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The cultivation of sunflower (Helianthus annuus L.) as a cut flower stands out in floriculture due to its aesthetic beauty and commercial value. Understanding how cut sunflower genotypes adapt to different edaphoclimatic regions and management practices is essential to optimize flower quality and productivity. This study aimed to evaluate the effect of plant density and location on the development, growth, and quality of cut sunflower in tropical and subtropical environments. Plant densities of 10, 20, 30, 40, and 50 plants/m2 were evaluated in tropical climate and subtropical climate using a randomized block design in a factorial scheme. Results showed significant differences between locations for plant height, capitulum and stem diameter, final number of leaves, leaf area, leaf area index, phyllochron, and the developmental cycle. Plant density significantly influenced these variables except for plant height and developmental cycle. The interaction between location and plant density was significant only for capitulum diameter and final leaf number. The findings indicate that both planting density and location significantly influence the developmental cycle of cut sunflowers, with lower densities favoring more robust plants at harvest. A density of 30 plants/m2 is recommended for efficient space use without significantly compromising floral stem quality. All produced stems are marketable, suggesting that adjusting planting density can optimize production without compromising quality, adapting to specific regional conditions. [ABSTRACT FROM AUTHOR]

Planting geometry is one of the most important management practices that determine plant growth and yield of corn. The effects of eight planting geometries (35 × 23 cm, 40 × 21 cm, 45 × 19 cm, 50 × 18 cm, 55 × 17 cm, 60 × 16 cm, 65 × 15 cm, 70 × 15 cm) on plant growth and yields of three sweet corn hybrids (Argos F1, Challenger F1, Khan F1) were investigated under Erzurum, Türkiye conditions in 2022 and 2023 years. Variance analysis of the main factors shows a highly significant effect on whole traits but in two-way interactions some of the traits were significant and in the three-way interactions, it was insignificant. As an average of years, the number of plants per hectare at the harvest varied between 92,307 (35 × 23 cm) and 120,444 (70 × 15 cm) according to the planting geometries. The highest marketable ear number per hectare (107,456), marketable ear yield (24,887 kg ha−1), and fresh kernel yield (19,493 kg ha−1) were obtained from the 40 × 21 cm planting geometry. The results showed that the variety Khan F1 grown at 40 × 21 cm planting geometry obtained the highest marketable ear number (112,472), marketable ear yield (29,788 kg ha−1), and fresh kernel yield (22,432 kg ha−1). The plant density was positively correlated with marketable ear number (r = 0.904 **), marketable ear yield (r = 0.853 **), and fresh kernel yield (r = 0.801 **). The differences among the varieties were significant for the studied traits, except for plant density and kernel number per ear. In conclusion, the variety Khan F1 should be grown at the 40 × 21 cm planting geometry to maximize yields under study area conditions without water and nutrient limitations. [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Produksi Tanaman is the property of Brawijaya University 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.)

Plant responses to multiple environmental conditions in the habitat are characterized by intra-species variety. Ferula assa-foetida L. is a native medical plant in Iran, which has a wide range of therapeutic and pharmacological properties. The objective of the current study was to identify changes in phenolic content, antioxidant capacity and essential oil (EO) composition in different tissues (leaf, flower and fruit) of three populations of F. assa-foetida L. (Sarbisheh, Nehbandan, located in South Khorasan province of Iran). The results showed that total phenolic content (TPC), total flavonoid content (TFC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity in the leaves of Sarbisheh were higher than in other treatments. The amount of TPC, TFC and DPPH scavenging activity in leaves was higher than in other tissues in the Sarbisheh population, increasing by 31 and 70%, 41 and 20%, 8 and 13%, respectively, over that of flowers and fruits. The main EO compounds of leaves were α -pinene (11.86–13.56%), β -pinene (6.80–7.99%), bornyl acetate (15.80–17.33%). The main EO constitutes of flowers were Z-propenyl-sec-butyldisulfide (10.12–12.4%), eco-fenchyl acetate (10.87–12.4%), myrcisticin (13.43–15.87%) and α -bisabolol (11.23–13.76%). The primary compounds of fruit EO were β -pinene (9.32–11.26%), (Z)-1-propenyl sec butyldisulf (17.54–18.87%) and (E)-1-propenyl sec butyldisulf (28.32–30.02%). The agglomerative hierarchical clustering showed that three distinguished clusters were identified for population, where Nehbandan and Qaen had the higher similarity and Sarbisheh completely differed from the two ones. Different plant tissues contain varying types of chemicals, with leaves exhibiting higher levels of phenolic content and antioxidant capacity. This characteristic can be beneficial for industries such as food and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Copyright of La Granja, de Ciencias de la Vida is the property of Universidad Politecnica Salesiana 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 aim of this study was to evaluate the agronomic performance of sorghum grown in different combinations of row spacing and plant density, as well as possible interferences on silage quality. No other study dedicated to identifying the interference of plant spatial arrangement on the cultivation of silage material has been developed in the productive context of the Amazon Biome, making it necessary to understand the behavior of the studied factors. The treatments were arranged in a split-plot scheme: the plots corresponded to three row spacings (0.45 m, 0.60 m, and 0.75 m) and subplots at four densities (105,000, 120,000, 135,000, and 150,000 plants ha−1). The agronomic and productivity characteristics of sorghum and the fermentative and bromatological characteristics of forage and silage were evaluated. The sorghum plants showed an increase in plant height and green and dry mass yield when using higher densities (p < 0.05). For the culm diameter variable, an isolated effect of the factors was observed, with reduced diameter when grown closer to inter-row spacing or using higher plant densities. No effect of the factors was found (p > 0.05) for morphological plant components. In silage, wider spacing promoted higher dry matter content. Regarding crude protein in the silage, higher percentages were obtained at closer spacing and higher plant density. The sorghum growing in dense conditions is indicated, given the positive performance in productivity and bromatological composition. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) 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.)

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.)

