KẾT QUẢ NGHIÊN CỨU MỘT SỐ BIỆN PHÁP KỸ THUẬT NÂNG CAO NĂNG SUẤT GIỐNG KHOAI MỠ TRẮNG TRỤI TẠI HỮU LŨNG, LẠNG SƠN

In Huu Lung district, Lang Son, the yam is common crops, which has high use value and cultivated with traditional cultural practices. Before 2006, many local yam varieties were cultivated in large scale of district and occupied about 100ha, but from 2009, the total cultivated area was quickly decreased. Reasons identified to be traditional cultivation is not suited with changing environment; local varieties were degenerated and mulching material (rang rang grass) is limited. In order to maintain and develop local yam varieties, the study on some cultural practices to increase the yield of local trang trui Yam variety was conducted in Minh Son commune, Huu Lung in 2011. The reseach results showed, the best yam planting time is 25 Feb. - 5 Mar.; Best planting density is 4 tuber cut/m2 ; The best fertilizer application per ha is 20 ton animal manure + chimical fertilizer 120N+110P2O5+ 110K2O. Yam cultivation with staking gave economical efficiency higher than non - staking from 14,595 million to 39,549 million VND per ha.