Infestação de mosca branca (Hemiptera: Aleyrodidae) biótipo B em cultivares de soja no polo Paragominas grãos, Pará

Abstract

The aim of this study was to evaluate the infestation of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B in 19 soybean cultivars in the Paragominas grain pole, 2017/18 crop year. The cultivars selected for planting are based on those normally planted in the Paragominas grain complex and research institutions. The sampling of the incidence of B. tabaci biotype B started on the 7th day after plant emergence (DAE), and the number of eggs, nymphs and adults was recorded weekly, that is, 10 small leaves of the plant evaluated in each plot, until the end of the crop cycle. The number of eggs and nymphs of B. tabaci type B was recorded in the laboratory with the aid of a stereoscopic microscope and adults made in loco. The values obtained were transformed into (x + 0.5)1/2, for normalization of these and submitted to analysis of variance (ANOVA) by the F test (Fisher). Tukey at 5% probability. The cultivar M 8644 IPRO showed the lowest infestation of eggs of B. tabaci and RK 6813RR was the most infested; for nymphs, the highest infestation was observed in cultivar RK 6813RR while in BRS 9383 IPRO there was less infestation; the highest number of whitefly adults was observed in the cultivar P 99R03, and M 8808 had the lowest average of adult insects and the period of highest incidence of whitefly was in the egg stage, in the first seven days after emergence (DAE); the period of 7 DAE was the most infested by adults and whitefly eggs; 35 and 42 DAE more infested by pest nymphs; meteorological factors mean temperature, rainfall and relative humidity do not showed influence on whitefly infestation, and relative humidity explained only 35.59% for incidence of eggs in soybean and the occurrence of adults explained 81% for the same parameter (eggs).