YIELD AND YIELD RELATED PERFORMANCE OF COWPEA (Vignia unguiculata L.) VARIETIES TESTED AT DIFFERENT FERTILIZER USE UNDER IRRIGATION, CENTRAL GONDAR ZONE, ETHIOPIA

Inadequate quantity and quality feeds is the major constraints to livestock production in majority of smallholder farmers in Ethiopia. This necessitates the need to follow economically viable forage production. A study was conducted to evaluate the yield and yield related performance of cowpea (Vignia unguiculata L.) varieties under irrigation in 2017 and 2018 years. The experiment was laid down in a split plot design with randomized complete block design (RCBD) arrangement in four replications. There were two main plots of which one was planted with fertilizer and the other one without fertilizer for comparison and the sub plot treatments were eight varieties of Cowpea (Vignia unguiculata) (ILRI 9333, ILRI 9334, ILRI 11114, ILRI 12688, ILRI 12713, Kenkety, Black eye bean and IT92KD258-9). The data collected consisted of plant height (cm), number of branches per plant, forage biomass yield (t ha-1), dry matter yield (t ha-1), leaf to stem ratio, number of pods per plant, number of seeds per pod, grain yield (kg ha-1), thousand seed weight (g) and haulm yield (t ha-1). All data were subjected to analysis of variance procedures, with significance test at p<0.05. The results revealed that highest dry biomass yield (t ha-1) was recorded when Cowpea varieties ILRI 9334, ILRI 11114, ILRI 12688 and IT92KD258-9 planted with fertilizer. The highest haulm yield was obtained from Cowpea varieties ILRI 9334, ILRI 11114 and ILRI 12713 when planted with fertilizer and when ILRI 9334, ILRI 12688, ILRI 12713 and IT92KD258-9 Cowpea varities planted with out fertilizer. Cowpea varieties Kenkety and IT92KD258-9 produced higher grain yield compared to other varieties. Cowpea varieties ILRI 9333, ILRI 11114, ILRI 12688, ILRI 12713 and IT92KD258-9 when planted with and with out fertilizer; when variety ILRI-9334 and Kenkety planted only with fertilizer and also variety Black eye bean when planted with out fertilizer was found economically profitable. Therefore, based on the study results, planting Cowpea varieties ILRI 9334, ILRI 11114, ILRI 12688 and IT92KD258-9 with 100 kg ha-1 NPS fertilizer appears to be more preferable regarding biomass yield and were found potentially profitable.