Chemical control of angular leaf spot and anthracnose on beans.
The efficacy of different fungicides in controlling the bean diseases angular leaf spot and anthracnose (caused by Phaeoisariopsis griseola and Colletotrichum lindemuthianum, respectively) was evaluated during 1997-98 in Passo Fundo, Rio Grande do Sul, Brazil. The fungicides used were: 80 and 120 g azoxystrobin, 250 g benomyl, 250 g carbendazim, 1500 g chlorothalonil, 2000 g mancozeb, 700 g thiophanate methyl, thiophanate methyl + chlorothalonil (700 g + 750 g), 1000 g cuprous oxide, cuprous oxide + mancozeb (1000 g + 2000 g), 125 g propiconazol, 200 g tebuconazol, and 200 and 300 g triphenyltin hydroxide stannane [fentin hydroxide]. The fungicides were sprayed at 93, 109 and 123 days after emergence. A self-propelled boom sprayer was used to broadcast fungicides. The fungicide treatments had a significant effect on yield. In treated plots, yield varied from 290 (cuprous oxide) to 2057 kg/ha (300 g triphenyltin hydroxide). In the control plot, the yield was 186 kg/ha. Angular leaf spot control was higher than 70% in treatments involving azoxystrobin, chlorothalonil, thiophanate methyl + chlorothalonil, propiconazol, tebuconazol, triphenyltin hydroxide. Only triphenyltin hydroxide stannane 300 g and azoxystrobin 120 g showed antracnose control greater than 70%. The fungicides tested did not show phytotoxic effects.