ABSTRACT

A field experiment on “Response of sunflower (Helianthus annuus L.) to fertilizer levels and nano fertilizers” was conducted during the rabi 2023-24 in Kakol village, Haveri district, Karnataka, using a split-plot design with three replications. Main plots included fertilizer levels: RPP (M1), RPP – 25 per cent RDN (M2), and RPP – 25 per cent RDN and RDP (M3). Subplots involved foliar sprays: S1 (4 ml nano urea l-1 of water at pre flowering stage), S2 (4 ml nano DAP l-1 of water at pre flowering stage), S3 (4 ml nano urea l-1 of water at pre and 50 % flowering stage), S4 (4 ml nano DAP l-1 of water at pre and 50 % flowering stage) and S5 (Control).
Among various fertilizer levels, RPP (M1) recorded significantly higher dry matter accumulation (104.71 g plant-1 at 90 DAS), head weight (282.49 g plant-1), head diameter (19.1 cm at harvest), seed yield (1920 kg ha-1), stalk yield (3192 kg ha-1), net returns ( 89922 ha-1) and B:C (2.80). Among foliar sprays, application of nano DAP @ 4 ml l-1 water at pre and 50 per cent flowering stages (S4) achieved remarkably higher dry matter accumulation (102.13 g plant-1 at 90 DAS), head weight (272.93 g plant-1), head diameter (17.87 cm at harvest), seed yield (1855 kg ha-1), stalk yield (3143 kg ha-1) and net returns ( 84159 ha-1).
Among interactions, RPP along with foliar application of nano DAP @ 4 ml l-1 water at pre and 50 per cent flowering stages (M1S4) recorded significantly higher dry matter accumulation (111.54 g plant-1 at 90 DAS), head weight (307.35 g plant-1), head diameter (21.22 cm at harvest), seed yield (2089 kg ha-1), stalk yield (3539 kg ha-1), net returns ( 100765 ha-1) and B:C (2.96).