Abstract

The potential of Fulan (2,5-dimethoxytetrahydrofuran), a synthetic nematicide applied at 10 g /stand and two plant bed types; ridging and mounding to manage plant parasitic nematodes and increase the yield of yam was investigated at Ejura during 2011 and 2012 at three levels of N-P₂0₅-K₅0 (NPK). The factorial experiment was mounted on randomized complete block design and replicated three times. Ridged bed type + the highest level of fertilizer applied (60, 60, 80 kg/ha N-P₂0₅-K₂0) + Fulan application interacted positively (P < 0.05) resulting in significant yields (32 and 30%) over the control treatments in mound and ridged bed types, respectively. The same treatment resulted in the highest marketable weight of yam which was 61% over ridged bed type + fertilizer applied at 60, 60, 80 kg/ha N-P₂0₅-K₂0 without Fulan application. Cracks were significantly low in Fulan treated tubers. The outstanding reduction in cracks was recorded in mound + F4 + Fulan which were 92% less than mound bed type only (control) tubers. Additionally, Fulan application suppressed nematode densities. The remarkable suppression in Meloidogyne incognita and Pratylenchus coffeae occurred in ridged bed type + fertilizer applied at 45, 45, 60 kg/ha N-P₂0₅-K₂0  + Fulan treatment which was 93% over mound bed type without fertilizer and Fulan application and 97% over mound bed type + fertilizer applied at 60, 60, 80 kg/ha N-P₂0₅-K₂0  without Fulan application, respectively. Ridged bed type appeared to be the better plant bed type alternative since the highest yield and nematode suppression were recorded in that option; besides, ridging presents drudgery saving intervention which farmers could exploit.

Key words: Dioscorea species, drudgery saving intervention, Fulan, plant bed type.