EFFECT OF PLANTING DATE AND PLANT DENSITIES ON COWPEA PRODUCTIVITY GROWING AT NEW VALLEY.

Abstract

Two field experiments were carried out in the Desert Research Center (D.R.C.), Agricultural experimental station at El-Kharga, New Valley Governorate, during two growing seasons of 2005 and 2006, to study the effect of planting dates and plant densities on productivity of cowpea (Vigna Sinensis L., cv. Kareem 7). The soil texture was sandy clay loam containing 2.04 % organic matter, pH 8.3 and EC 4.4 dS/ m. Underground water was the source of irrigation its pH was 7.3 and EC 1.08 dS/ m. Combined analysis of the two seasons data showed the follows: 1- Planting on 15 March as well as the density of 224000 plants / fed. each gave the highest significant values in plant height, number of branches / plant, fresh and dry weight / plant, fresh and dry forage yield/fed, number of pods / plant, number of seeds / plant, seed weight / pod, 100-seed weight, biological yield, seed yield, straw yield and chemical composition such as, nitrogen, phosphorus, potassium, total carbohydrate, crude protein contents and TDN % in seeds and straw of cowpea plants. 2- The interaction between planting date and plant density had a significant effect on plant height, number of branches / plant, fresh and dry weight / plant, fresh and dry forage yield/fed, number of pods / plant, number of seeds / plant, seed weight / pod, 100-seed weight, biological yield, seed yield and straw yield. The highest values were obtained by planting on 15 March with the density of 224000 plants / fed. while the reverse were obtained by planting on 15 February with 84000 plants / fed. Planting on 15 March increased all chemical characters i.e., nitrogen, phosphorus, potassium, total carbohydrate and crude protein contents of cowpea plantsunder planting density of 224000 plants / fed., except TDN % of straw which gave the highest value by planting in1st March with 224000 plant / fed.