EFFECTS OF POPULATION DENSITY ON TILLERING AND YIELD OF WHEAT VARIETIES

Abstract

The experiment was conducted at the agronomy research field of Sher-e-Bangla Agricultural University, Dhaka during November 2018 to March 2019; to find out the effect of variety and population densities on the growth characters and yield parameters of wheat. The experiment comprised of two factors; Factor A: three improved wheat varieties viz. (i) V 1 = BARI Gom 30 , (ii) V 2 = BARI Gom 31 and (iii) V 3 = BARI Gom 32; Factor B: four plant population densities viz. D 0 = no thinning (control), D 1 = 100 plants m iii −2 , D 2 = 125 plants m = 150 plants m −2 . The experiment was laid out in Split-plot design with three replications. Variety was assigned in the main plot and plant population densities was in the sub-plots. The data were collected on plant height (cm), number of leaves plant −1 −2 and D 3 , number of tillers plant , dry weight (g m −2 ), crop growth rate (CGR), relative growth rate (RGR), weight of 1000seeds

(g), grain yield (t ha −1 ), straw yield (t ha −1 ), biological yield (t ha −1 ) and harvest index (%). It was evident from the results that morpho-physiological and yield-contributing characters of wheat were significantly influenced by variety and plant population densities either individually or in combination except relative growth rate (RGR). Experimental results indicated that plant height and dry matter weight increased up to harvest while number of leaves plant −1 and number of tillers plant −1 increased up to 60 DAS (days after sowing) and there after declined. CGR and RGR increased up to 45–60 DAS and then became steady. The combined effect of BARI Gom 30 along with 125 plants m −2 (V 1 D 2 ) population density showed significantly the tallest plant (78.31 cm) at harvest. The maximum dry matter weight (4394.00 g m −2 ) was obtained from the combination of the variety BARI Gom 32 with no thinning (V 3 D 0 ). The combined effect of BARI Gom 32 along with 125 plants m population density (V 3 D 2 ) produced the maximum number of leaves plant −1 −2 (18.70), tillers plant

(5.35),highest weight of 1000-seeds (55.44 g), grain yield (3.20 t ha −1 ), biological yield (4.55 t ha −1 ) which were positively supported by maximum value of harvest index (70.67 %) except dry weight m -2 which was highest at V 3 D 0 . The highest straw yield (2.80 t ha ) was observed from the combination of wheat variety BARI Gom 30 with no thinning (V 1 −1 D 0 ) treatment. The combination of wheat variety BARI Gom 32 with 125 plant m −2 was found to be the best treatment combination for wheat production.