Copyright of Indonesian Journal of Agricultural Sciences / Jurnal Ilmu Pertanian Indonesia is the property of IPB University 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 biogas supply chain requires a correct combination of crops to maximize the methane yield per hectare. Field trials were carried out in North Italy over three growing seasons, according to a factorial combination of four cropping systems (maize as a sole-crop or after hybrid barley, triticale and wheat) and two maize plant densities (standard, 7.5 plants m−2 and high, 10 plants m−2) with the plants harvested as whole-crop silage. The specific methane production per ton was measured through the biochemical methane potential (BMP) method, while the methane yield per hectare was calculated on the basis of the BMP results and considering the biomass yield. The average methane yield of wheat resulted to be equal to 4550 Nm3 ha−1, and +17% and +28% higher than triticale and barley, respectively, according to the biomass yield. A delay in maize sowing reduced the yield potential of this crop; the biomass of maize grown after barley, triticale and wheat was 20%, 33% and 47% lower, respectively, than maize cultivated as a single crop. The high plant population increased the biomass yield in the sole-crop maize (+23%) and in the maize grown after barley (+20%), compared to the standard density. The highest biomass (32 t ha−1 DM) and methane yield (9971 Nm3 ha−1) within the cropping systems were obtained for barley followed by maize at a high plant density. This cropping system increased the methane yield by 46% and 18%, respectively, compared to the sole-crop maize or maize after triticale at a standard density. The smaller amount of available solar radiation, resulting from the later sowing of maize, reduced the advantage related to the application of a high plant density. [ABSTRACT FROM AUTHOR]

Tef is a small-seeded staple crop endemic to Ethiopia. However, its yield is low, constrained partly due to improper agronomic practices and lodging. Thus, during the 2019-2020 cropping season, a field experiment was carried out at Reef Tokko Taanne Hamilee in Hababo Guduru district, Western Ethiopia to examine the effects of seed rate and inter-row spacing on growth, phenology, yield, and lodging severity of tef crop. Three levels of seed rates (10, 15, and 20 kg ha-1) and three styles of row spacing (10, 15, and 20 cm) were combined in a factorial combination in a randomized block design with three replications.Tef variety called 'Guduru' was used as planting material. The result showed that seed rate and inter-row spacing had significant (p < 0.01) effects on all phenological and yield-related characteristics studied. Moreover, days to heading, days to maturity, grain yield and harvest index were significantly affected by the interaction effects of both seed rate and interrow spacing. Higher days to heading (68 days) and days to maturity (127 days) were recorded at a seeding rate of 20 kg ha-1 and10 cm inter-row spacing. Tef variety (Guduru) was taller (127.2 cm) under 10 kg ha-1 seed rate as compared to a higher seed rate of 20 kg ha-1 (120.8 cm). The highest dry biomass yield (51.3 kg plot-1) was obtained from a seeding rate of 20 kg ha-1 in combination with 20 cm inter-row spacing. Besides this, the maximum mean grain yield (19.8 kg plot-1) was recorded from 20 kg ha-1 seed rate and 15 cm inter-row spacing to achieve a higher yield in the study area. Furthermore, the highest straw yield (35.99 kg plot-1) was produced from the highest seed rate of 20 kg ha-1, whereas the smallest inter-row spacing (10 cm) produced the highest straw yield (33.5 kg plot-1). The maximum harvest index (56.1%) was obtained from 20 kg ha-1 seed rate and 15 cm inter-row spacing, a similar treatment combination as in the case of grain yield. 10 kg ha-1 seed rate and 20 cm inter-row spacing showed lowest lodging severity (24.1%) and (32.3%), respectively. The result suggests that sowing of tef at 20 kg ha-1 seed rate combined with 10 cm inter-row spacing which resulted in higher grain yield, straw yield and harvest index, could be recommended in the study area to achieve higher tef production. [ABSTRACT FROM AUTHOR]

Population size is a crucial parameter for both ecological research and conservation planning. When individuals are aggregated, estimating the size of a population through sampling raises methodological challenges, as the high variance between sampling units leads to imprecise estimates. Choosing the right sample design depending on the population aggregation level could improve the precision of estimates; however, this is difficult because studies comparing sample designs for aggregated populations have been limited to a few populations and sampling designs, so their results cannot be generalised.To address this gap, we combined simulations of spatial point populations and field counts of three plant species to compare the relative precision of estimates between three sampling methods: simple random sampling (SRS), systematic sampling (SYS) and spatially balanced sampling (SBS). Comparisons were performed on density and aggregation gradients for a range of sample sizes.Our simulations showed that SYS and SBS were always more precise than SRS when individuals were aggregated, reducing sampling variance up to 80% and 60%. The highest precision for estimating population size was always obtained when the average distance between sampling units equalled the diameter of the clusters (i.e. the groups of individuals). The difference in precision was similar for the natural populations, with sampling variance lowered by up to 75% (SYS) and 60% (SBS) compared to SRS.These findings lead us to recommend using SYS or SBS rather than SRS to estimate population size when individuals are spatially aggregated, as these consistently provide more precise estimates. Assessing cluster diameters in the field enables a quick assessment of the potential gain in precision to expect, and thus the best choice of sampling method depending on the trade‐off between precision and field constraints. [ABSTRACT FROM AUTHOR]

