Bioestimulant efect of Trichoderma atroviride in anco pumpkin (Cucurbita moschata Duch. ex Poir)

Abstract

The biostimulant effect of Trichoderma atroviride on seedling growth and commercial yield of pumpkin (Cucurbita moschata) has been assessed. The seedling stage was evaluated in a greenhouse and the treatments were T0: control -without inoculation-; T1: 200 ml.m^-2 and T2: 500 ml.m^-2 of T. atroviride SC 10⁸ conidia. After 30 days, number of plants; root length; seedling height; number of sheets; aerial and root fresh and dry weight and root/aerial index were evaluated. Significant differences were found for seedling height in T1 compared to T0 and T2. The average air fresh weight was significantly higher in T1 compared to T2. The root fresh weight was statistically higher in T2 compared to the rest. Seedlings treated with higher doses of T. atroviride registered an increase in root mass, and below ground biomass indexes were closer to 1. The other variables did not register any statistical difference between treatments and T0. In the field, the treatments were as follows: T0: without inoculation; T2 and T3 inoculated with 20 ml.m^-2 and 50 ml.m^-2 in seedling stage respectively, and addition of 3 l.ha^-1 of T. atroviride SC 10⁸ conidia to the transplant. At 100, 108 and 115 days after the transplant (DPT), it was harvested. The number of plants that remained until the harvest and the fruits’ ammount and weight per plant were considered. T2 differed significantly, surpassing T0 and T1 in number of plants at harvest time. The amount of fruits did not show significant differences along the harvests. However, T2 showed greater weight of commercial fruits harvested at 108 DPT, providing greater precocity.