Staggered Sowing and Manuring Effects on Hybrid Sunflower (Helianthus annuus) during Rabi Season in Coastal Bengal

Field experiments were conducted during the Rabi seasons of 2018-19 and 2019-20 at Regional Research Station (CSZ), BCKV, Kakdwip, South 24-Parganas, West Bengal to assess the variation in growth and yield determining traits of hybrid sunflower (cv. Sunbred 275) under staggered sowing and manuring practices. The field trial was arranged in a split-plot design with four sowing dates (S1 = November 30, S2 = December 07, S3 = December 14 and S4 = December 21) in main plots and three manuring practices (M1 = 100% RDF i.e., 80:40:40 kg N:P2O5:K2O kg ha-1), M2 = 75% RDF + vermicompost @ 5 t ha-1 and M3 = 75% RDF + farm yard manure @ 10 t ha-1) assigned to the sub-plots, each replicated thrice. Growth attributes, yield components and seed yield (2.14 t ha-1) of sunflower were found to be significantly higher in early-sown crop (November 30). Subsequent delay in seed sowing beyond November 30 caused poor vegetative and reproductive growth of crops and thereby resulted in poor growth attributes, yield components, seed oil content, seed yield and stover yield of test crop. Application of 100 % RDF gave significantly higher growth attributes, yield components, seed oil content (38.6 %), seed yield (1.91 t ha-1), stover yield (6.07 t ha-1) and economic benefit (B:C ratio of 1.62) of sunflower. However, the treatment 75% RDF + 5.0 t vermicompost ha-1 gave at par results for seed oil content (39.7%), seed yield (1.86 t ha-1) and stover yield (5.96 t ha-1). Seed sowing on November 30 with 100% RDF may be recommended for maximizing sunflower production during Rabi in coastal West Bengal. However, considering the need to reduce fertilizer consumption and maintain soil health, the treatment comprising 75% RDF + 5.0 t vermicompost ha-1 would be beneficial for sustainable sunflower cultivation in the region.