Khalil I. Al-Mughrabi1
Partner: Potatoes New Brunswick
Abstract: Trials were conducted at the Potato Development Centre, Wicklow, New Brunswick, Canada to study the effect of salicylic acid (SA) in suppressing black scurf (Rhizoctonia solani Kuhn, AG-3) disease in potatoes (cv. Atlantic) under screenhouse conditions. The trials were designed as a completely randomized block and comprised of eight replicated treatments: Untreated, uninoculated control (CTH); untreated control inoculated with R. solani (CTD); healthy seed treated with SA (STH); seeds inoculated with R. solani and treated with SA (STD); healthy seeds with SA applied foliarly (FAH); seeds inoculated with R. solani and SA applied foliarly (FAD); healthy seeds with SA applied as soil drench (SDH); seeds inoculated with R. solani and SA applied as soil drench (SDD). Seedling emergence, plant canopy, disease severity of black scurf and total tuber weights were recorded. Plant canopy was significantly higher in plants inoculated with R. solani and treated with SA compared to uninoculated treatments. All SA treatments significantly reduced black scurf disease severity in stems compared to the untreated, inoculated controls. Compared to the CTD, black scurf disease severity in stems was reduced by 89.6% and 88.8% when FAH and SDH treatments, respectively, were used. Treatments inoculated with R. solani and treated with SA significantly increased potato tuber weights compared to the uninoculated controls. This is the first study of its kind to investigate the capability of SA in inducing resistance in potatoes against the black scurf pathogen and its effect on tuber yield.
1Potato Development Centre, New Brunswick Department of Agriculture and Aquaculture, 39 Barker Lane, Wicklow, New Brunswick, Canada E7L 3S4