| Studies on biological yield and harvest index in durum
wheat* A. KUMAR and R.K. CHOWDHURY Department of Plant Breeding, Haryana Agricultural University, Hisar, India. The biological yield refers to the total dry matter accumulation of a plant system. Improved harvest index represents increased physiological capacity to mobilize photosynthates and translocate them into organs having economic yield. Since economic yield is only a fraction of dry matter produced, the harvest index forms a useful measure of yield potential. Accordingly, the present study was taken up to study the biological yield and harvest index in durum wheat over three environments. Material and Methods The present study was conducted on 45 diverse genotypes of durum wheat (Triticum durum Desf.). All the genotypes were grown in randomized block design consisting of three replications in three different environments. The environments were, i) Normal sown, high fertility and irrigated (E1), ii) Medium fertility and restricted irrigations (E2) and ii) Rainfed and low fertility (E3). The data were recorded for various characters and the correlation and path coefficients were obtained according to the standard formulae. Results and Discussion From the analysis of variance, the mean squares due to genotypes were found highly significant for all the eleven characters studied (flag leaf area, awn length, days to earing, plant height, tiller number, biological yield, grain yield, harvest index, grains per ear, spikelets per spike and 1,000 grain weight) indicating sufficient genetic variation among genotypes for all these characters. Considering the mean performance of genotypes for different characters studied in the three environments, it appeared that genotype V 45, R 6009, R 6011, R 6029, R 6032, CPAN 6048, CPAN 6035, WH 822, V 41, V 43 were good for grain yield in all the environments. These genotypes also showed expression of component characters viz., harvest index, tiller number and biological yild. Of the various component characters of grain yield, a few which may be positively associated with yield, often prove to be useful in selection. Hence the knowledge of such associations is valuable in planning effective and successful breeding programme. In the present study (Table 1), grain yield showed highly significant and positive correlations with biological yield, tiller number and harvest index (except in E3) and are in accordance with earlier reports in wheat. (KALTSIKES & LEE 1971 ; DE PACE et al. 1978 ; SIDU et al. 1976). Grain yield apperared to be weakly but positively correlated with plant height, grains and spikelets per spike and grain weight. Positive association between grain yield and grains per ear has also been reported by KALTSIKES & LEE (1971) and others in durum wheat. |
| * Part of M. Sc. Thesis submitted by the senior author to the Haryana Agricultural University, Hisar. |
| --> Next |