INTEGRATED MANAGEMENT OF STEM NECROSIS DISEASE OF POTATO IN CENTRAL INDIA

Field experiments on the integrated management of potato stem necrosis disease (PSND) at Central Potato Research Station, Gwalior (Madhya Pradesh) from 1997 to 2002 showed that delaying the planting of the potato crop from 4 October to 3 November reduced both the disease incidence (from 96 to 8%) and the disease index (from 23 to 2%), with the crop planted on 13 November completely escaping the disease. In a separate experiment, the most effective treatments for the control of PSND in potatoes planted in the second week of October were two foliar sprays of 0.07% imidacloprid at 21 and 35 days after planting (DAP), or a 10 min seed tuber dip in 0.07% imidacloprid plus one spray of 0.07% imidacloprid at 21 DAP. The PSND incidence and index were reduced from 41 to 9-12% and 10 to 2-3%, respectively. Slightly less effective in controlling PSND were seed treatments with 0.07% imidacloprid plus one foliar spray of 0.04% monocrotophos at 21 DAP, or one spray of 0.07% imidacloprid at 21 DAP alone or two sprays of monocrotophos at 21 and 35 DAP. The anti-transpirants, kaolin and indigo blue had little effect on PSND. Although polyethylene sheet or paddy straw mulching significantly reduced the incidence of PSND (from 49 to 35-41%) in potatoes planted in the first week of October, disease levels were too high to offer any practical benefits, if used alone.