Tratamento de sementes de soja com insumos biológicos no tombamento de plântulas causado por Sclerotium rolfsii

Abstract

Soybean is a crop of great relevance in the Brazilian and the fungus Sclerotium rolfsii is responsible for collar rot and seedling damping off, causing large-scale damage. In order to reduce the inoculum employed as biological control and fungi of the genus Trichoderma are an example of controlling agents. The research aimed to evaluate the effects of biological in treating soybean seeds against damping off of seedlings caused by S. rolfsii. For the colonization of soil doses of 0, 2, 8 and 16 grams of inoculum of S. rolfsii were employed. Sowing occurred after colonization by the fungus soil. The experimental design was completely randomized, factorial 5 (seed treatment) x 4 (doses - pathogen) with four replications. The treatments were: T1 = untreated seeds; T2 = Trichoderma; T3 = inoculant; T4 = Trichoderma + inoculant; T5 = fungicide. It was evaluated the number of emerged plants, damping off, speed of emergence and weight green and dry of roots and shoots. The seed treatments showed no results to encourage the early growth of soybean seedlings and doses of the pathogen were determinants for the occurrence of seedling damping off. Therefore, treatment of seeds with biological was not efficient in the control of the pathogen S. rolfsii, in the seedlings damping off. Increasing doses of the pathogen interfered inhibiting the emergence and early growth of soybean seedlings and increasing doses the registration seedling damping off.