Tomato is an important field crop, and nutritional imbalances frequently reduce its yield. Diagnosis and Recommendation Integrated System (DRIS), uses ratios for nutrient deficiency diagnosis instead of absolute concentration in plant tests. In this study, local DRIS norms for the field tomatoes were established and the nutrient(s) limiting tomatoes yield were determined. Tomato leaves were analyzed for nutrients, to identify nutritional status using the DRIS approach. One hundred tomatoes fields were selected from Chatter Plain Khyber Pakhtunkhwa and the Sheikupura Punjab Pakistan. The first fully matured leaf was sampled, rinsed, dried and ground for analyzing P, K, Ca, Mg, Cu, Fe, Mn and Zn using an Inductively Coupled Plasma Atomic Emission Spectrophotometer (ICP AES). Plant tissue N and S were measured by the combustion method. The tomatoes yields were recorded at each location. The data were divided into high-yielding (≥3.79 kg/10 plant) and low-yielding (<3.79 kg/10 plant) populations and norms were computed using standard DRIS procedures. High-yielding plant population had a statistically greater mean S and Fe than the low-yielding population. The average balance index, the sum of functions, for S and Fe were -11.04 and -5.17 which reflected deficiency of S and Fe. Plant nutrients norms established may optimize plant nutrition in field tomatoes for high yield. [ABSTRACT FROM AUTHOR]

In this paper, a mathematical model is applied to investigate the effect of density of allelochemicals on plant population involving delay. The model is constructed using a system of nonlinear delay differential equations. In the model, there are three state variables: plant populations (P1 & P2) and density of allelochemical (T). It is assumed that in the presence of density of allelochemicals, plant populations are affected. It further delays the conversion of resource into the density of allelochemicals and hence affects the plant population adversely. This effect is observed by using delay in the competition model. Equilibrium points are calculated. Using the Routh–Hurwitz theorem, certain explicit formulations defining the stability and path of the Hopf‐bifurcation periodic solutions at the positive equilibrium are obtained. Further, the direction of these bifurcating periodic solutions is also studied. Numerical simulation and graphical support are provided for analytical findings using MATLAB. [ABSTRACT FROM AUTHOR]

Background: Soil microbiome is an important part of the forest ecosystem and participates in forest ecological restoration and reconstruction. Niche differentiation with respect to resources is a prominent hypothesis to account for the maintenance of species diversity in forest ecosystems. Resource-based niche differentiation has driven ecological specialization. Plants influence soil microbial diversity and distribution by affecting the soil environment. However, with the change in plant population type, whether the distribution of soil microbes is random or follows an ecologically specialized manner remains to be further studied. We characterized the soil microbiome (bacteria and fungi) in different plant populations to assess the effects of phytophysiognomy on the distribution patterns of soil microbial communities in a temperate forest in China. Results: Our results showed that the distribution of most soil microbes in different types of plant populations is not random but specialized in these temperate forests. The distribution patterns of bacteria and fungi were related to the composition of plant communities. Fungal species (32%) showed higher specialization than bacterial species (15%) for different types of plant populations. Light was the main driving factor of the fungal community, and soil physicochemical factors were the main driving factor of the bacterial community. Conclusion: These findings suggest that ecological specialization is important in maintaining local diversity in soil microbial communities in this forest. Fungi are more specialized than bacteria in the face of changes in plant population types. Changes in plant community composition could have important effects on soil microbial communities by potentially influencing the stability and stress resistance of forest ecosystems. [ABSTRACT FROM AUTHOR]

The effect of agronomic factors on the amount of water consumption and its productivity in arid and semiarid regions is very important. This study was conducted to diagnose agronomical procedures for increasing the yield and water productivity of sugar beet in two years (2016 and 2017). The experimental factors were: sowing date (spring and summer), planting arrangement (25-50 cm and 40-50 cm, double rows with a distance of 25 cm or 40 cm and a distance between each double row of 50 cm), and plant density (90, 120 and 160 thousand plant/ha). In the second year, the harvesting date, which consisted of conventional (October) and delayed (November), was added to the experiment. High temperature during and immediately after planting decreased emergence on the summer sowing date. The uniformity of roots and irrigation water productivity (WPirrig) in spring crops was higher than those of summer crops; meanwhile, on the summer sowing date, water consumption declined by 27% (and the sugar yield decreased intensively by 44%). Furthermore, planting arrangements of 25-50 resulted in better plant establishment and eventually increased the number of final plants. Besides, increasing plant density improved the uniformity of plants root. Sowing in summer compared to spring reduced root and sugar yield on a conventional harvesting date by about 40%. After 25 days' delay in harvesting time on both sowing dates (by mean), root yield, sugar yield, and WPirrig, increased by about 14, 28 and 22%, respectively. In general, at moderate densities (about 120 000), planting arrangement 40-50 and at low densities (less than 90 000, which usually occurs on the summer sowing date), planting arrangement 25-50 is recommended to increase yield and WPirrig. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos de Ciências Veterinárias e Zoologia da Unipar is the property of Associacao Paranaense de Ensino e Cultura 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.)

Row crops normally grown in Southeast USA are cotton (Gossypium hirsutum L.), corn (Zea mays L.), and peanut (Arachis hypogea L.) with a focus on the higher economic value for peanut. Peanut is typically planted using a twin-row pattern and purchasing a twin-row planter may not be cost effective unless used with other rotational crops. The objectives were to compare corn yield when planted in twin-rows, with two plant densities, at multiple locations, and irrigated with drip or sprinkler system. Corn was planted in single and twin-row patterns at 7.9 seeds/m (normal; 86,100 seeds/ha) and 4.9 seeds/m (half-normal; 53,600 seeds/ha) at multiple locations and cropping seasons. Irrigation systems consisted of subsurface drip (SSDI), shallow subsurface drip (S3DI) and overhead sprinkler. Single and twin-row with normal seeding rate had same yield across years, locations, or irrigation system 88% of the time. With drip irrigation only, twin-row half-normal seeding rate had the same yield as the single-row normal seeding rate 75% of the time and when factoring in seed savings had an economic benefit of $56/ha. The single-row half-normal seeding rate always had lower yield compared with other treatments. The S3DI irrigation system had greater yield than SSDI for both row patterns and seeding rates. Therefore, a twin-row planter purchased for peanut may be used to plant corn without yield reduction using normal seeding rates under either drip or sprinkler irrigation systems. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess yield components and grain yield of soybean cultivars in response to sowing densities. For this, two soybean cultivars and five sowing densities were tested, in a two-factor scheme. The following yield components were measured by the end of the cycle: plant height; insertion height of the first pod; number of nodes per plant; number of pods with one, two, three and four grains; number of pods per plant; number of grains per plant; weight of a thousand grains; humidity and grain yield. Sowing densities did not cause significant variations of grain yield (bags ha-1) for any cultivar, however, higher populational densities promoted a reduction in the number of pods with two and three grains, as well as a reduction in the total number of pods and grains per plant for both cultivars. Cultivar NS 5700 IPRO was the most productive, with a higher number of pods with two and three grains and number of pods and grains per plant. [ABSTRACT FROM AUTHOR]

