Influência do sistema de irrigação na incidência e nas perdas ocasionadas pelo mosaico dourado do feijoeiro

Abstract

One of the most severe diseases in common bean (Phaseolus vulgaris L.) is golden mosaic caused by Bean golden mosaic virus (BGMV, genus Begomovirus, family Geminiviridae). This study aimed to evaluate the influence of different irrigation systems on the incidence and losses caused by BGMV in common bean. The experiment consisted of the evaluation of three irrigation systems (drip, sprinkler and micro sprinkler), installed as 225m2 strips in the experimental area of the Federal University of Alagoas, Rio Largo, AL. Each strip contained 12 plots of 1m2 each, with 20 plants per plot. The experiment was conducted over two seasons: October 2006 to January 2007 and October 2007 to January 2008. The incidence of golden mosaic was evaluated by visual inspection of symptomatic plants, and the asymptomatic plants were tested for the presence of begomoviruses by PCR. For yield evaluations, the weight of mature grains from all plants was quantified, and the average weight per plant in each plot was calculated. The results indicate that drip and sprinkler irrigation resulted in the highest (62.31%) and lowest (16.74%) incidence, respectively, of golden mosaic. There was no correlation between the incidence of golden mosaic and yield. However, healthy plants yielded three times more grain than diseased plants. © the Brazilian Phytopathological Society.