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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]

Vinasse is not only effectively used in pest control but also creates a conducive environment for the growth of antagonistic microorganisms. Thus, this study aimed to evaluate the potential of vinasse applied via soil for the management of root-knot nematodes in soybean culture. The experimental design was entirely random, in a factorial scheme (2 × 6), consisting of two species of nematodes, Meloidogyne incognita and M. javanica, under vinasse application at five concentrations (20, 40, 60, 80, and 100%) and one control (water), with five repetitions. Soybean plants Intacta cv. M-Soy 8644 IPRO were inoculated with 4000 eggs/juveniles of each species separately. At 60 days after the first application of vinasse, evaluations of parasitism and agronomic characteristics in soybean were performed. Stillage resulted in the highest average values for root volume and root fresh mass in plants inoculated with M. incognita, showing respective increases of 24.33% and 14.92% compared to plants inoculated with M. javanica. However, concentrations exceeding 60% had a detrimental effect on all agronomic variables of soybean. For parasitism, an interaction among the factors was observed, with a significant effect (p < 0.01) for most of the evaluated variables, except for the number of eggs in the soil. The concentration equivalent to 60% vinasse promoted a sharp reduction in parasitism for the two nematode species, making reproduction on plant roots unfeasible. [ABSTRACT FROM AUTHOR]

Maintaining the plant architecture of Psidium guajava L. (guava tree) is essential for enhancing capture and distribution in the plant, directly affecting the fruit quality. The lifespan of the harvest period can be extended by proper pruning. Both timeliness and proper pruning play crucial roles in achieving high-quality fruit production and in maintaining a consistent fruit size while stimulating ascorbic acid levels, sugar content, total soluble solids (TSS), and titratable acidity. From this perspective, this study aimed to characterize the influence of different intensities of fruit pruning and thinning on guava trees grown under a seasonal tropical climate in two growing seasons in Currais, Piauí, Brazil. The experiment was set up in a randomized block design with a 3 × 3 × 2 factorial arrangement corresponding to short, medium, and long pruning intensities and 0%, 10%, and 20% thinning intensities during the two growth seasons, respectively. An analysis was performed to discriminate the treatment groups according to the physicochemical variables of the guava tree cv. Paluma and canonical discriminant analysis. There was significant variation in the SS, titratable acidity, ascorbic acid, and pH contents. Cluster analysis of all treatments allowed division into five different groups for the two pruning times. Canonical discriminant analysis showed that the first two canonical variables explained 91% of the total variance. The fruits of the second harvest exhibited a lower level of acidity, higher levels of soluble solids, and higher levels of ascorbic acid contents. In addition, these fruits also obtained better nutrient contents. Short pruning with up to 20% thinning, medium pruning with up to 10%, and long pruning without thinning favored better levels of macronutrients and micronutrients and, consequently, better fruit quality. Medium or long pruning with up to 20% thinning resulted in higher average fruit weights and nutrient contents (especially of Fe and Cu), lower acidity, and higher ascorbic acid contents. Thus, in general, the importance of production pruning in guava plants is evidenced and thinning of 20% is recommended to improve the fruit quality. [ABSTRACT FROM AUTHOR]

