Salinity in soil can affect Jatropha seedling metabolism, interfering with plant establishment. In this study, the effect of salinity on the mobilization of reserves during the development of Jatropha seedlings was tested. Two genotypes of Jatropha were used and three concentrations of NaCl were applied between the 4th and 8th days after germination. The effects of salinity on seedling growth, in terms of fresh and dry phytomass, ionic partition, and sugar quantification, starch, proteins, amino acids, and lipids were evaluated in cotyledon leaves, hypocotyls, and roots. There was an increase in the content of all classes of macromolecules analyzed in at least one of the organs. It is hypothesized that the hypocotyls acted as an accumulating organ of Na⁺. The accumulations of amino acids and protein in roots suggest that metabolic responses occurred in response to the ionic and osmotic effects of NaCl, although this accumulation did not appear to prevent biomass losses in seedlings. Furthermore, the findings of this study demonstrate that salinity inhibits the mobilization of lipids and carbon stocks from cotyledon leaves to the rest of the plant, and together with the synthesis of proteins and amino acids that occurred primarily in roots, contributed to response of these plants to salinity.

Brassinosteroid is a hormone that in addition to favoring the growth and development of the plant is pointed out as attenuator of the negative effects caused by water stress in vegetables. The papaya has socioeconomic importance and the water deficit is a limiting factor to its growth, therefore, it was aimed to evaluate the effects caused by the application of epibrassinolide (C28H48O6), a brassinosteroid analogue, during the vegetative phase of the papaya under different irrigation slides. The experiment was conducted in the experimental field belonging to the State University of Paraíba, Catolé do Rocha -PB campus, using the Hawaí variety. In factorial scheme 5x2, with four blocks and five irrigation slides (60, 80, 100, 120, 140% of reference evapotranspiration-ET0), with brassinosteroid (concentration 1.0 mg L-1) and without brassinosteroid. The hormone was applied via the leaves at 60 days after transplanting for two consecutive days, this procedure being carried out inside a closed chamber and using a manual sprayer, 35 days after the complete exposure of the plants to the treatments, parameters were evaluated. at which it was found that there was a significant interactive effect between the factors studied (blades x hormone) in most of the variables evaluated. Smaller irrigation depths promoted lower height, diameter, number of leaves, leaf area and root volume of papaya seedlings. The use of 100% of the reference evapotranspiration provided greater height, stem and root moisture. The application of 1.0 mg L-1 of the hormone optimized plant growth in the seedling production phase, however, it did not alleviate the harmful effects of the water deficit. KEYWORDS: Carica papaya L., water deficit, phytohormone RESUMO: O brassinosteróide é um hormônio que além de favorecer o crescimento e desenvolvimento da planta é apontado como atenuante de efeitos negativos provocados pelo estresse hídrico em vegetais. O mamoeiro apresenta importância socioeconômica e o déficit hídrico é um fator limitante ao seu crescimento, logo, objetivou-se avaliar os efeitos causados pela aplicação do epibrassinolide (C28H48O6), um análogo do brassinosteróide, durante a fase vegetativa do mamoeiro sob diferentes lâminas de irrigação. O experimento foi conduzido em campo no setor experimental pertencente à Universidade Estadual da Paraíba, campus Catolé do Rocha –PB, utilizando-se a variedade Hawaí. Empregou-se esquema fatorial 5x2, com quatro blocos, sendo cinco lâminas de irrigação (60, 80, 100, 120, 140% da evapotranspiração de referência-ET0), com brassinosteróide (concentração 1,0 mg L-1) e sem brassinosteróide. A aplicação do hormônio foi efetuada via foliar aos 60 dias após o transplante por dois dias consecutivos, realizando-se esse procedimento dentro de uma câmara fechada e por meio de um pulverizador manual, 35 dias após a completa exposição das plantas aos tratamentos foram avaliados parâmetros de crescimento aos quais constatou-se que houve efeito significativo interativo entre os fatores estudados (lâminas x hormônio) na maioria das variáveis avaliadas. Menores lâminas de irrigação promoveram menor altura, diâmetro, número de folhas, área foliar e volume radicular das mudas de mamoeiro. O uso de 100% da evapotranspiração de referência proporcionou maior altura, umidade caulinar e radicular. A aplicação de 1,0 mg L-1 do hormônio otimizou o crescimento das plantas na fase de produção de mudas, porém, não amenizou efeitos deletérios do déficit hídrico. PALAVRAS-CHAVE: Carica papaya L., déficit hídrico, fitohormônio. Brassinosteroid is a hormone that in addition to favoring the growth and development of the plant is pointed out as attenuator of the negative effects caused by water stress in vegetables. The papaya has socioeconomic importance and the water deficit is a limiting factor to its growth, therefore, it was aimed to evaluate the effects caused by the application of epibrassinolide (C28H48O6), a brassinosteroid analogue, during the vegetative phase of the papaya under different irrigation slides. The experiment was conducted in the experimental field belonging to the State University of Paraíba, Catolé do Rocha -PB campus, using the Hawaí variety. In factorial scheme 5x2, with four blocks and five irrigation slides (60, 80, 100, 120, 140% of reference evapotranspiration-ET0), with brassinosteroid (concentration 1.0 mg L-1) and without brassinosteroid. The hormone was applied via the leaves at 60 days after transplanting for two consecutive days, this procedure being carried out inside a closed chamber and using a manual sprayer, 35 days after the complete exposure of the plants to the treatments, parameters were evaluated. at which it was found that there was a significant interactive effect between the factors studied (blades x hormone) in most of the variables evaluated. Smaller irrigation depths promoted lower height, diameter, number of leaves, leaf area and root volume of papaya seedlings. The use of 100% of the reference evapotranspiration provided greater height, stem and root moisture. The application of 1.0 mg L-1 of the hormone optimized plant growth in the seedling production phase, however, it did not alleviate the harmful effects of the water deficit. KEYWORDS: Carica papaya L., water deficit, phytohormone.