Occupancy models have been underused in multispecies plant studies. We evaluated the effectiveness of occupancy models to document impacts of management on grassland plant species populations in a pilot study. The study was designed to answer three questions: (1) From a list of 44 plant species, how many will have sufficient frequency to be analyzed? (2) Within a single site, which factor (sampling year or unit) influences occupancy and detection of each plant species? (3) How does the number of plots and visits affect the number of species with sufficient frequency for analysis? In 2012 and 2013, occupancy and detection probabilities of 44 plant species were assessed using permanently marked plots on two different grassland sites. Within each site, a fire and grazing managed unit and a burn‐only control unit were used to test the efficacy of occupancy modeling for multiple plant species and study design. Four of the 44 species had sufficiently high known presence (π) on both sites and years to be analyzed. There was little evidence to support that occupancy was different between years, despite very different weather patterns. There was support that occupancy was different in the burned and grazed unit compared with the control for Rhus copallinum L. Detection was highest (≥0.8) for R. copallinum, while the other species analyzed varied. In 2012, eight species had sufficient π for analysis. In 2013, 12 species had sufficient π for analysis. Occupancy models can be useful for investigating multiple plant species; however, a priori investigation of species' distribution is necessary to ensure species can be analyzed. Detection of plants was never 1, and therefore, detection should continue to be incorporated in plant population models, regardless of modeling technique. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) stem density variation in the field can be used to inform harvest timing to improve tuber size distribution. Current methods for quantifying stem density are manual with low throughput. This study examined the use of Unmanned Aerial Vehicle imagery as a high-throughput alternative. A colour-based feature extraction technique and a deep convolutional neural network (CNN) were compared for their effectiveness in enumerating apical meristems as a proxy to subtending stems. Two novel colour indices, named the cumulative blue differences index and blue difference normalized index, showed significant differences (P < 0.001) between meristematic leaves and mature leaves in comparison to other indices. The two indices were used to generate 500 pseudo-labelled human-corrected images as training data for the CNN. Benchmarked against a human labelled test dataset, the CNN performed better with a normalized Root Mean Square Error (nRMSE) of 0.09 than the sole use of the image analysis algorithm (nRMSE = 0.3) in predicting the number of meristems in a canopy at 52 days after planting. Furthermore, the CNN had better precision (Intersection over Union [IOU]: 0.49 and 0.56, respectively) than the image analysis algorithm (IOU: 0.33 and 0.13, respectively). Meristem counts in both approaches showed a linear relationship with actual subtending stem counts (P < 0.001). This study demonstrates the validity of using traditional image analysis and CNNs to generate meristem detectors with acceptable nRMSE. Transfer learning with CNN is proposed for developing meristem detectors for evaluating stem density variation from UAV images in the field. [ABSTRACT FROM AUTHOR]

Background: Peanut yields are affected by plant density and chemical controls. Methods: A field experiment was conducted in Southern China to investigate the effects of population density and paclobutrazol applications on the growth and yield of peanuts with monoseeding and double seeding patterns. Result: Paclobutrazol application could improve peanut yields. The highest peanut yields were observed with 250 mg L-1 paclobutrazol and a plant density of 235 410 plants ha-1, with the monoseeding pattern. Our results suggest that monoseeding and paclobutrazol could be applied to enhance peanut yields in Southern China. [ABSTRACT FROM AUTHOR]

The field experiments were conducted at Indonesian Vegetable Research Institute (IVEGRI) West Java, Indonesia during the period of July 2018 to February 2019. The objective of the study was to determine the effect of three plant densities (20,000, 30,000 and 40,000 plants ha-1 ) and four stem pruning levels (control, 3 stems, 4 stems, and shoot pruning) on growth and yield parameters as well as pest and diseases incidences for chili pepper. Split plot experiment was performed using a randomized block design with three replications. The recommended cultural practices were done for better crop growth and good yields. Results showed no interactions between plant density and pruning for any of the variables measured. Chili pepper growth, yield, and quality and incidence of pest and diseases can be effectively manipulated by plant density and pruning. Increasing of plant population from 20,000 to 30,000 plants ha1 resulted in the increased of total fruit yield to 52.58%, however, total fruit yield declined up to 34.09% at 40,000 plant/ha. Pruning significantly affected fruit yield from 4.65 to 20.33%. Shoot pruning produced higher number of branches, and resulted in maximum yield per ha-1 due to higher number of shoots contributing to the production of more number of fruits. Growing chili pepper at a density of 30,000 plant ha-1 was better than the conventional methods, and it combination with shoot pruning in nurseries could be used as an alternative method to increase the production of chili pepper. [ABSTRACT FROM AUTHOR]

Camelina (Camelina sativa L. Crantz), has gained considerable attention in Europe as a potential oil seed feedstock for biofuels and bioproducts, although as cultivated surfaces it remains a marginal crop. As well in Romania progress has been made towards camelina's yield potential but this under organic agriculture conditions has not been studied enough. Given this increased interest in camelina, six genotypes were compared to characterize camelina's production potential in organic farming. Field experiments were conducted out in a randomized complete block design (RCBD) with four replications, six genotypes in three growing seasons (2016-2019). Plant population, frequency (F%) of downy mildew attack, weeds infestation and yield were evaluated. The higher amount of spring rainfall (in 2017 and 2019) and cooler temperatures favoured a significant downy mildew plant infection, with some variations among genotypes. GP 202 proved to be most sensitive to downy mildew attack followed by Lena. The most resistant genotype was Calena, which recorded, for the three different years, the lowest degree of attack. In weeds suppression the variation due to year was higher than that due to the genotype and interactions of the factors. Results identify, in relation to climatic conditions, the most suitable genotypes for the tested environment, in terms of resistance to downy mildew and weed infestation. Calena, Camelia and Lindo genotypes were more less affected by downy mildew, weed infestation was less and the yield was higher as compared to the other genotypes studied. [ABSTRACT FROM AUTHOR]

