Água salobra, biofertilizantes e Trichoderma harzianum na cultura do feijão-caupi, no Maciço de Baturité, Ceará

Abstract

The use of poultry or cattle biofertilizers associated with the use of Trichoderma harzianum applied to the soil can mitigate saline stress and maximize cowpea productivity. In this sense, this research aimed to evaluate the use of brackish water on the agronomic performance of cowpea crops under different biofertilizers in gas exchange and productivity, in soil with and without application of Trichoderma harzianum. The experiment was carried out under field conditions, in the experimental area of Fazenda Piroás, Universidade da Integração da Lusofonia Afro-Brasileira (UNILAB), Redenção, Ceará. The experimental design was in randomized blocks (DBC), in a sub-subdivided plot scheme, with six replications, with the plots being two electrical conductivities of irrigation water (0.8 and 4 dS m-1 ), the subplots being two types of biofertilizers of animal origin (bovine and poultry) and sub-subplots, with and without Trichoderma harzianum, with 6 replications. The physiological variables analyzed were: photosynthetic rate, transpiration, stomatal conductance, internal CO2 concentration and chlorophyll index. The productivity variables analyzed were: number of pods, pod mass, mass of one hundred grains, number of grains per pod, pod length, productivity and water use efficiency. Irrigation with higher salinity water (4.0 dS m-1 ) negatively affected photosynthesis, transpiration, stomatal conductance and internal CO2 concentration of cowpea. Poultry biofertilizer partially mitigated the deleterious effects of salinity on the variables number and mass of pods, productivity and water use efficiency of cowpea crops. The use of Trichoderma harzianum associated with fertilization with poultry biofertilizer was more efficient for pod length under saline stress. The application of Trichoderma harzianum mitigated saline stress and increased the productivity and water use efficiency of cowpea.