On-line version ISSN 0718-3429
ALFREDO RAUER DE, Luís and CARLOS MARINGONI, Antonio. Control of angular leaf spot on dry beans with fungicides and its effect on plant production. Idesia [online]. 2012, vol.30, n.2, pp. 93-100. ISSN 0718-3429. http://dx.doi.org/10.4067/S0718-34292012000200012.
The angular leaf spot of dry bean caused by the fungus Phaeoisairopsis griseola is a very important disease on dry bean crops in Brazil. In propitious weather conditions, susceptible cultivars have significant losses due to this disease. In these conditions, fungicide usage is an important step for angular leaf spot management. Since the effects of this method of control on plant physiology are not known, this study had the following objectives: a) Verify the action of fungicide in physiological changes in dry beans (photosynthesis rate and stomatal conductivity); b) evaluate the efficacy of some fungicides for the control of angular leaf spot; and c) examine the effects of these fungicides on other agronomic parameters; weight of 100 grains, number of grains per pod and number of pods per plant. The dry bean cultivar used in this study was Perola. Four trials were conducted, two in a net greenhouse and two trials under field conditions. A spray of piraclostrobin, tebuconazol and tebuconazol+ trifloxistrobin increased photosynthesis rates, although stomatal conductivity was not changed. In addition, sprays of tebuconazol, piraclostrobin, metiram+piraclostrobin and azoxistrobin provided better levels of disease control and also higher weight of 100 grains, with the exception of azoxystrobin for this parameter.
Keywords : Phaseolus vulgaris L; Phaeoisairopsis griseola; chemical control.