The effect of benomyl on Gloeotinia temulenta under laboratory and field conditions

Abstract

Laboratory studies confirmed that benomyl can completely suppress apothecial formation of Gloeotinia temulenta, the causal organism of blind seed disease in grasses. Field studies in Lolium perenne seed crops showed that benomyl, applied at 2.80 and 5.60 kg/hectare, reduced the numbers of apothecia formed by 80 and 90 per cent respectively, while no reduction was apparent at 0.56 kg/hectare. Better results were obtained when the compound was applied in November, just before flowering, than when applied in September or October. At the application rates used, benomyl did not protect plants against seed infection. However, the degree of suppression of apothecial formation possible with benomyl suggests that, in areas where reinfestation of fields with infected seed after harvest is light, the compound should control blind seed disease by limiting formation of apothecia, which are the source of ascospore inoculum, to insignificant proportions.