THE EFFECT OF IRRIGATION PERIOD AND PLANT DENSITY IN SOME QUANTITATIVE CHARACTERS FOR VARIETIES OF COWPEA (Vigna sinensis L.)

Abstract

This study was conducted in a private field, Bani Saad district/ Diyala governorate, during 2013 growing season to study the effect of irrigation intervals and plant density on some quantitative traits of three cowpea cultivars yield. The experiment included three factors namely: Three cowpea cultivars (Black Eye, Ramshorn and Ramshorn H5) three irrigation intervals (every two, four and six days) and two planting densities (one and two plants per hole). The experiment was carried out in accordance to strip split-split plots using RCBD. Results can be summarized as follows: No significant differences were showed in studied characters of all cultivars, were as irrigation intervals differs from each other significantly that irrigation every two days treatment gave the best pod length, diameter and total yield. Planting densities didn't revealed a significant differences. Interaction of cultivars and irrigation intervals showed that plants of Ramshorn and Black Eye cultivars irrigated every two days gave the highest yield per plants (8.130 and 8.182 ton h-1 respectively), on the other hand Ramshorn H5 plants irrigated at two days interval had the superiority in pod length 15.45 cm, Plants belonged to. Cultivars irrigated every 4-days gave the best number of seeds per pod 7.718 seeds. Interaction of cultivar with plants density showed that Black Eye cultivar plants planted with two plant per hole gave the pest total yield 10.02 ton h-1. Overlap between plants densities and periods of irrigation was significance as it gave the plants on the intensity of two plants density and irrigation intervals significantly affected many characters, where two plants per hole interaction irrigated every two days the pest yield 10.732 ton h-1, fur ther more one plant per hole density irrigated every two or four days intervals gave the highest pod 15.72 and 15.14 cm, respectively. Plant density of one plant per hole irrigated every four ore two days gave the best number of seeds per (7.633 and 7.348 seeds pod-1 respectively). The triple overlap revealed that Black Eye plants irrigated every two and four days and planted at two plants per hole gave the best yield 11.116 and 10.698 ton h-1 respectively.