A field experiment was conducted to study the effect of seed treatment and foliar spray of nano DAP on plant growth and seed yield in RSFH-700 sunflower hybrid seed production at College of Agriculture, Bheemarayanagudi during rabi 2023-24. The experiment was laid out in RCBD consisting of nine treatments replicated thrice. The treatment consists of different levels of RDP along with seed treatment and foliar sprays of nano DAP. Among different treatments, 75% RDP+ Seed treatment with nano DAP @ 4 ml kg-1 + two foliar sprays of nano DAP at 35 DAS and 60 DAS recorded significantly higher plant height for female parent (125.01 cm and 156.46 cm at 60 DAS and harvest respectively), stem girth (4.93 cm and 4.98 cm at 60 DAS and harvest), head diameter (16.87 cm) hundred seed weight (4.83 g), seed filling per cent (80.71) and seed yield (904.66 kg ha-1) over remaining treatments and was followed by 100% RDP+ Seed treatment with nano DAP @ 4 ml kg-1. The lower yield parameters were recorded in seed treatment with nano DAP at 4 ml kg-1 + two foliar sprays of nano DAP at 35 DAS and 60 DAS. Based on the experimental results, it can be concluded that application of 75% RDP +seed treatment with nano DAP @ 4 ml kg-1+ two foliar sprays of nano DAP can be used for obtaining maximum seed yield which is most beneficial to seed producers.