Plant population of 40,000 ha−1 with the respective inter- and intra-row spacing of 50 cm × 50 cm is the blanket recommendation for the production of head cabbage in Ethiopia. However, producers complain that this spacing produces too large head size, which is not the market's preference for household consumption instead for hotels and big institutions like universities. This twoseason field experiment was conducted to optimize the head cabbage yield with appropriate head size by adjusting inter- and intra-row spacing. The result of the combined analysis over location and season revealed that all tested parameters were significantly (P < 0.05) influenced by the interaction effect of inter- and intra-row spacing. The combinations of 35 cm × 30 cm, 35 cm × 50 cm, and 50 cm × 30 cm inter- and intra-row spacing gave the highest head yield of 45, 43 significantly, and 42 t ha−1 , respectively as compared to other treatment combinations. The interaction of the lowest inter- and intra-row spacing of 35 cm × 30 cm gave the lowest average head weight of 923 g of cabbage. The result showed that as intra-row spacing increased from 30 to 50 cm with all possible combinations of inter-row spacing, head-sized cabbage increased linearly. The current study identified that blanket recommendation of 50 cm × 50 cm inter-and intra-row spacing which assures a plant population of 40,000 ha−1 produced more than 1.4 kg individual head weight with a yield penalty of 10.70 t ha−1 compared to 50 cm × 30 cm inter- and intra-row spacing combination which assures a plant population of 66,667 ha−1 . The current study confirmed that the earlier blanket recommendation of 40,000 plants ha−1 should be enhanced to a plant population of 66,667 ha−1 with a yield advantage of 131%. Concretely the manifested plant population difference gives an opportunity to producers to harvest a maximum yield with an acceptable head size of 1.2 kg. Therefore, it is concluded that the combination of 50 cm × 30 cm inter- and intra-row spacing assures that a plant population of 66,667 ha−1 is optimum for the production of head cabbage in the study and similar agroecologies. [ABSTRACT FROM AUTHOR]

Copyright of Temas Agrarios is the property of Universidad de Cordoba 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.)

Increases in plant density associated with the use of plant growth regulators, aside from modifying the plant architecture, can also change the maize yield performance. This study aims to investigate the yield components and grain yield of maize hybrids with contrasting leaf architecture, in response to different plant populations and trinexapacethyl rates (TE). Field experiments were conducted in two growing seasons, in a (5 x 5) factorial randomized block design. The treatments consisted of: five plant population (40, 60, 80, 100, and 120 thousand plants ha-1) and five TE rates (0, 100, 200, 300, and 400 g a.i. ha-1), with four replications, using the hybrids 2B710 HX and Status TL. We evaluated the number of rows per ear, ear length, number of grains per row, 1000-grain mass, and yield. An increased plant density reduces ear length, number of grains per row and 1000-grain mass, without changing the number of grain rows per ear. TE rates increases ear length and number of grains per row and reduces 1000-grain mass, mainly under favorable cultivation conditions. TE interacts with the plant density, changing the maize yield components with increases in grain yield, but these gains variy, according to the environment and genotype characteristics. [ABSTRACT FROM AUTHOR]

The study of the structure and dynamics of vegetation was carried out in the ecosystems of southern Benoue in northern Cameroon. The general objective of this work is to characterize the structure of the vegetation and to assess the degradation of the ecosystems. The inventory methods chosen include biodiversity survey techniques commonly used in ecological studies. A total of 36 100 m x 100 m quadrat plots were established in four plant formation: reserve, forest gallery, field and anthropized savanna to take dendrometric parameters such as size, diameter at breast height of all woody species. Landsat satellite images were processed and analyzed between 1989 and 2019 using Google Earth and GIS software, QGIS 10.12.1.The vegetation presents a physiognomy of open forest with a diametral L-shaped structure reflecting the dominance of individuals of small DBH and a vertical "U" structure reversed from sites and plant formations reflecting a low representation of juvenile and adult individuals. As for the diachronic study by remote sensing, it emerges from the variations of land use elements an increase in field (by 29%, 10% and 20%), of the grassy savannah (by 2%, 14% and 8 %) and buildings and bare soil (by 5%, 8% and 2%) and a decrease in shrub savannah (by -31%, -23% and -14%), in wooded savannah (by -2%), -5% and -12%) and gallery forest (-4%, -5% and -4%) respectively for Garoua 3, Lagdo and Ngong. Overall, our zone is marked by an accentuated state of degradation of the vegetation with a current state of cover of the grassy savanna of 38%, of the field of 28%, of the shrub savannah of 16%, of the wooded savanna and the frame and bare floors of 7% each, the forest gallery of 5% and the open water of 4%.These results open up better prospects for the development of planning and development mechanisms of this area not yet deeply explored for the bases of a good management strategy. [ABSTRACT FROM AUTHOR]

