Losses caused to wheat by root diseases and rizophagus insects, under four soil sanitary conditions

Abstract

In an experiment conducted in 1982 at the Centro Nacional de Pesquisa de Trigo-Empresa Brasileira de Pesquisa Agropecuária (National Wheat Research Center of EMBRAPA), Passo Fundo, RS, Brazil, the action of root diseases, rhizophagus insects, and borers Listronotus bonariensis kuschel, 1955 (Col., Curcullonidae), in reducing emergence and in the death of wheat seedlings and tillers, was determined. Tow wheat cultivars, Nobre and CNT 9, under four soil sanitary conditions, were used. Fungicides provided significant increases as to seedling emergence up to 32 days, test weight, one thousand-grain weight, spikes per m², spikes per plant, grain yield, and reduced infection level of common root rot. Insecticide application resulted in significant increases in number of spikes per m², spikes per plant, and grain yield, as compared to the control. Low spike rate observed in the experiment may be attributed to soil borne fungi, rizophagus insects, and borers.