Management of black scurf (Rhizoctonia solani) of Potato through organic approaches

Black scurf (Rhizoctonia solani) disease of potato is becoming prominent in many potato growing districts of Gujarat state which reduce quality and market value of the produce, resulting in economic losses. The field experiment was conducted during rabi season of 2014-15 in naturally infested field with scurf pathogen at Potato Research Station, S.D. Agricultural University, Deesa (Gujarat) with the objective to find out suitable management strategies for black scurf through organic approaches (bio-agents and organic amendments). Among different bio-agents (Trichoderma viride, T. harzianum. Pseudomonas fluorescens and Bacillus subtilis) tested against black scurf, the tuber treatment with 2 per cent boric acid spray along with tuber treatment with T. viride @ 10 g/kg seed before sowing recorded the lowest disease incidence (15.33%) and index (0.38) with highest total tuber yield (324.68 q/ha) with maximum income 2,57,414/ha. When price computed with healthy and diseased tuber yield among treatments, the maximum income variation was (92,986/ha) recorded by the same treatment followed by the tuber treatment with 3% boric acid spray before sowing (68,440/ ha). In case of various organic amendments tested, soil application of mustard cake @ 10 q/ha registered minimum disease incidence (37.33%) and disease index (0.66) as compared to rest of the organic treatment with highest total tuber yield (327.20 q/ha) with maximum income 2,65,010/ha. When price computed with healthy and diseased tuber yield among treatments, the maximum income variation was (1,12,990/ha) recorded by the same treatment followed by the neem cake @ 10 q/ha (56,660/ha). These organic treatments can provide an effective and economical management of black scurf of potato for cultivaters.