A cebola apresenta alta sensibilidade ao déficit hídrico, principalmente na fase de bulbificação. Em sistemas orgânicos, essa característica é intensificada, tornando o manejo da irrigação decisivo para o crescimento e a produtividade. Este estudo teve como objetivo avaliar o impacto de diferentes lâminas de irrigação no crescimento e na produtividade comercial da cebola em sistema orgânico, ao longo de dois experimentos de campo conduzidos em 2014 e 2015. O delineamento experimental foi em blocos casualizados, com cinco repetições e quatro lâminas de irrigação (42%, 50%, 83% e 100% da lâmina total, controladas por Acionador Automático para Irrigação - AAI). Foram avaliadas a biomassa seca de planta (BSP), o índice de área foliar (IAF), a área foliar (AF), as taxas de crescimento da cultura (TCC) e de assimilação líquida (TAL), e a produtividade comercial de bulbos. Em 2015, as maiores lâminas de irrigação (83% e 100% do AAI) promoveram significativamente maior acúmulo de biomassa, área foliar e taxa de crescimento. Embora em 2014 não tenham sido observados efeitos significativos das lâminas sobre os parâmetros de crescimento vegetativo, em ambos os anos, a produtividade comercial de bulbos foi superior com o uso das maiores lâminas de irrigação. As lâminas reduzidas (42% e 50% do AAI) resultaram em menor crescimento da cultura e reduções expressivas na produtividade. Conclui-se que a aplicação de lâminas de irrigação adequadas é fundamental para otimizar o crescimento e a produtividade da cebola em sistemas orgânicos, sendo o déficit hídrico um fator limitante severo.

