Abstract In breeding programs, understanding the potential of parents should be a way to spend significantly less time and costs to obtain new cultivars. For this, the objective of this study was to estimate the general and specific combining ability of parents aiming common bean breeding for resistance to Fusarium wilt (FW) based on disease severity and reduction in plant growth. Eight common bean genotypes were crossed in a 3 x 5 partial diallel mating scheme to obtain F1 hybrids. The parents and their 15 F1 hybrids were evaluated for severity of Fusarium wilt, area under the disease progress curve, percentage of plant height reduction and plant shoot fresh weight reduction and grain yield. The resistance of common bean to FW is controlled by a few dominant genes. The reduction in plant growth is controlled by a different set of genes that can increase the selection efficiency of parents for common bean breeding.

Estudou-se a eficácia da aplicação de Trichoderma spp. no controle do mofo-branco do feijoeiro cultivado no outono-inverno na Zona da Mata de Minas Gerais. Não houve efeito do antagonista em reduzir a severidade da doença, o que pode ser explicado pelas baixas temperaturas e pela alta pressão de inóculo no campo. Conclui-se que aplicações de Trichoderma não são recomendadas para o controle do mofo-branco do feijoeiro no outono-inverno em regiões com temperatura média abaixo de 20 °C, considerando que essa condição climática favorece mais o desenvolvimento do patógeno do que o do antagonista.

We studied the effectiveness of application of Trichoderma spp. in controlling white mold on common beans at the fall-winter crop in the Zona da Mata region of the State of Minas Gerais, Brazil. There was no effect of the antagonist in reducing the disease severity, which could be explained by the low temperatures and the high inoculum pressure in the field. We concluded that Trichoderma applications are not recommended for control of white mold on common beans at the fall-winter season in regions with average temperature bellow 20 °C, since this condition favor more the pathogen than the antagonist.