Response of Walnut Genotypes to Gnomonia leptostyla (Fr.) Ces. & de Note. in Greenhouse

Authors

Abstract

Anthracnose, caused by Gnomonia leptostyla, Anamorph: Marssonina juglandis (Lib.) Magn.), is the most serious disease of walnut. The present study was designed to determine relative resistance to the disease in eleven walnut genotypes using a factoriel experiment on the basis of completely randomized design. After grafting of walnut genotypes, grafted plants were inoculated by a 105 spore per ml suspension of the pathogen. The results showed that germination of spores was higher on the upper surface of the leaves. The first symptoms of infection appeared on Z60 and Hartley four days after inoculation. The acervuli were produced first on K72 genotype about 27 days after inoculation. Two months after inoculation, evaluation was done in each plants by determination of the number and the mean diameter of spots and leaf infection percent. The results showed that there were significant differences among the genotypes in number and size of spots. The highst leaf infection percent occurred on Z60, K72 and Hartley, and Vina and Ronde de montignac showed the least leaf infection percent

Keywords