| Effect of plant population on yield components of Triticum
aestivum L. M.B. KUMBHAR and A.S. LARIK Department of Plant Breeding & Genetics, Sind Agriculture University, Tandojam, Pakistan Row width and seeding rate (plant spacing) traditionally have been considered important in winter wheat cultures (STICKLER 1961). Of the various important inputs for a successful crop of wheat the size of the plant population plays a crucial role in developing the yield potential of a variety. Spacing influences root development, plant growth and yield. Too close spacing results in excess competition between plants and thus reduces yield. Too wide spacing will not make full use of the available soil surface and will not give an economic return (MANGLICMOT et al. 1964). The present investigation was therefore, initiated to determine the influence of row width and seed rate (plant spacing) on different quantitative traits of winter wheat varieties . Material and Methods Present research was conducted on the agronomic research area of the Faculty of Agriculture, University of Ankara during the year 1978-79 with three winter cultivars viz., Tosun 22, 66 T1435 and Bezostaya 1 using five between row spacings (10, 15, 20, 25, 30 cm) and five plant spacings (1, 2, 3, 4, 5 cm). A split-split plot experimental design with four replications was used with varieties as main plots, row spacings as sub-plots and plant spacings as sub-sub plots. Each sub-sub plot consisted of three rod rows 1.5 m long. Obtservations on culm length, spike length, spikelets per spike, seeds per spike, 1000-kernel weight and yireld per spike were taken on 15 main stems selected randomly from 1 m length of the central row leaving border plants on both ends of the row. Results and Discussion Analysis of variance (Table 1) revealed highly significant (P>=.01) differences among cultivars for all the metrical traits except spikelets per spike. Likewise highly significant (P>=.01) effects were also observed for various row spacings and plant spacings. Details of main effects are depicted in Table 2. Row spacings and plant spacings had a significant effect on culm length. In all the cultivars culm length increased progressively with the increasing population density (Table 2) as a result of competition for light. Similar results were reported by PUCKRIDGE & DONALD (1967), CLEMENT & COLLINS (1976) and FEJER et al. (1979). KIRBY & FARIS (1970) reported that the early and vigorous elongation of the lower internodes of barley plant in response to high density is brought about by density induced changes in gibberellic acid (GA). |
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