Evaluation of Some Local Cultivars of Dioscorea Rotundata for Yield, Agronomic Characteristics and Nematode-Pest Incidence

Abstract

Field experiments were conducted to evaluate some local varieties of Dioscorea rotundata for yield and pest incidence. Results showed that five cultivars were significantly different (p=5%) in agronomic characteristics which included percentage emergence and crop vigor. Yield attributes such as percentage stands count at harvest, number of seed tubers/plot, number of ware tubers/plot, tuber shape, tuber surface texture, yield of ware tubers/plot, total fresh tuber yield/plot were significantly different. The mean values of yield parameters showed Toryo cultivar gave the highest (14.33 Tuber/plot) yield both in ware tubers and total fresh tuber yield while Didie gave the lowest (14.33 Tuber/plot). Result on agronomic characteristics showed that crop vigor was highest in Toryo and Ayin at 12 weeks after planting. Visual observation showed mild damages caused by nematodes (Meloidogyne incognita and Scutellonema bradys), termites, yam beetles and yam mealybug on cultivars, especially Didie. Results of this study showed that Ayin, PNC, Didie, Toryo and Tilla are very good D. rotundata cultivars and therefore should be evaluated for food qualities.

Keywords: Cultivar, Nematode, Tuber, Vigor, Yam,