Abstract

Field experiment was carried out at Tamil Nadu Agricultural University, Coimbatore during summer and South West Monsoon seasons of 1997 to study the effect of NPK levels and seed setting treatments on the yield attributing characters of sunflower var. CO4. The yield attributing characters viz., head diameter, number of seeds head, seed filling percentage and 100 seed weight were significantly influenced by NPK levels. Whereas the seed setting percentage was influenced both by NPK levels and seed setting treatments. Application of N: P: K at 80:40:40 kg ha-1 was found to be superior in enhancing the yield and yield attributing characters in both the seasons. Among the seed setting treatments, application of 0.2 per cent borax with 2 per cent diammoniumphosphat (DAP) spray at ray floret opening stage was found to be superior in influencing the seed filling percentage in both the seasons.

Keywords: Sunflower, nitrogen, phosphorus, potassium, borax, diammoniumphosphate and seed setting