چكيده لاتين :
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 plants under
planting density of 224000 plants / fed., except TDN % of
