Everaldo Moreira da Silva

Tolerância ao déficit hídrico em genótipos de feijão-caupi

ABSTRACT The objective of this study was to evaluate physiological and productive characteristics of cowpea underwater deficit and total irrigation, under soil and climate conditions of Teresina, Piaui State, in 2008. Thestomatal conductance, leaf water potential, leaf temperature and grain yield of twenty cowpea cultivarswere evaluated. Two experiments were carried out in a randomized block design with 20 treatments andfour replications, one under water deficit during the reproductive phase and another one under totalirrigation. The water deficit was obtained applying half of the water depth required by cowpea. The waterdeficit reduced 72% of the stomatal conductance, 40% the leaf transpiration, 62% of the leaf waterpotential, 60% of the grain yield and increased 11.7% the leaf temperature. Under water deficit, 13genotypes produced above average (466 kg ha -1 ), and BRS-Paraguacu, Pingo-de-ouro-1-2 andPingo-de-ouro-2 presented the best grain yield with712 kg ha -1 , 667 kg ha -1 and 642 kg ha

Identification of cowpea genotypes for drought tolerance

The genotypes selection for drought tolerance is very important for world food production, principally in arid regions or sites with irregular rain distribution. The objective of this work was to identify cowpea genotypes with drought tolerance and water stress sensitivity characteristics. Two experiments were carried out with 20 treatments and four replications, one under water deficit during reproductive phase and another one under full irrigation. The water deficit was obtained applying half the water depth required by cowpea. The leaf area index, chlorophyll content, grain components and grain yield were evaluated. The water deficit reduced 20% the leaf area index, 16% the chlorophyll content, 175% the pod number per plant and 60% the grain yield. The genotypes Santo Inacio and Tracuateua-192 present sensitivity to water deficit in soil andBRS-Paraguacu, Pingo-de-ouro-1-2 and Pingo-de-ouro-2 show behavior for drought tolerance.

Níveis de salinidade e manejo da fertirrigação sobre características da berinjela cultivada em ambiente protegido

Objetivou-se estudar os efeitos de diferentes niveis de salinidade do solo sobre as variaveis fenologicas e de producao da berinjela, cultivada em vasos e em ambiente protegido. O estudo foi conduzido na area experimental do Departamento de Engenharia de Biossistemas da ESALQ/USP, Piracicaba, SP. Os tratamentos foram compostos da combinacao de dois fatores: 6 niveis de salinidade inicial do solo (S1 = 1,3; S2 = 2,4; S3 = 3,6; S4 = 4,5; S5 = 5,6 e S6 = 6,4 dS m-1) e dois manejos de fertirrigacao: com controle da condutividade eletrica da solucao do solo (M1), e o tradicional (M2), obedecendo a curva de absorcao de nutrientes da cultura. O delineamento estatistico adotado foi o de blocos casualizados completos, com quatro repeticoes, arranjados no esquema fatorial 6 x 2. Os resultados revelaram que os niveis de salinidade do solo afetaram diretamente as variaveis, producao de materia seca, producao de frutos e indice de area foliar das plantas. Verificou-se que a reducao media na producao da cultura da berinjela, em estufa, foi da ordem de 8,65% para o incremento de 1 dS m-1 na salinidade do solo, acima da salinidade limiar, que foi de 1,71 dS m-1.

Aspectos de sorção para os materiais inconsolidados da região de São Carlos (SP), Brasil

The transport of liquid and gaseous pollutants through porous geological media depends on the physical and chemical characteristics of the unconsolidated material, rocks and water, associated with the characteristics of the pollutants. Of these characteristics, the sorption aspect is of fundamental importance and is a function of the mineral proportions, pH, Eh and void aspects encountered in the porous media. In the Sao Carlos region, located in the eastern-central part of the State of Sao Paulo, Brazil, there are basically two types of unconsolidated materials: the first is a residual from sandstones cemented with fines and the secondarily composed of claystones, siltstones and conglomerates from the Cretaceous Period that constitute the Itaqueri Formation; the second is a sandy sediment of the Tertiary Period. These geological conditions are found in areas where chemical products are disposed of, characterized as either diffuse or point pollutions sources. Because of this situation, a study was developed to evaluate the sorption aspects of some inorganic cations that are frequently found in these sources, in varied concentrations. Taken into consideration were their physical/chemical properties, such as: specific weight, grain size, mineralogy, cationic exchange capacity, pH, hydraulic conductivity. Batch tests were run using solutions of KCl, ZnCl2 and CuCl.H2O at three different pH values, and then with a combined solution (KCl + ZnCl2 + CuCl.H2O), also at three different pH values.