Turmeric (Curcuma longa L.) is largely used in diversified forms as a condiment, flavouring and colouring agent and as a principal ingredient in Indian culinary as curry powder. For the higher productivity, identification of location specific production technologies is of prime importance. A study was conducted at the Department of Agronomy, Punjab Agricultural University, Ludhiana, Punjab for three consecutive years during kharif seasons of 2013-2015 to appraise the effect of planting methods and plant population on growth and yield of turmeric, and physical properties of the soil. The experiment was arranged in split plot design with four planting methods viz., flatbed, ridge spaced at 45 cm, ridge spaced at 60 cm and bed of 67.5 cm (2 rows per bed) in main plots and three plant populations viz., 1,33,334; 1,66,667 and 2,00,000 plants ha-1 in sub plots with four replications. The results revealed that bed (67.5 cm) planting method registered significantly better growth and yield attributes like plant height, leaf area index, dry matter accumulation, number of rhizomes per plant and consequently fresh and dry rhizome yields than other planting methods except than flatbed during first year. Plant height and leaf area index were significantly improved while dry matter accumulation and number of rhizomes per plant were significantly less with higher plant population than lower plant population. Fresh and dry rhizome yield were significantly higher with plant population of 2,00,000 and 1,66,667 plants ha-1 than plant population of 1,33,334 plants ha-1 due to more plants per unit area under higher plant population. Soil bulk density was significantly lowered under ridge and bed planting methods than flatbed planting method at shallow (0-15 and 15-30 cm) soil layers, however, no significant effect was observed at deeper soil layers of 30-45 and 45-60 cm. Water infiltration rate was recorded in the lessening order of ridge spaced at 60 and 45 cm, bed 67.5 cm and flatbed planting methods, respectively. [ABSTRACT FROM AUTHOR]

Reducing the leaf senescence rate could improve the grain yield in maize. In the present study, maize seeds were treated with uniconazole at concentrations of 0 and 25 mg kg-1, and nitrogen was applied at 0, 150, and 225 kg ha-1 to maize crop planted at a density of 105,000 plants ha-1. Applying uniconazole and nitrogen reduced the leaf senescence rate by increasing the leaf area per plant, chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate. Uniconazole and nitrogen increased the electron transport rate, photochemical quenching coefficient, variable fluorescence, maximal quantum yield of PSII photochemistry, and effective quantum yield of PSII photochemistry. Uniconazole and nitrogen reduced the intercellular carbon dioxide concentration, nonphotochemical quenching coefficient, and malondialdehyde content but increased the soluble protein content and antioxidant enzyme activities. Applying uniconazole at a concentration of 25 mg kg-1 and nitrogen at a rate of 150 kg ha-1 obtained the maximum grain yield in maize. [ABSTRACT FROM AUTHOR]

Plant arrangements are a practice that has remained constant for decades, with little research about soybeans, with contrasting rainfall conditions. The purpose of this work was to evaluate the agronomic performance of indeterminate soybean with variation for the plant arrangements, populations and in cultivation of crops. The research was conducted in Arapongas-PR with an experimental design of randomized blocks, organized in a 6x3x2 factorial scheme, with four replications. The variation factors were six populations (100, 200, 300, 400, 500 and 600 thousand plants ha-1), three plant arrangements (0.25 cm, 0.50 cm and 0.25x0.50 cm in paired-rows) and two cultivation of crops. The statistical analysis sought to evaluate the interactions and break down the simple effects and the main effects. Row spacing influenced the variables grain yield, height of the first pod insertion, plant height and leaf area index. Populations with up to 300 thousand plants reached the highest levels of grain yield. The plant arrangement for the paired-rows is superior to traditional spacing, with 4,732 kg ha-1 for the spacing 0.25x0.50 m, 3,817 kg ha-1 for the spacing 0.50 m and 3,628 kg ha-1 for the spacing 0.25 m. [ABSTRACT FROM AUTHOR]

Chicken weed is a significant weed in India and it occurs under onion cultivated field at Birnin Kebbi in the Sudan Savannah, Nigeria. On-farm experiment was conducted at Birnin Kebbi during the 2017/2018 and 2018/2019 dry season to evaluate the effect of plant population and weed control methods on the management of chicken weed (Portulaca quadrifida) alongside other weeds in onion field. The experiment consisted of three plant populations (500,000, 333,333 and 250,000 plants per hectare) and twelve weed control methods (Pendimethalin at 1.0 kg a.i. ha-1, + 1Hw; pendimethalin at 1.5 kg a.i. ha-1 + fluazifop-p-butyl at 2.0 kg a.i. ha-1; pendimethalin at 2.0 kg a.i. ha-1; butachlor at 2.0 kg a.i. ha-1 + 1Hw; butachlor at 2.8 kg a.i. ha-1 + oxyfluorfen at 1.0 kg a.i. ha-1; butachlor at 3.6 kg a.i. ha-1; fluazifop-p-butyl at 2.0 kg a.i. ha-1; oxyfluorfen at 1.0 kg a.i. ha-1 + 1Hw; hoe weeding at 3 (WAT); hoe weeding at 3 and 6 WAT; weed free and weedy check). The experiment was laid out in a randomized complete Block design replicated three times. Results showed that weed, growth and yield parameters were not significantly affected by plant population. Pendimethalin at 1.5 kg a.i. ha-1 + fluazifop-p-butyl at 2.0 kg a.i. ha-1 and weed free plots consistently recorded the lowest weed cover and highest weed control efficiency. Butachlor at 2.0 kg a.i. ha-1 + 1 Hw recorded the lowest crop injury score. Increase in plant height was observed when pendimethalin at 1.0 and 1.5 kg a.i. ha-1 + 1 Hw and fluazifop-p-butyl at 2.0 kg a.i. ha-1 respectively was applied, while application of pendimethalin at 2.0 kg a.i. ha-1 and butachlor at 2.0 kg a.i. ha-1 + 1 Hw recorded highest number of leaves and leaf area. Cured bulb and marketable bulb yield were greater with the use of pendimethalin and butachlor at 1.0 and 1.5 kg a.i. ha-1 + 1 Hw and the pooled data respectively. Application of pendimethalin and butachlor at the rate of 1.0 and 2.0 kg a.i. ha-1 followed by 1 Hw at 6 WAT respectively was therefore recommended for the control of chicken weed alongside other weed species in the ecology. [ABSTRACT FROM AUTHOR]

