The efficient use of phosphorus (P) in agriculture has been the main focus of research on this macronutrient. Phosphites, which have been considered plant stimulants, can contribute to increase the efficiency of the use of P by corn. The objective was to evaluate the influence of phosphite via leaf on the growth and accumulation of corn phosphorus in the initial growth phase under doses of P. An experiment was installed in a completely randomized design, in a 5 x 2 factorial scheme with four replications. At 45 days after planting, the plant height and stem diameter, shoot dry matter, stem and roots, contents, accumulation and P and the efficiency of using P (EUP) were evaluated. Phosphorus fertilization of corn, cultivated in chromium Luvisol in the initial stage is essential to increase its growth and the production of dry mass and accumulation of P. The phosphite applied via leaf did not produce additional benefit in growth, biomass production or phosphate nutrition of corn , but increased EUP at the intermediate dose (200 mg dm-3) of this nutrient.

The Isabel grape (Vitis labrusca × Vitis vinifera L.) is the most produced grape in Brazil, however, it has a short postharvest period due to rapid degradation during storage. The use of coating has been an alternative to prolong the shelf-life of fruits. The objective of this work was to evaluate the postharvest quality of 'Isabel' grapes coated with tamarind (Tamarindus indica L.) seed starch. The experimental design was completely randomized with five treatments with edible coating based on tamarind seed starch, at concentrations of 0, 0.5, 1, 1.5 and 2% and five replications. The grapes were immersed in the solutions with different concentrations and stored in B.O.D. at 12 ± 2 ° C and 85 ± 5% relative humidity for 12 days. Weight loss, color, pH, soluble solids, total titratable acidity, relationship between soluble solids and acidity, anthocyanins, flavonoids and vitamin C were evaluated. The 2% coating of tamarind seed starch was the most efficient, providing shelf life in 12-day grapes when stored at 12 ± 2 ° C and 85 ± 5% RH, and maintaining the main quality aspects, with higher SS / TA ratio and vitamin C.

To evaluate the effect of fertilization with N and Si on gaseous exchanges, dry mass, concentrations, accumulations and compartmentalization of nitrogen fractions in eggplant. The experimental design was a randomized entirely design, in a 5 x 4 factorial arrangement with four replications and one plant per plot, totaling 80 experimental units. The experiment was conducted in a protected environment at Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande, Campus of Pombal, Paraiba, Brazil, between July and September 2016. The nitrogen doses applied was 25, 125, 250, 350 and 500 mg dm-3 and four silicon doses was 0, 75, 150 and 200 mg dm-3 both supplied by root. In pre-flowering stage were evaluated growth components; gas exchange, which are: photosynthesis, stomatal conductance, transpiration rate and intercellular CO2 concentration; levels and accumulation of fractions of nitrogen (NO3-, NH4+, and total), and the silicon concentration in the leaves. There was no significant interaction (p >0.05) between the factors nitrogen and silicon doses for any of the evaluated variables. Nitrogen and silicon doses influenced the variables evaluated only independently each other. The nitrogen doses promoted increases in the photosynthetic rate and associated variables, dry matter yield of stem leaves and roots and in the concentration and accumulations of nitric, ammoniacal and total nitrogen in leaf, stem e roots and decrease the concentration of silicon in leaves. The silicon doses increased the leaf area index, the nitrate levels and accumulation in the roots and the silicon content in the leaves. In conclusion, the nitrogen supply increased the photosynthetic rate, dry mass and nitrogen accumulation and decreased the concentrations of silicon in leaf. Silicon did not interfered with growth of eggplant, however increased leaf area index, decreased nitrate levels and accumulations in the roots at lower doses of this element.

Frações de nitrogênio no solo e na fitomassa foliar de berinjela e rúcula sob doses de nitrogênio associadas à extratos de Nim Nitrogen fractions in soil and phytomass of eggplant and arugula under nitrogen doses associated with neem extracts

Regiões áridas -Brasil. I. Zuffo, Alan Mario. II. Série. CDD 333.7369 Elaborado por Maurício Amormino Júnior -CRB6/2422 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. 2019 Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. www.atenaeditora.com.br APRESENTAÇÃO A obra "As Regiões Semiáridas e suas Especificidades" aborda uma série de livros de publicação da Atena Editora, em seu II volume, apresenta, em seus 23 capítulos, com conhecimentos tecnológicos das regiões semiáridas e suas especificidades. As Ciências estão globalizadas, englobam, atualmente, diversos campos em termos de pesquisas tecnológicas. O semiárido brasileiro tem característica peculiares, alimentares, culturais, edafoclimáticas, étnicos, entre outros. Tais, diversidades culminam no avanço tecnológico, nas áreas de Agronomia, Engenharia Florestal,

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RESUMO A extração de vermiculita e caulim geram resíduos com grande potencial poluente. Estes materiais, embora ainda pouco estudados, podem ser aproveitados na agricultura, principalmente na produção de mudas, contribuindo para mitigar parte dos impactos ambientais da mineração. Objetivou-se avaliar o potencial de resíduos minerais como componente de substrato para produção de mudas de mamoeiro. Dois experimentos foram conduzidos em ambiente protegido, com resíduo de caulim e outro com resíduo de vermiculita. O delineamento experimental utilizado foi o DIC, com tratamentos correspondentes a cinco proporções de resíduos com quatro repetições, totalizando 20 unidades experimentais. Os tratamentos foram estabelecidos em T1 contendo 0% de resíduo de mineração (RM) + 75% de solo (S) + 25% de esterco bovino (EB), em T2 contendo 10% de (RM) + 65% (S) + 25% (EB), em T3 contendo 20% de RM + 55% de solo + 25% (EB), em T4 contendo 30% RM + 45% (S) + 25% (EB) e T5 contendo 40% de (RM) + 35% (S) + 25% (EB). Observou-se que a proporção 30% de resíduo de vermiculita ou de caulim proporcionou maior crescimento e qualidade de mudas de mamoeiro. Os teores de Ca, pH e capacidade de retenção de água do substrato se correlacionam positivamente com o crescimento e qualidade das mudas de mamoeiro, enquanto os teores de sódio e a porosidade total se correlacionaram de forma negativa. Concluiu-se que mudas de mamoeiro podem ser produzidas com substrato contendo 30% de (RM) de caulim ou vermiculita + 45% de (S)+ 25% de (EB).

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