COMMON BEAN CULTIVARS BEHAVIOR IN CONVERSION AREAS TO ORGANIC PRODUCTION SYSTEM IN THE BRAZILIAN SAVANNAH

Abstract

The objective of this study was to evaluate the performance of common bean (Phaseolus vulgaris) cultivars in a low fertility area cultivated for more than two years with Brachiaria brizantha pasture. These conditions are similar to those of farmers who choose to join the organic system without the necessity of passing through the conversion period. A randomized complete block design with four replications was used. The study was conducted as a local evaluation test with cultivars Aporé, BRS Marfim, BRS Vereda, Pérola, BRS Timbó, Xamego, Jalo Precoce, Diamante Negro, BRS Talismã, BRS Valente, and BRS Radiante as treatments. Two experiments were carried out during 2003, one in the dry season under irrigation, and the other in the rainy season, in organic farming system and following principles and technical norms of Mokiti Okada Certifier. Under irrigation, there were no yield differences between cultivars. In the rainy season, the cultivars BRS Radiante, Jalo Precoce, and BRS Valente showed significant higher yields as compared with the remaining cultivars.The angular leaf spot (Phaeoisariopsis griseola) was the most severe disease, and the most susceptible cultivar to this attack was Pérola, in the rainy season.

KEY-WORDS: Phaseolus vulgaris; yield; cultivar evaluation; organic farming.