Plastic mulches have been extensively used in tomato fields around the world; its use has been growing in Brazil, especially in semi-arid regions. However, whether plastic mulches are beneficial to tomato grown in the Brazilian semi-arid and should replace other traditionally used practices is little known. Two on-farm experiments were carried out aiming at assessing the yield response of 'Trucker' hybrid tomato to plastic mulching in interaction with other practices, viz, irrigation, earthing up, and plant population. The first experiment consisted of a randomized block design with six treatments arranged in a 3 x 2 factorial and replicated four times: three crop practices (earthing up, plastic mulching and bare soil) combined with two plant populations (12,500 and 10,416 plants ha-1). The second experiment was a randomized complete block design with four replications, in a splitplot arrangement. Irrigation levels (305, 440, 495, 610 and 725 mm cycle-1) were assigned to plots, and mulching and earthing up to subplots. Fruit diameter, fruit weight and crop yield were evaluated. Plastic mulching had no effect on crop yields and water-use efficiency at both experiments. Overall, the results suggest planting 'Trucker' tomato at 12,500 plants ha-1, 580-630 mm cycle-1 of irrigation, and without plastic mulching. [ABSTRACT FROM AUTHOR]

Chamomile is an important socioeconomic option for family farming. Its cultivation involves manual management practices and herbicide use restriction, and knowledge regarding weed interference on the yield of chamomile capitula and essential oil quality is still limited. In this perspective, this study aimed to assess the effect of sowing dates, plant spacings, and hoeing management on the yield of chamomile capitula, essential oil yield, and essential oil content under the environmental conditions of a region with a Humid Subtropical climate without defined seasons. The experiments were conducted on four dates (March 18, March 28, June 31, and August 30, 2017, with plants spaced 0.05, 0.10, 0.15, 0.20, 0.30, and 0.40 m within rows. On March 28 and May 14, 2018, the spacings between plants in the row were 0.05, 0.10, 0.15, and 0.20 m, including two hoeing managements (with and without weeds). The variables analyzed in the two years were the yield of dry capitula, the dry mass of chamomile plants and weeds (g m-²), and the content and yield of essential oil in 2018. The sowing dates influenced the yield of floral capitula, the essential oil content, and the essential oil yield as a function of the duration of the cycle and weed occurrence. The autumn sowings resulted in a higher yield of floral capitula in both years. A linear reduction trend was also verified in the yield of floral capitula with the increase in plant spacing within the row from 0.05 to 0.20 m in the two crop years. [ABSTRACT FROM AUTHOR]

Banana production stands out in Brazilian semiarid agriculture; however, due to little availability of water resources, associating water-saving technologies with the knowledge of parameters involved in the interplay between plants and soil is critical to improving banana production systems. The objectives of this study were to evaluate the effect of planting densities and irrigation levels on root length density of 'BRS Platina' banana and to correlate root parameters to crop yield and leaf area. A randomized block design was used, with factors arranged in split-split plots and treatments replicated three times: four irrigation levels (55%, 70%, 85% and 100% ETc) were assigned to plots, four planting densities (1,600; 2,000; 2,666; and 3,333 plants ha-1) to subplots and distance from pseudostem or sampling depth to sub-subplots. Root length density (RLD) was measured at five distances from the pseudostem, longitudinally to a row of plants: 0.10, 0.25, 0.50, 0.75 and 1.10 m; and at three depths for each distance: 0 to 0.20 m, 0.20 to 0.40 m and 0.40 to 0.60 m from surface level. Root length densities were highest at 100% ETc irrigation level and at 2,666 plants ha-1 and 3,333 plants ha-1, within 0.31 m deep and within 0.78 m of the pseudostem. Irrigation interacts with root system, and coupled with higher planting densities, contributes to increasing crop yields of 'BRS Platina' banana plants. [ABSTRACT FROM AUTHOR]

In this paper, a non-linear mathematical model is proposed and analyzed to study the dynamics of plant-pollinator-pesticide interactions. Analysis of the existence of equilibrium points is done. Sufficient conditions for local as well as global stability have been derived. A threshold value of the energetic reward is obtained above which the dynamical system persists uniformly. Further, numerical simulations are performed to confirm the analytic results and to deduce some other important conclusions. It is shown that the plant and pollinator populations support the growth of each other and are mutually dependent when the energetic reward is sufficiently high. Observations show that equilibrium values of plant and pollinator populations can be maintained for high energetic rewards even though pesticides are present. However, if energetic rewards are low, the presence of pesticides will lead to plant extinction. [ABSTRACT FROM AUTHOR]

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Herbivores are a diverse group of fauna that shape the distribution and composition of plant communities. In some cases, herbivory may prevent the re-establishment of submerged aquatic vegetation (SAV), such as Vallisneria americana, into systems. The goal of this study was to investigate the role and nature of herbivory on V. americana transplants with camera and transect surveys of grazing intensity and with field and laboratory grazing experiments using a suspected herbivore, the blue crab, Callinectes sapidus. Camera surveys recorded C. sapidus clipping and consuming shoots of V. americana for the first time. Grazing intensity surveys in low-salinity regions of the lower Chesapeake Bay indicated that the majority of V. americana transplants (50–75%) were clipped off at their base within one week of planting. Field and laboratory experiments demonstrated that C. sapidus clips and consumes V. americana as well as other rapidly colonizing, non-native SAV. Analysis of the gut contents of C. sapidus caught in SAV beds in the Chesapeake Bay revealed that SAV comprised 16% of their stomach contents, suggesting low levels of C. sapidus herbivory occurred over a wide area. Callinectes sapidus is yet another animal documented to consume SAV for some portion of their diet. These results also suggest that herbivores or omnivores, including C. sapidus, can serve as bottlenecks to recovery of SAV, like V. americana, in some areas. Herbivores may not serve as bottlenecks in other environments or to other SAV with more rapid plant growth or higher recruitment levels that may overcome grazing pressure. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Academic Journal of Biological Sciences, H. Botany is the property of Egyptian Academic Journal of Biological Sciences 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 paper presents the results of the field experiments dedicated to investigation of chickpea reaction on cultivation technology elements in the South of Ukraine. The study was carried out during 2012-2014 on the dark-chestnut soil in the semi-arid climate conditions. The design of the study included research of the crop reaction on the following agrotechnological factors: plowing depth (20-22, 28-30 cm), fertilization dose (N0P0; N45P45; N90P90), plants population (50, 100, 150 plants per m²), and humidification conditions (sprinkler irrigation applied or not). The study was conducted in four replications by the split plot design method with the crop variety Rosanna of Kabuli type. Chickpea yielding data were processed by ANOVA procedure, the differences obtained in the experiments are significant and reliable at the probability level of 95%. The results of the experiments testify that the best crop productivity could be obtained at the irrigated variants with the highest fertilization dosage, the maximum plants population, and plowing at the depth of 28-30 cm - 3600 kg per ha. However, the best water resource use efficiency was obtained at the variants with plowing at the depth of 20-22 cm - 36.66 kg per mm. Absence of water supply by irrigation also worsened the water use efficiency and productivity of the crop. Mineral fertilizers and optimum plants population significantly enhanced the crop water use efficiency and productivity both at the irrigated and non-irrigated conditions. [ABSTRACT FROM AUTHOR]

