Effect of Seedling Age and Transplanting Dates on Establishment and Yield of Sunflower (Helianthus annuus L.) in Coastal Region of Southwestern Bangladesh

Abstract

In the southwestern (SW) coastal region, timely sowing /planting of winter crops is often not possible due to the late harvest of Aman rice and excessive soil wetness. Recently, sowing and dibbling of winter crop seeds, including sunflower, in wet soil under zero-tillage conditions have become possible. However, it has been observed that late-established sunflower produces poor yields. Transplanting sunflower seedlings may be a potential technique for establishing the crop in the wet soils of this region. Therefore, a field experiment was conducted in a farmer’s field at Pankhali, Dacope, Khulna (AEZ-13) during the winter season of 2018–2019 to evaluate the effect of seedling age and transplanting date on the establishment and yield of sunflower. The experiment was laid out in a factorial Randomized Complete Block Design (RCBD) with three replications. The treatments consisted of two seedling ages (14-day-old and 21-day-old seedlings) and three transplanting dates (25 December, 5 January, and 15 January). The results indicated that, individually, 14-day-old seedlings performed better than 21-day-old seedlings, and earlier transplanting produced superior yield performance. The 25 December transplanting date resulted in the highest yield. The combined effect of seedling age and transplanting date showed that younger seedlings transplanted earlier produced the maximum seed yield, followed by younger seedlings transplanted on 5 January. Among the transplanting dates and seedling ages, earlier transplanting and younger seedlings produced approximately 54% and 25% higher seed yield, respectively, compared with later transplanting and older seedlings. The results of the present study revealed that transplanting 14-day-old sunflower seedlings between 15 December and 5 January can provide the best yield performance. Therefore, late harvesting of Aman rice may not be a major constraint to sunflower cultivation in the southwestern coastal region of Bangladesh.