Pochonia spp. como promotor de crescimento vegetal

Abstract

The State of Tocantins presents a cerrado area, possessing great potential for the development of the agricultural sector. It focuses its main activities on livestock and grain production. The main factors of low productivity of agricultural crops, such as soybeans, are diseases caused by pathogens that inhabit the soil, which can cause severe losses with significant losses in productivity. Biological treatment in seeds with beneficial microorganisms is very little known. The Pochonia fungus has been shown to have a potential as a biological control agent and is very promising as a growth promoter in plants. Seed inoculation with the Pochonia fungus not only protects plants against various diseases, but also can improve growth and can act as a promoter of plant growth. The objective of this work was to determine the capacity of Pochonia spp. to synthesize indole acetic acid (IAA), phosphate solubilization capacity and promote plant growth in crops such as soybean and cowpea. The ability to synthesize IAA and phosphate solubilization capacity, BD medium added with K2HPO4 solution and CaCl2 were determined. The results obtained in the evaluations of IAA and phosphate solubilization even though in small quantities presented increases in relation to the control, presented results ranging from 0.77 to 7.45 μg mL-1 in AIA and from 3.48 to 13.42 μg mL-1 in phosphorus solubilization, and the strains that obtained the best result in the experiments were UFT-P02 and UFT-P04. DMA, DMR, DMT and plant height were evaluated in the greenhouse evaluations at 45 and 56 days after emergence, among the strains which showed the best relative efficiency in relation to the control were strains UFT-P05 and UFT -P03 with an increase of 77 and 75% respectively. In the dose test developed in the field, an increase of 1,083.7 kg ha-1 was obtained in relation to the control, and the dose that obtained the greatest increment was the dose of 3 kg of inoculant / 50 kg of seed with total yield of 4,115.7 kg ha-1. It is concluded from these studies that Pochonia spp. showed a potential in providing phosphorus to the plant, synthesizing IAA with this, promoting greater plant growth, thus increasing significant increases in grain yield.