Copyright of Colloquium Agrariae is the property of Asociacao Prudentina de Educacao e Cultura (APEC) 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.)

Crop growth models including CERES-Maize and CROPGRO-Soybean have been used in the past to evaluate causes of spatial yield variability and to evaluate economic consequences of variable rate prescriptions. In this work, a nitrogen prescription program has been developed that simulates the consequences of different nitrogen prescriptions using the DSSAT crop growth models. The objective of this paper is to describe a site-specific nitrogen prescription and economic optimizer program developed for computing spatially optimum N rates over long periods of weather and plant population for maize (Zea mays L.) using the CERES-Maize model. The application of the model was demonstrated on a field in Germany and another one in the USA to evaluate the concept across different environmental conditions. The user can determine the short- and the long-term optimal spatial nitrogen prescription based on crop price and nitrogen cost. The program simulated short-term optimum N applications that averaged 9% (McGarvey field, USA) and 48% (Riech field, Germany) lower than the uniform rates actually applied in the fields. The program indicated different site-specific N management options for low and high yielding fields under the assumed prices for maize and N. The implementation of a site-specific plant population management was investigated. A site-specific-optimization of plant population showed a higher profitability in the heterogeneous field in Germany. Hard pan depth, hard pan factor, root distribution factor and the percentage of available soil water across the heterogeneous field were useful indicators in predicting the magnitude of site-specific plant population benefits over uniform rates. [ABSTRACT FROM AUTHOR]

The process of improving crop management inputs by use of remote sensing devices is a new technology. This study presents the use of the normalized-difference vegetative index (NDVI) combined with the coefficient of variation (CV) to predict plant populations in corn (Zea mays L.) over different growth stages and different locations. About 76 plots were selected from the two sites to conduct this research. The results showed that we were not able to reliably predict plant population at lately growth stages because the canopy covered the soil with overlapping leaves. However, at early growth stages, the results suggest that as the corn plant emerged from the soil, the biomass per unit area was small and the sensor technology application for prediction of plant population was possible. Further studies may be designed based on this observation to investigate the possibility at early growth stages such as V2 and V3. [ABSTRACT FROM AUTHOR]

In‐row plant densities have not been studied for common beans with type II growth habit and contrasting reactions to white mould. Advanced breeding lines with partial resistance or susceptibility to white mould were combined with 4, 7, 10 or 13 plants m−1 and with or without fungicide at a constant between‐row spacing of 0.5 m in five sprinkler‐irrigated field trials conducted during the autumn–winter season in Brazil. White mould pressures in the trials covered the whole range from zero to moderate/high (46–60% of white mould severity index). In all trials, means of white mould incidence, severity and yield did not vary significantly between 7 and 13 plants m−1 for the partially resistant line, regardless of the fungicide levels. For the susceptible line, 13 plants m−1 increased white mould incidence and severity under moderate disease, regardless of the fungicide levels, and decreased yield compared with 10 plants m−1 when fungicide was applied twice under moderate/high disease pressure. For the susceptible line, 7 or 10 plants m−1 maximized yield in all trials, with or without fungicide applications. The results suggest that the current recommendation of 11–13 plants m−1 could be used for type II beans with partial resistance to white mould in either a conventional or organic system. For susceptible genotypes, 7–10 plants m−1 seems to be the most appropriate in‐row plant density. This study may improve the recommendation of in‐row plant density for type II beans cultivated under white mould pressure. [ABSTRACT FROM AUTHOR]

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Establishing an adequate plant population is one of the first challenges of sugar beet production. Reduced sugar beet emergence results in a decision between a lower than desired plant population or replanting the field. The objective of this study was to determine the plant population that warrants replanting a field to maximize extractable sugar ha-1. The study was conducted in three environments during the 2016 and 2017 growing seasons. Two planting dates and six plant populations were utilized in each environment. The two planting dates were separated by 19 or 20 days to simulate a replant situation. Sugar beets in each planting date were hand thinned to six populations of 44,000, 58,700, 73,400, 88,100, 102,800, and 117,400 plants ha-1. Planting date and plant population did not significantly affect sugar concentration. However, planting date and plant population influenced yield and extractable sugar ha-1. Extractable sugar yieldwas maximized with the first planting date and populations of 102,800 and 117,400 plants ha-1. A population of 58,700 plants ha-1 in the first planting date had similar extractable sugar yield to the second planting date populations of 88,100, 102,800, and 117,400 plants ha-1. Sugar beet populations above 58,700 plants ha-1 should not be replanted based on the results from this study. [ABSTRACT FROM AUTHOR]