Inoculation Technique, Storage Period and Spore Concentration of Alternaria solani on Tomato for Early Blight Development

摘要

Effect of inoculation technique, inoculum concentration and storage period were evaluated on the development of early blight disease on tomato in relation to host susceptibility under controlled environmental conditions. Four inoculation methods wereused (spray inoculation, root dip inoculation, droplet inoculation and soil inoculation) with 104/ml spore concentration for better disease development on two susceptible varieties (Co-3 and Arka Vikash), in which the droplet method gave maximum PDI (85.19 and 81.48%). The droplet method gave better discrimination of resistance level at a range of conidial densities followed by commonly used spray inoculation methods. When culture of Alternaria solani was grown for 30 days on sorghum grains it gave minimum incubation period and maximum number of lesions on both susceptible varieties of tomato as compared to other storage period. Spore concentration 10 x 103 was better for disease development on both susceptiblevarieties.Mycelium growth in A. solani was recorded maximum at 12 days after inoculation on both potato dextrose agar and potato dextrose broth media.