Effect of Pumpkin (Cucurbita pepo) Sowing Density on Weed Dynamic and Water Yam (Dioscorea alata) Yield in Southeastern Nigeria

A field study was carried out in Uyo, Southeastern Nigeria in 2011 and 2012 to compare the potential of using pumpkin intercrop as a means of cost effective weed management in water yam (Dioscorea alata) farm. The experiment was laid out in a randomized complete block design. The treatments were included no weeding, weeded (3x), chemical weeding (Raft 500) + supplemented hoe weeding at 12 weeks after planting (WAP), Dynamic population densities of 10,000, 20,000, 30,000 and 40,000 supplemented with one hoe weeding at 4 WAP. The result of the study showed that weeded 3x treatment performed better in all the growth and yield parameters assessed but not significantly (P 0.05) above the growth and yield values obtained from 30,000 population density of pumpkin. The weeded (3x) resulted to tuber yield of 22.81 and 20.75 t.ha^-1 in 2011 and 2012 respectively, while, the 30,000 pumpkin population density had tuber yield of 19.81 and 19.35 t.ha^-1 in 2011 and 2012 respectively. The least tuber yields 3.22 and 2.18 t.ha^-1 was obtained from no weeding treatment. The weeded (3x) treatment had 9-86 and 8-90 percentage tuber yield above other treatments but 13 and 8% over 30,000 pumpkin population density alone. The study suggests that pumpkin intercrop at 30,000 stands per hectare could effectively reduce weed interference in water yam farm.