|Author:||Mohamed, K. A. ; El-Lithy, R. E. ; Samia, M. E.|
|Book Group Author:||NA|
A field experiment was conducted in ARC, Egypt, during 2001 and 2002 to study the effects of withholding irrigation at 35 (I1), 49 (2), or 63 days after sowing or DAS (I3) on the performance of 8 soyabean cultivars (H15L5, H2L12, H15L17, H2L24, G22, G111, G35 and Clark). Water relations, yield, yield components and crop susceptibility factor were studied. The values of water consumptive use during the first season were 627.7, 606.1, 588.6 and 681.8 mm for withholding irrigation at stages of vegetative growth (35 DAS), flowering (49 DAS) and pod filling (63 DAS), and for the control (without withholding of irrigation), respectively. During the second season, the corresponding values of the water consumption were 659.1, 636.4, 618.2 and 715.9 mm. Withholding irrigation at the vegetative growth stage reduced the water consumptive use by approximately 8%, while withholding irrigation at the flowering or pod filling stages reduced water consumption by approximately 11 and 14%, respectively, over the control. Water utilization efficiency value (kg of seeds/mm applied water) was increased in G22 under with I1 and I4. The most efficient method for calculating soyabean water consumptive use in Upper Egypt was the modified Penman formula, followed by Penman Monteith. Plant height, number of branches per plant, number of nodules per plant, number of seeds per plant, seed weight per plant, 100-seed weight and seed yield per feddan were significantly increased by increasing water applied to soil up to 750 mm. G22 recorded the highest values for these parameters. The best interaction was found between the control irrigation treatment and G22. The highest reduction in seed yield (approximately 30%) was observed following the withholding of irrigation at the pod filling stage. The second most sensitive stage to water stress was the flowering stage (reduction in seed yield of approximately 20%). However, withholding irrigation at the vegetative growth stage resulted in an acceptable reduction in seed yield (approximately 5%). In general, the pod filling and flowering stages were the most sensitive to water stress for soyabean plants. G22 under the control treatment recorded the highest yield. G22 under I1, which was superior in terms of water utilization efficiency and seed yield/feddan, exhibited a reduction in irrigation water use of approximately 8% without a significant reduction in seed yield. [1 feddan=0.42 ha].
|Pages:||1441 - 1456|
|Journal:||Annals of Agricultural Science, Moshtohor|
branches, crop growth stage, crop yield, cultivars,irrigation, nodules, plant height, plant water relations, seed weight,seeds, soyabeans, varietal reactions, water use efficiency, yieldcomponents, Egypt, Glycine (Fabaceae), Glycine max, North Africa,Africa, Mediterranean Region, Middle East, Developing Countries, Glycine(Fabaceae), Fabaceae, Fabales, dicotyledons, angiosperms, Spermatophyta,plants, cultivated varieties, watering, soybeans, Field Crops (FF005)(New March 2000), Plant Breeding and Genetics (FF020), Plant WaterRelations (FF062), Plant Production (FF100)