EFFECT OF BORON AND IRON APPLICATION ON THE YIELD AND YIELD PROPERTIES OF COWPEA (Vigna unguiculata L.) PLANTED AT DIFFERENT SOWING TIMES

Abstract

Cowpea (Vigna unguiculata L.) is an important grain legume which is grown for food and feed. It has been employed as both a nutritious animal feed and a human nutritional component. Unavailability of essential micronutrients is a major constraint for cowpea growth, nodulation, and pod yield. In this context a two-year experiment was conducted to assess the effects of iron (Fe) (control-1-2-4 kg da1) and boron (B) (control-150-300-600 g da1) on the yield and yield properties of the cowpea (Vigna unguiculata L.) planted at different sowing times (15 May-30 May) in Ordu, Turkey region. The experiment design was split-split plot in randomized complete block design with 3 replications. The result revealed that combined use of seed treatment with Fe, B and sowing time significantly (P & LE;0.01) enhanced the yield and yield attributes of cowpea. Although all the properties examined showed positive increases with Fe and B applications, decreases occurred at 600 doses of boron. Even lower results were obtained for some properties than the control. In FexB interactions, results are higher than the effects of the applications alone, but the 600 dose of boron prevents the positive effect of iron alone. When the results obtained were examined, it was seen that the best results were obtained from the interactions of 2 kg da 1 Fe dose, 300 g da1 B dose and May 15 sowing time.