Eleven fungicides were sprayed on field crops of two beans (Phaseolus vulgaris L), cvs. Carioca and Carioca 80, to evaluate their effect on yield performance and disease control under natural conditions of infection. The trials were carried out during four periods: fall of 1985 and 1986 and spring of 1985 and 1986. The tested fungicides were: benomyl, mancozeb, methil thiophanate, captafol, chlorothalonil, triphenyltin acetate, carbendazim, thiabendazole, copper oxychloride, copper sulfate and triphenyltin hidroxide. During the fall of 1985 the fungicides captafol, chlorothalonil, triphenyltin acetate and carbendazim resulted in high yield for the cv. Carioca; while for the cv. Carioca 80, mancozeb, chlorothalonil, triphenyltin acetate, copper oxychloride and copper sulfate were more efficient. During the spring of 1985 and fall of 1986, the fungicides did not give a significant increase on yield. During the spring of 1986, the best fungicides for the 'Carioca' were triphenyltin acetate and triphenyltin hidroxide, and for the 'Carioca 80', the triphenyltin hidroxide was the best fungicide. The rust was not a very important disease. It occurred only in two periods: fall and spring of 1986 and the higher medium note was 2 (as 25% of the foliar area was affected). The best fungicide for the control of this disease was chlorothalonil. The leaf spot caused by Phaeoisarlopsis griseola was the most frequent and severe disease. The leaf spot caused by Alternaria occurred in all periods. The leaf spot caused by Xanthomonas campestris pv. phaseoli also occurred on a generalized form, but, it did not affect the pods of the tested cultivars. These three diseases were better controled by mancozeb, chlorothalonil, triphenyltin acetate and triphenyltin hidroxide.
beans; Phaseolus vulgaris L; yield; diseases; chemical control