Differential inoculation techniques of Colletotrichum acutatum on different part of pepper.

Abstract

An experiment was conducted to test the differential infectivity of Colletotrichum acutatum byinoculating different plant parts of pepper (Capsicum annum) on six different varieties. The conidialconcentration 1x106 per ml from five days old culture was used for artificial inoculation. Inoculation of leavesshowed infection as hypersensitive reaction in most of the varieties. The lesion size on twigs varied from 2.0to 9.6 mm at cent percent infection site. Severity was much more pronounced on vertical inoculated twigswith complete rotting in comparison to horizontal inoculation. On fruits, lesions were more prominent andclear on pinpricked fruits than apical cut fruits. Petal infection started showing symptoms as yellowish brownfollowed by orange brown with dry rotting. PBC-932-6-6-1 was having maximum resistance against diseasein comparison to other varieties. The findings indicate that C. acutatum can infect all above plant parts onchallenge inoculation. However, the degree of infectivity depends on differential resistance response ofvarieties and methods of inoculation. Inoculation on vertical cut end of stem was best technique for creatingdie-back infection while surface inoculation was best initiating anthracnose infection which can be successfullyutilized for quick screening and to study relation between dieback and anthracn