EFFECT OF GROWTH PROMOTOR AND BIOPROTECTOR ON THE DEVELOPMENT OF IRRIGATED RICE AND BROWN SPOT INCIDENCE

Abstract

Two experiments were carried out to evaluate the effect of two commercial products, one containing plant-growth promoting rhizobacteria (PGPR) and micorrhizae, and the other containing micronutrients and aminoacids, on the development of irrigated rice. One kilogram of the biological product Biosol (trade mark) was added to the seeds at sowing time (1kg / ha) and the biofertilizer Greensol (trade mark) was sprayed by airplane (200 ml / ha) in association with fungicides, when 5% of panicles had been emitted. The treatments used were T1: Control; T2: Greensol; T3: Biosol + Greensol and T4: Biosol. Five parameters were evaluated: number of shoots per meter, dry weight 90 days after sowing, grain yield, empty grains percentage and incidence of brown spot disease (Helminthosporium oryzae Breda de Haan). Number of shoots per meter was uniform in all treatments. Grouped analysis indicated superiority of all treatments with Biosol over the control for the parameters of dry weight of plants and roots. Treatments T3 and T4 presented superior yields. In these treatments empty grain percentage was lower than the control. Brown spot severity index indicated that all treatments were better than control and T3 and T4 treatments had the lowest disease index.

KEY-WORDS: Helminthosporium oryzae; Oryza sativa; disease control; rice.