Effect of plant density on mini-tuber production potential of potato varieties through micro-plants under net-house in North Eastern Himalayan region

Abstract: The present study was conducted to standardize the crop geometry under net-house with micro-plants of two popular potato varieties, Kufri Himsona and Kufri Girdhari planted at two spacing viz., 20 x 10 cm and 15 x 10 cm at Central Potato Research Station, Shillong during 2013 and 2014. The effect due to spacing and varieties was significant for all the plant growth and yield parameters except for plant survival among varieties. Plant survival was better in all treatments (> 80%). The plant growth was superior in terms of plant height, at wide spacing (20 x 10 cm) although canopy cover was more at narrow spacing (15 x 10 cm). Kufri Himsona exhibited better growth with more stem height, number of leaves/plant, stems per plant and better canopy cover at 30 DAP than Kufri Girdhari. Kufri Himsona yielded better in terms of numbers and weight of mini-tubers per plant as well as per unit area compared to the variety Kufri Girdhari. More number of tubers per plant was observed at closer spacing (15 x 10 cm) but better yield per plant was obtained at wider spacing (20 x 10 cm) due to increased competition for nutrients, space, sunlight etc. leading to an increase in number of tubers per plant but subsequent decrease in total tuber yield per plant at closer spacing. At closer spacing more small sized tubers were harvested (<3g to 20g) while at wider spacing more larger sized tubers were harvested (over 20g). Among varieties, Kufri Himsona yielded more large sized tubers as compared to Kufri Girdhari. Thus depending on the seed size requirement and availability of area under net house, either narrow or wide spacing can be followed for production of mini-tubers from potato micro-plants in North Eastern Himalayan region.