Influence of dates of planting and haulms killing on the yield of seed sized tubers in Shimla hills*

Field experiment with four dates of planting and three dates of haulms killing was conducted during 1996 and 1997 at Central Potato Research Station, Kufri to find out the optimum dates of haulms killing and planting for maximising the number of seed sized tubers (20–80g). The crop planted on 1 May with 105 days of haulms killing produced maximum number of seed sized tubers (4.83 lakhs/ha) as well as highest seed yield of 239 q/ha. This treatment was followed by planting on 15 April with 105 days haulms killing. The crop planted on 1 and 20 June on an average, produced less number of seed sized tubers than the crop planted on earlier dates but planting on these dates with 75 days haulms killing produced higher number of seed sized tubers. The ratio of seed rate to seed yield was also highest with crop planted on 1 May with 105 days haulms killing. The percentage increase in number of total and seed sized tubers was highest in crop planted on 1 June while the increase in their yields was highest in crop planted on 20 June with 75 days haulms killing. About 80% of potato produce was in seed sized fraction.