| Effect of plant density on the growth and yield potential
of durum and bread wheat cultivars M.B. KUMBHAR and A.S. LARIK Department of Plant Breeding and Genetics, Sind Agriculture University, Tandojam, Pakistan. The development of the crop can be influenced by cultivation measures. A proper choice of cultivation measures contributes to high yields. One of these measures is the choice of proper spacing. Spacing influences root development, plant growth and yield. Too close spacing results in excess competition between plants and thus reduces yield. Too wide spacing do not make full use of the available soil surface and will not give an economic return (KUMBHAR & LARIK 1982). Total dry matter production per unit area of a plant species, when grown under constant environmental and cultural consitions, does not show much variation, but the large dfferences occur in harvest index (the ratio of economic yield to biological yield). Though the genetic constitution of a variety with high harvest index is of prime importance, the cultural methods especially the distance between and within the rows should be manipulated to such a limit as to give the highest economic returns (TOSUN & ESER 1975). The present study was there fore, initiated to determine the influence of plant densities on different quantitative traits of durum and bread wheat varieties. Material and Methods The effect of varying plant density on the growth and yield potentials of two durum and three bread wheat cultivars was investigated at the fields of Faculty of Agriculture, University of Ankara, during the year 1978-79. Durum wheat cultivars 66T12, Red 5132 and bread wheat cultivars Tosun 22, 66T1435, Bezostaya 1, were hand sown at five between row spacings (10, 15, 20, 25, 30 cm) and five within row spacings (1, 2, 3, 4, 5 cm) in four replications. A split-split-plot experimental design was employed with cultivars 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 in length. Plants from 1 m length of the central row were counted and harvested manually. Grain yield per m2, number of spikes per m2, number of seeds per m2, days to heading and harvest index were determined. Total fertile heads were counted from 1 m length of the central row after harvest and were threshed to obtain grain yield and converted to m2. Number of seeds per m2 were then calculated. Days to heading were counted from 1st May till 50% of the culms in each plot had visible spikes. Harvest index was calculated by dividing grain yield per m2 with its total dry weight and multiplying it with 100. |
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