The objective of this work was to evaluate the effect of planting densities of apple type banana "BRS Princesa" on the development and productivity of the crop in two production cycles. The research was carried out in the agricultural years of 2014 to 2016 in the Department of Horticulture of the Federal Rural University of Rio de Janeiro (UFRRJ), municipality of Seropédica, Rio de Janeiro, Brazil. The treatments were composed of planting densities, being 1200 (3.33 x 2.5 m); 1600 (2.5 x 2.5 m); 2000 (2.0 x 2.5 m); 2400 (1.67 x 2.5 m); 2800 (1.43 x 2.5 m) and 3200 (1.25 x 2.5 m) plants per hectare, arranged in a randomized complete block design with four replicates. In the vegetative stage, plant height and base diameter were measured periodically. In the production period, bunch weight, fruit weight, number of leaves, number of fruits, weight of the stalk, leaves active at harvest and yield of the crop were measured. The data were submitted to analysis of variance through the F test, adjusted to regression models. There were no significant differences in plant height, but for the base diameter variable, higher values were observed in the lower population density in the two production cycles. In the production stage, it is highlighted that the plant densification extended the life cycle and the production cycle of banana plants. Although the densification promoted a lower bunch weight, a lower quantity and weight of fruits, fortuitously, promoted higher productivity, with values above 20 t.ha-1 in both cycles.

The pineapple crop (Ananas comosus) is of socio-economic importance in Maranhão, with the regional cultivar 'Turiaçu' standing out for its sensory qualities. However, local productivity is lower than the national average and the lack of studies on sustainable management limits its potential. The aim of this study was to evaluate the development, productivity and fruit quality of the 'Turiaçu' pineapple under application of aerobic biofertilizer (BA), compared to mineral fertilizer, and to analyze the effect of different soil covers (plastic mulch and burlap). The experiment was conducted in a randomized block design (RBL), with 8 treatments and 4 replications, totalling 576 plants. The treatments included combinations of BA (applied every 14 days), plastic mulch, leaf litter, synthetic fertilizer (control) and an untreated control. Vegetative (fresh and dry mass, length and width of leaf D), productive (fruit mass and size, basal and apical diameter, natural flowering, toppling) and quality (soluble solids, incidence of fusarium and fruit grading) characteristics were evaluated. Mulch as a soil cover promoted greater growth of the 'Turiaçu' cultivar. In contrast, chemical fertilization proved ineffective and plastic mulching caused plant instability. Although the use of BA did not outperform burlap in terms of productivity, it showed potential when associated with organic practices. It can be concluded that litter is a promising alternative for managing the 'Turiaçu' pineapple, favoring the development and sustainability of production.

A crescente demanda por alimentos em regiões áridas e semiáridas, aliada às mudanças climáticas, reforça a necessidade de tecnologias eficientes para a gestão de recursos hídricos. As barragens subterrâneas (BS) surgem como alternativa eficaz para armazenar água no subsolo, fornecendo suprimento para consumo humano, animais e atividades agrícolas, contribuindo para a segurança hídrica. Este estudo teve como objetivo identificar os critérios e metodologias utilizados na seleção de locais adequados para implantação de BS. Realizou-se uma revisão sistemática em periódicos científicos, consultando bases como SciELO, ScienceDirect, Portal de Periódicos da CAPES e Google Acadêmico, abrangendo 2013 a 2024, com a seleção de 12 artigos relevantes. Os resultados indicam que a ineficiência das BS está frequentemente associada à escolha inadequada do local. Ferramentas como SIG, GIS e métodos multicritério (AHP, EDAS e TOPSIS), combinadas com critérios geológicos, hidrológicos, de declividade e socioeconômicos, têm sido aplicadas para otimizar essa seleção. Observou-se que, embora países como Irã e Turquia apresentem bons resultados, ainda há escassez de estudos aprofundados no Brasil. O trabalho evidencia a necessidade de pesquisas adicionais e do uso de tecnologias para identificar áreas ideais, promovendo a sustentabilidade e segurança hídrica regional.