Comportamento de variedades paulistas de algodoeiro em solo infestado pelo fungo causador da murcha verticilar Translated title: Comparative reactions of some cotton varieties to Verticillium wilt in field conditions

Abstract

Foi estudado o comportamento de variedades paulistas de algodoeiro em terreno infestado pelo fungo causador da "murcha de Verticillium", no Estado de São Paulo. As variedades IAC RM3 e IAC RM4, resistentes à Fusariose, destacaram-se em produção e apresentaram as menores porcentagens de plantas com sintomas externos da doença estudada. Os resultados sugerem que tais variedades constituem também fontes genéticas de resistência à murcha verticilar.

Translated abstract

A study was made on the reactions of the cotton varieties commonly cultivated in the State of São Paulo (Brazil) to Verticillium wilt under field conditions. The effects of the disease were evaluated by determining the percentages of plants showing the symptoms of the Verticilliumwilt and by measuring the yield of each variety. The Fusarium resistant varieties IAC RM3 and IAC RM4 gave the highest yields and the lowest percentages of plants infected by Verticilliumwilt. It is suggested that these varieties might represent sources of resistance to Verticillium wilt.