Biological Control of Potato Bacterial Wilt Diseases

Abstract

Potato (Solanum tuberosum L.) is considered one of the four major and important food crops around the world. This study planned to control bacterial wilt disease of potato using some bio-agents which isolated and identified from potato plant soil. Twenty isolates were selected and identified as the following three isolates belonging to Streptomyces spp. (Streptomyces antibioticus (SA1), S. albus (SA2), and S. mutabilis (SM1); five isolates belong to pseudomonas species (Pseudomonas fluoresces (PsF1), P. aeruginosa (PsA1), P. putida (PsP1), P. alecaligones (PsA2) and P. pseudoalcaligones (PsP2)) and twelve isolates were belonging to Bacillus spp. (Bacillus subtilis (BS1-8), B. cereus(BC1), B. badius (BB1-2), B. pumilus (BP1). In vitro, these isolates were examined against the growth R. solanacearum bacterium, where some isolates (BS3, PsF1, BS8, BS6, SM1, BS5, and BS4) were the most effective compared with other isolates. Bacillus subtilis (BS8); Pseudomonas fluorescence (PsF1) and Streptomyces mutabilis (SM1) isolates were selected as bio-agents to control potato bacterial wilt disease under in vivo condition, where these isolates led to reduced disease severity and to increase potato yield compared with the control. The application of bio-agents as drench treatment was more effective than tuber treatment, and isolates of S. mutabilis (SM1) and B. subtilis (BS8) were more effective than Pseudomonas fluorescence (PsF1) isolate.