Weed coexistence with an agricultural crop can negatively affect its growth, development, and yield. From this perspective, this study aimed to evaluate weed management strategies and their effect on the agronomic parameters of cowpea cultivation in direct (SPD) and conventional (SPC) planting systems. The experiment was set up in a completely randomized block design with a split-plot arrangement with four replications. The plots received a source of variation referring to the planting systems (direct and conventional planting), and the subplots corresponded to ten weed management strategies (manual hoeing 18 days after planting (DAP); at 36 DAP; at 54 DAP; at 18 and 36 DAP; at 18 and 54 DAP; at 18 and 72 DAP; at 36 and 54 DAP; at 36–72 DAP; at 18, 36, and 54 DAP; and a control with no hoeing). Density and dry mass evaluations of the cowpea plants were performed at harvest (72 DAP) by determining the number of pods per plant, pod length, number of grains per pod, 1000-grain mass, and yield. A total of 28 species distributed in 12 botanical families were identified in the two cultivation systems. The family Poaceae showed the highest frequency, with 25% of the species identified. At the end of the assay, treatment 20 had the highest positive influence and provided significant quantitative gains to the complex of traits related to cowpea production (SPD and hoeing at 18, 36, and 54 DAP). UPGMA cluster analysis and canonical discriminant analysis were performed and allowed a better classification of the evaluated treatments. It was observed that the first two canonical variables explained 90.8% of the total variance contained in the original variables. The use of SPD with weeding at 18, 36, and 54 days after planting provides greater weed control and significant quantitative gains for the complex of characteristics related to cowpea production. The results underscore the importance of choosing the correct cropping system and implementing effective weeding practices to optimize weed control and improve crop performance. [ABSTRACT FROM AUTHOR]

In guava plants, production pruning can be performed twice a year, and the return of growth is dependent on the physiological responses that are altered by the different cultivation environments and adopted management. From this perspective, this study aimed to characterize the photosynthetic dynamics of guava plants influenced by different pruning and fruit thinning intensities during two growing seasons in the region of Currais, Piauí, Brazil. The plants were distributed in a randomized block design with a factorial arrangement (3 × 3 × 2) consisting of three pruning intensities (short, medium, and long) and three fruit thinning intensities (0, 10, and 20%) during two growing seasons. The data were subjected to a cluster analysis and canonical discriminant analysis to discriminate treatment groups based on the variables. Through a cluster analysis for the evaluated treatments, it was possible to split the two pruning seasons into five different groups clustered for the first pruning season and the second pruning season. The highest assimilation values were observed in the first pruning season and especially in plants that received short pruning with 0% fruit thinning, medium pruning with 10% and 20% fruit thinning, and long pruning with 10% fruit thinning. Through the graphic representation of the canonical discriminant analysis, the first two variables explained 93.40% of the total variance contained in the nine original variables. The highest means of ambient PAR, transpiration, leaf temperature, internal carbon, and ambient temperature were observed in the second pruning season and in plants that received short pruning with 10% and 20% fruit thinning, medium pruning with 0% and 20% fruit thinning, and long pruning with 0%, 10%, and 20% fruit thinning favors a higher photosynthetic accumulation in guava plants. We observed a multiplicity of responses; however, short pruning with 10% thinning should be considered for both seasons. [ABSTRACT FROM AUTHOR]

The definition of nitrogen doses for baru species becomes necessary because each forest species responds differently to nitrogen fertilization. The aim of this study was to evaluate baru seedlings' response to nitrogen, phosphorus, and potassium (NPK) fertilization and liming. The experiment was conducted in a greenhouse in a randomized blocks design, arranged in a 5 × 2 factorial scheme, being the factors consisted of five doses of nitrogen in covering (0, 75, 150, 225, and 300 mg dm−3) and substrate with and without limestone and PK, with four replications. At 60 days after transplanting, the plant height, stem diameter, number of leaflets, leaf area, shoot dry mass, chlorophyll content, N content in the leaves, root length, root volume, root dry mass, height/stem diameter ratio, shoot dry mass/root dry mass ratio, and Dickson quality index were evaluated. The substrate with liming influences positively the root dry mass. Nitrogen and PK fertilization promote increase in the relative chlorophyll content and N concentration in the leaves. [ABSTRACT FROM PUBLISHER]

Copyright of Nucleus Animalium is the property of Fundacao Educacional de Ituverava 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 Nucleus Animalium is the property of Fundacao Educacional de Ituverava 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 Nucleus Animalium is the property of Fundacao Educacional de Ituverava 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 Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical 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 Nucleus (16786602) is the property of Fundacao Educacional de Ituverava 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.)