Effect of Deficit Irrigation and Cultivar on Yield and Yield Components ‎of Soybean (Glycine max L.) in Heart Province- Afghanistan

In order to study effect of deficit irrigation and cultivar on yield and yield components of soybean, a field ‎experiment was conducted at the Ordukhan Agricultural Research Center, Heart Province-Afghanistan ‎‎(Geographical longitude: 62°11'29" east and geographical latitude: 34°20'35" north) during the cropping ‎season 2017-2018. The experiment was conducted in a split-plot arrangement based on randomized complete ‎block design with three replications. Deficit irrigation with three levels (70 (no stress), 90 (moderate stress) and ‎‎110 (severe stress) mm evaporation from class A evaporation pan) were considered as main plots and ‎cultivars with four levels (Glway, Stine, Hong and LD04) were allocated as sub plots. Analysis of variance ‎showed that the deficit irrigation had significant effect on number of pods per plant, number of grains per ‎pod, 100 grains weight, biological yield, grain yield and harvest index The effect of cultivar on all traits and ‎the effect of interaction between two factors on 100 grains weight were significant. The results showed that ‎the deficit irrigation at 110 mm evaporation (severe stress) cased of significantly reduced of all traits. The ‎lowest number of pods per plant (109.8 pods), number of grains per pod (2.4 grains), 100 grains weight ‎‎(15.27g), biological yield (7363 kg/ha), grain yield (2899 kg/ha) and harvest index (35.5%) were obtained in ‎‎110 mm evaporation. The means of traits at 70 mm (no stress) and 90 mm (moderate stress) evaporation had ‎no significant difference. The LD04 cultivar had the highest grain yield (3793 kg/ha), because this cultivar had ‎optimum yield components. Simple correlation coefficient of traits showed that the grain yield had positive ‎significant correlation with biological yield, number of pods per plant, plant height, number of grains per pod. ‎Based on, these results deficit irrigation up to 90 mm evaporation can be considered.‎