CONTROLE COM VÍRUS CONTRA Chrysodeixis includens, SOB TAMANHO FORA DA RECOMENDAÇÃO, EM PLANTAS DE SOJA

Abstract

Most Chrysodeixis includens caterpillars, a severe defoliating pest on soybean plants, should be sampled at smaller sizes (1 to 6 mm in body length) for greater efficiency of virus-based microbiological products. However, the farmer who does not use caterpillar sampling has difficulty in seeing the appropriate NPV application-time, which may justify certain cases of low efficiency in the field. As the development of the immature phases of noctuids is very fast, the search for microbiological products, as well as combinations of dosages and external catalysts that can increase the virulence of these biological control micro-agents should be investigated. The objective was to evaluate the number of C. includens caterpillars, of medium size (7 to 16 mm), in soybean plants after foliar spraying of water (T1, absolute control), Indoxacarb (Oxadiazine insecticide) (T2), Bacillus thuringiensis var. kurstaki (T3), Surtivo®Soja100: HearNPV + ChinNPV (T4), Surtivo®Soja100 + molasses (T5), Surtivo®Plus140: AcMNPV + HearNPV + ChinNPV + SfMNPV (T6) and Surtivo®Plus140 + molasses. The test was conducted in a commercial crop of Glycine max L. (cv. Syngenta 1163 RR®). The number of median caterpillars (7 to 16 mm) was counted, by tapping cloth, at 0, 4, 8, 14 and 21 days after application. The target of applications with Surtivo®Soja100 and Surtivo®Plus140 are small caterpillars, but these treatments also reduced the number of medium-sized caterpillars, which increases the prospects for using these products in soybean IPM field-based programs.