MANAGEMENT OF BLACK SCURF (RHIZOCTOMIA SOLANI) OF POTATO THROUGH SEED TREATMENT WITH BOTANICALS

Abstract

In search of eco-friendly, non- hazardous way of managing black scurf (Rhizoctonia solani) disease of potato, experiments were conducted with fresh leaf extracts of 20 botanicals in water @ 1:5 W/V (16.7%) and 5th year @ 1:3 W/V (25.0%) for 30 min dip treatment of naturally infected tubers and then planted in naturally R. solani infected field at Central Potato Research Station, Gwalior (Madhya Pradesh) from 2004-05 to 2008-09. Vinca rosea (Sadabahar), Withania somnifera (Ashwagandha) and Ocimum canum (Tulsi) were very effective in the management of black scurf when seed tubers were treated in their fresh leaf extracts (@1:5 W/V) for 30 min. In freshly harvested produce (daughter tubers) disease incidence of 50.5 to 54.3% and disease index of 0.59 to 0.71% were recorded as compared to 90.8% incidence and 1.66 index in diseased tuber control treatment during 2008-09 (@ 1:3 W/V). In diseased tubers, black scurf intensity reduction was 64.5% with W. somnifera, 58.4% with O. canum and 57.2% with V. rosea. There were no difference in efficacy of the above three botanicals among themselves. Botanicals viz., Azadirachta indica (neem), Eucalyptus globulus (Eucalyptus) and Allium sativum (onion) also gave good control of black scurf. However, increase in concentration of botanical extracts from 1:5 to 1:3 W/V increased the efficiency of W. somifera by 14% in case of disease incidence and 7% in disease index but 10% incidence only in O. canum. Plant emergence and yields were not affected due to the treatment with botanicals. Study revealed that these eco–friendly botanicals have the potential to control black scurf and their continuous use may help in better management of the disease.