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.