Amita Pachori, Om Prakash Sharma, Shashi Singh Yadav and D.S. Bhadouria
Abstract
Alternaria solani is an aggressive pathogen that causes early blight of tomato. In the present study showed, variations in different isolates of Alternaria solani in morphological (conidial) characteristics, size of beak, size of conidia and mean number of septa. Isolate MRN-2 produced maximum conidial length (285.0 μm), number of horizontal septa (8-10). The first symptom of early blight of tomato occurs on leaf (leaf spots resemble concentricrings-a distinguishing characteristic of the pathogen) as an isolated patch more or less circular in outline which enlarges as the season advances. Out of 20 tomato cultivars screened, one cultivar was found resistant, four have been found moderately resistant and eight cultivars were found susceptible and remaining seven cultivars were found highly susceptible.