Title : Screening ten varieties of cowpea (Vigna unguiculata (L.) Walp.) for yield and insect pests resistance in Sapele, Delta State, Nigeria
Abstract:
Two field experiments were conducted during planting seasons of 2022 and 2023 in Sapele rain forest zone of Delta State in Nigeria to screen ten cowpea varieties comprising of eight new varieties and two old varieties as check. The varieties are IT90K – 227 – 2, Ifobwell/01, IT99K – 216 – 24 -2, Modupe, Ife 98 -14, IT93K – 573 – 5, IT 89KD – 391, Ife 98 -12, Ifebrown and Erusu. The experiment was laid out in a randomized Complete Block Design (RCBD) consisting of ten treatments (varieties) in three replicates. The parameters assessed include germination percentage, number of leaves, plant leaf area, vine length, plant branches, days to 50% flowering, days to 50% podding, number of pod per plant, number of seeds per pod, unshelled dry pod weight, as well as shelled seeds weight and percentage population of seven commonest insect pests associated with the cowpea varieties in the area. The study revealed that Ifobwell/01, Modupe ad Ife 98 – 12 had the best germination count while Erusu and Ife 98 -14, the lowest. In the planting season of 2022 Erusu, IT89KD -391, IT93K – 573 – 5, Ife 98 – 12 and Ifebrown recorded the highest numbers of leaves. During the planting season of 2023 however, Erusu, Ifebrown, Ife 98 – 12, IT90K -227 -2 and IT99K – 216 -24 2 recorded the highest number of leaves. The leaf area ranged from 119.62cm2 to 196.32cm2 with Ife 98 -12 and Erusu recording the highest and lowest respectively. The vine length was significant (P <0.05) among the varieties during the two cropping years. In 2022 planting season, vine length ranged from 115.7cm to 179cm with Ife98 – 12 and IT99K – 216 – 24 2 recording the longest and shortest length. During the 2023 planting season on the other hand, Ife98 – 12 and IT99K – 216 -24 – 2 maintained the longest and shortest length. There were marked differences in the number of days to 50% flowering among cultivars. It ranged from 56 to 73 days with Ife 98 – 12 and Modupe also recorded the shortest and longest days to 50% podding. There was significant difference (P<0.05) in the number of seeds per pod which ranged from 5 -13 seeds. Ife 98 – 12 and Modupe had the highest and lowest seeds per pod. Shelled seed weight during the 2022 planting season ranged from 0.05 to 0.69 t/ha with Erusu and Ifebrown being the lowest and highest yielders. The 2023 planting season shelled seed weight ranged from 0.17 to 0.69 t/ha with IT 99K – 216 – 24 -2 and Ife 98 – 12 being the lowest and highest yielder respectively. The study revealed that all the varieties were susceptible to insect pests attack. Ifebrown and Ife 98 – 12 showed more resistance to pests’ attack. Ifebrown and Ife 98 – 12 showed more resistance to pest attack than others. The study also revealed that Ife 98 – 12 had the overall best performance in most of the tested parameters and is therefore recommended in the area.
