining quality seedlings for subsequent planting in the field, potentially leading to better acclimatization and initial adaptation. [ABSTRACT FROM AUTHOR]

Farming with tomatoes (Solanum lycopersicum) in South Africa can be a highly profitable operation, provided the farmer starts the crop with the right variety of quality seedlings, suited for the specific growth area. Therefore, it is necessary to study tomato seedlings on the molecular level. This study was conducted to isolate and identify S. lycopersicum in Limpopo Province, South Africa. Therefore, this molecular study was conducted in 2022 at Limpopo University. To identify S. lycopersicum 28S rDNA marker was used. The DNA was extracted using the Chelex method. The tomato was identified as S. lycopersicum. The Nblast analysis showed South African S. lycopersicum has a 99.8% similarity with a population from Germany (OU640345) and a 99.7% similarity with a population from Sweden (OK073662). Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as S. lycopersicum in the same clade with highly supported (83) bootstrap values. In conclusion, this species is identified using 28S rDNA properly. However, other DNA markers are recommended to understand Solanum spp. phylogeny better. [ABSTRACT FROM AUTHOR]

Low temperatures pose a significant threat to plant growth and development. Studies have shown that aquaporins (AQPs), as the main functional proteins on the cell membrane regulating water ingress and egress, play a vital role in maintaining dynamic water balance when plants face cold stress. Catalpa bungei, an important timber and ornamental tree species, has its cultivation range significantly limited by its poor cold tolerance. However, no study has been found aiming to identify its aquaporin gene family. This study aims to fill this gap using two C. bungei cultivars with differing cold tolerance as experimental material: "Qiuza 1", which is less cold-tolerant, and "Qiuza 2", which is more cold-tolerant. The plants were subjected to low-temperature stress at 4 °C for 24 h. Using high-throughput molecular sequencing technology, a transcriptome sequencing of the leaves was performed at 0, 6, 12, and 18 h of cold stress. Fifteen candidate aquaporin genes in C. bungei (CbAQP) were identified. Phylogenetic analysis showed that the CbAQP gene family is divided into five subfamilies: 5 PIPs, 4 TIPs, 3 NIPs, 2 SIPs, and 1 XIP. By analyzing AQPs related to cold stress in other plants and the expression patterns of CbAQP genes, 12 CbAQP genes related to cold stress were identified. The genes that responded positively include CbPIP2;5, CbPIP1;2, CbTIP4;1, and CbNIP2;1. The results provide a foundation for further analysis of the biological functions of candidate CbAQP genes related to cold tolerance and offer theoretical support for improving seedling quality, cold-resistant genetic breeding, and expanding its distribution range. [ABSTRACT FROM AUTHOR]