Effect of Time of Sowing and Spacing of Sunflower on Yield and Yield Attributing Characters in Non-saline Area of Patuakhali

The time of sowing and spacing affect the yield and yield-attributing characteristics of crops. An experiment was carried out at the Field Laboratory of the Agronomy Department of Patuakhali Science and Technology University, Dumki, Patuakhali during the period from November 2016 to April 2017 in order to evaluate the effect of sowing date and spacing on the yield and yield contributing characters of sunflower. The experiment was laid out in a split-plot design with three replications, where sowing time was assigned in the main plot and spacing was assigned as a sub-plot treatment. The experiment comprised four sowing times (30 November, 15 December, 30 December, and 15 January) considering factor A and six spacing (40 cm × 25 cm, 40 cm × 35 cm, 40 cm × 45 cm, 50 cm × 25 cm, 50 cm × 35 cm, 50 cm × 45 cm) considering as factor B. Sowing date and spacing influenced significantly almost all the characters studied. The crop was sown on 15 December at 50 cm × 45 cm producing the tallest plant of 137.36, 178.59, and 186.53 cm at 60, 75, and 90 DAS, respectively. The maximum leaf area (1172.00 cm2), the largest head (48.53 g), the widest head (18.13 cm), the maximum seed weight head-1 (57.51g), and the highest number of seed head-1 (872.94) were produced by sunflower when planted on 15 December at 50 cm × 45 cm plant spacing. The maximum stover yield (8.92 t ha-1) and the highest biological yield of 11.97 t ha-1 were produced by the 15 December planted crop at 40 cm × 25 cm spacing. The maximum 1000 seed weight (65.28 g), harvest index (29.31%), and seed yield (3.15 t ha-1) was obtained from the mid-planting date (15 December) at the 50 cm × 25 cm plant spacing. The planting time of 15 December and the planting spacing of 50 cm × 25 cm could be recommended for sunflower cultivation in the southern non-saline area of Bangladesh.