Avaliação das dimensões da região danificada pelo complexo broca-podridões em seis cultivares de cana-de-açúcar

Abstract

Evaluation of the dimensions of the plant damage by the borer-rot complex on six sugarcane cultivara This research was conducted to determine the dimensions of damage by the sugarcane borer D-itr'a iavuL is (Fabr. 1794) and the associated stalk rots induced by funcji on six sugarcane cultivara. For this determination, staiks were opened longitudinally to evaluate the lengtii, volume of the dama ge region and volumetric damage index (volume of the iawaqcd region in relation to the total volume of the internode). The highest proportion of damage was due to fungai rota. For six cultivars, the average damage duo to fungi was 70% with respect to length and 95% for both volume and volumetric damage index. The dimensions of the daniagcd region varied depending on cultivara. In general the least amount of damago was obser ved in cultivar CB 47-355 for ali variables meaaurod.The greatest amount of damage was observed in cuitivars NA 56-79 and IAC 48-65. Recebido em 06/07/88 Complexo formado pela broca Diatraea sacchoralis (Fabricius, 1794) e pe los fungos Colletotrichua falcatum Went e Fusariwn monilifsrmo Sheldon. 2 Pesquisa realizada com o apoio financeiro da FINEP. Parte da tese apresentada, pelo primeiro autor, como um dos requisitos ao Concurso de Livre-Dodncia pela ESALQ/USP.