The Effect of Salicylic Acid on the Reduction of Rizoctonia solani Damage in the Tubers of Marfona Potato Cultivar

This study was carried out to evaluate the effects of salicylic acid in Marfona potato cultivar (Solanum tuberosum L.) for reducing the pathogenesis of Rizoctonia solani in potato tubers under greenhouse conditions. The pots sterilized soils had been infected by R. solani (21B1 strain) two weeks before transplanting the potato plantlets. The seedlings were treated with 0 (control), 0.1, 0.2, 0.5, 1, 2 and 4 mM of salicylic acid every week. The results showed that treatment with 0.2 mM salicylic acid resulted in 73% reduction in the infection symptoms on the potato tubers (sclerotia). Moreover, the intensity of infection symptoms were further reduced by an increase in the concentration of salicylic acid. The least infection was observed when 0.5 mM salicylic acid was applied. The results also showed that the number of potato tubers was increased by the application of 2 mM salicylic acid to plants that had been infected with fungi. Base of the results obtained, the application of 0.2 0.5 mM salicylic acid resulted in the reduction of tuber losses caused by Rizoctonia fungi.