Efficacy of bacterial isolates against causal agent of late blight of potato, Phytophthora infestans

Potato (Solanum tuberosum) is main crop in subtropical and temperate regions as vegetable crop. It is affected by Phytophthora infestans causing a devasting disease late blight. The chemical pesticides used against this disease in this present scenario cause pollution (soil as well as water) and adversely affect beneficial soil micro-flora, grazing animals and human beings.

An experiment was designed at the Department of Botany, K.V. Subharti College of Science, Swami Vivekanand Subharti University, Meerut (UP), India during 2017–2018. Three bacterial bioagents, Pseudomonas isolate 1 and 2 and Bacillus species was isolated from infected phylloplane and used against late blight pathogen, P. infestans. The efficacy of antagonistic bio-agents tested against mycelial growth, zoospore and zoosporangial germination of P. infestans by dual culture method and detached leaf method.

The present study focused on use of bio-agents or antagonistic bacteria to control late blight pathogen showed concentration biased potential inhibitory activity against mycelial growth, zoospore and zoosporangial germination. It means higher the concentration of bacterial isolate, greater the inhibitory effect on various tested parameters. Among the three tested antagonistic bioagents, Bacillus showed maximum zone of inhibition to late blight pathogen. The proved that the Pseudomaonas and Bacillus as potential antagonistic agent for ecofriendly sustainable management of pathogenic mycoflora, P. infestans.