Leaf pigments in cauliflower cultivated with different water conditions and silicon applications

Environmental factors and crop management can influence the characteristics of plant morphology and physiology, altering photosynthetic efficiency and mass accumulation. The study aimed to analyze the contents of leaf pigments in cauliflower cultivated under different conditions of water availability and silicon (Si) applications. The experiment was carried out in a protected environment in the city of Maringá-PR. A randomized block design, in a 3x4 factorial scheme, with three replacement conditions [40, 70 and 100% of crop evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four repetitions. The cauliflower cultivation, cultivar Sharon, was carried out in dystroferric RED NITOSOL. Daily evapotranspiration was determined with a constant level water table lysimeter and water replacement was performed with drip irrigation. Si was applied in split doses in three applications (initial, intermediate and final phases). At flowering, leaf tissue from the upper third of the plant was collected, with pigment extraction performed with pure acetone and determination in a spectrophotometer. At harvest, the leaf area of ​​the plants was determined. Data were subjected to analysis of variance and regression analysis. Cauliflower crop under water-deficient reduces leaf area development and alters chloroplast pigments dynamics. Silicon use in the soil increases leaf development, chlorophyll a and b contents, and reduces carotenoids concentration. Under water stress conditions, silicon addition to the soil improves cauliflower performance

Índice spad em algodoeiro herbáceo em função da aplicação de sulfato de níquel/ Spad index in herbaceous cotton in function of the nickel sulfate application

O Níquel (Ni) é um elemento que possui relação direta com o metabolismo do nitrogênio nas plantas, conseguindo em algumas culturas aumentar a produtividade, porém em altas quantidades pode desencadear um efeito de toxidez nas plantas. O medidor portátil de clorofila- SPAD, é utilizado para avaliar o nível de N na planta, indicando valores proporcionais de clorofila na folha. Dessa forma, o presente trabalho teve por objetivo  avaliar a resposta do algodoeiro submetido a doses crescentes de sulfato de níquel (22% Ni) aplicado via solo, sobre o teor de clorofila em folhas de algodoeiro. O experimento foi desenvolvido em condições de casa de vegetação, sendo conduzido em vasos contendo areia lavada. O delineamento experimental adotado foi em blocos casualizados, contendo oito tratamentos, sendo sete doses de sulfato de níquel (18, 36, 72, 144, 288, 576 e 1152 mg por planta) e o controle (0 Ni), aplicados sobre o genótipo de algodoeiro herbáceo (FM 975 WS) com seis repetições, totalizando-se 48 plantas. As doses foram aplicadas via solo e parceladas aos 30, 40 e 50 dias após a emergência (DAE). A leitura do índice SPAD foi obtida imediatamente antes da aplicação das doses de sulfato de níquel, aos 30 DAE, e em intervalos de 15 dias após a aplicação (45, 60 e 85 DAE). Os resultados indicaram que o Ni não apresentou nenhum efeito no aumento do índice Spad de clorofila, porém as doses de sulfato de Ni mais concentradas ocasionaram possível fitotoxidez às plantas

COTTON FIBER QUALITY AFFECTED BY WATER AVAILABILITY AND SILICON APPLICATION

The technological quality of cotton fiber is a fundamental criterion for determining the commercial value of the product, being influenced by the conditions of cultivation. The study aimed to analyze irrigated and non-irrigated cultivation systems and the management of silicon fertilization on cotton fiber characteristics. The experiment was carried out in the field in Selvíria-MS. It was adopted a randomized block design, in a 2x6 factorial scheme, with two cultivation conditions (irrigated and rainfed) and six doses of Si (0, 50, 100, 150, 200 and 400 g ha-1), with four replications per treatment. Seeds of the genotype TMG 11 WS were used. Irrigation was carried out with sprinklers spaced at 6x6 m. The application of Si via leaf was carried out at 50 and 70 days after emergence. From the cotton fiber, the characteristics of length, micronaire, strength, uniformity, elongation, reflectance, yellowing, degree of leaves, impurity and impurity particles were analyzed. The data submitted to analysis of variance by the F test, the means compared by the Tukey test (p <0.05) for the cultivation condition, and regression analysis for the amount of Si. The cotton fiber in irrigated cultivation showed improvement in the characteristics resistance, reflectance and yellowing. The application of Si via leaf reduced the leaf grade in the cotton fibers

Eficiência da utilização de água e energia na produção de tomate em diferentes condições hídricas

The efficient use of water and energy is fundamental to a sustainable agricultural practice. Deficit irrigationscan contribute to saving water and energetic resources. This work aimed at analyzing the influence of waterreposition in the water and energy efficiency use for growing tomato cocktail type tomato. The experiment wasconducted in vegetation house, and the randomized design was adopted with five levels of water reposition(25, 50, 75, 100 and 125% of evapotranspiration in culture (ETc)) and six repetitions. The morphological contentswere evaluated (number of bunches, number of abortions, fresh mass of aerial part, stem diameter and height),SPAD index (Soil Plant Analysis Development), water demand, productivity, energy use and energy productivity.Data were analyzed through variance analysis, average comparison, regression analysis and correlation. Waterdeficit affects growth, development and productivity of cocktail type tomato. The morphological developmentand the production yield show high correlation with water availability. The water replacement of 75% of ETc hasshown better efficiency in water and electricity use in growing cocktail type tomato.A utilização eficiente da água e da energia é primordial para uma prática agrícola sustentável. Irrigações deficitárias podem contribuir para economia dos recursos hídricos e energéticos. O objetivo do trabalho foi analisar o efeito da reposição hídrica na eficiência da utilização da água e da energia no cultivo de tomate tipo coquetel. O experimento foi conduzido em casa de vegetação, sendo adotado delineamento casualizado com cinco níveis de reposição hídrica (25, 50, 75, 100 e 125% da evapotranspiração da cultura (ETc)) e seis repetições. Foram avaliados componentes morfológicos (número de cachos, número de abortos, massa fresca da parte aérea, diâmetro do caule e altura), índice SPAD (Soil Plant Analysis Development), demanda hídrica, produtividade, uso de energia e produtividade energética. Os dados foram analisados por análise de variância, comparação de médias, análise de regressão e correlação. O desenvolvimento morfológico e o rendimento produtivo apresentaram elevada correlação com a disponibilidade hídrica. O déficit hídrico afetou o crescimento, desenvolvimento e a produtividade do tomate. A lâmina de 75% da ETc demonstrou melhor eficiência da utilização da água e de energia