SEASONAL GROWTH ATTRIBUTES OF WHEAT (Triticum aestivum L.) GENOTYPES IN RESPONSE TO MOISTURE REGIMES UNDER SEMI ARID ENVIRONMENT

A field experiment for the comparison among different wheat genotypes (Iqbal-2000, Chenab-2000, Aqab-2000) for its maximum yield potential in response to different moisture regimes, a randomized complete block design (RCBD) with split plot arrangement in triplicate run was carried out during the year 2006-07. Factors were: wheat genotypes (Iqbal-2000, Chenab-2000, Aqab-2000) in main plots and five irrigation levels I0= no irrigation (control), I1= irrigation at tillering, I2= irrigation at tillering + booting, I3= irrigation at tillering + booting + anthesis and I4= irrigation at tillering + booting + anthesis + milking in subplots. Results showed that maximum LAI was attained on 2 February and 4 March harvest and genotype Iqbal-2000 was superior compared to other genotypes. Irrigated treatments significantly increased LAI than control (I0) treatments at all harvest dates. Iqbal-2000 showed maximum CGR (32.69 g m^-2 d^-1) and LAD (319.42) compared with lowest CGR (25.49 g m^-2 d^-1) and LAD (278.50) given by genotype Chenab-2000 under I3 and I4 treatments throughout the growing season. Radiation use efficiency ranged from 17.58-18.27 DM MJ^-1 of intercepted radiation. Mean accumulated radiation interception (754, 736 and 784 MJm^-2) was assessed in genotypes (Iqbal-2000, Chenab-2000 and Aqab-2000), respectively but not significant effect on net assimilation rate. Genotype Iqbal-2000 and Aqab-2000 had highest TDM (21670; 21220 kg ha^-1) respectively while I4 (Irrigation at tillering + booting + anthesis + milking) had the highest TDM 22240 kg ha^-1 verses I0 (no irrigation) 18070 kg ha^-1. Aqab-2000 showed the highest grain yield (5458.78 kg ha^-1) as compared to Chenab-2000 (4536.71 kg ha^-1) whereas I4 (Irrigation at tillering + booting + anthesis + milking) produced more grain yield (6376.25 kg ha^-1) than all other irrigation treatments.