Evaluation of the Foliar Application of Nano Urea on the Performance of Rabi Sunflower (Helianthus annuus L.)

A study was conducted on clayey soils (vertisols) of southern Telangana zone (India) characterized by low soil organic carbon, low available nitrogen and medium available phosphorous (P) and high available potassium (K). The experiment involving seven nitrogen (N) management practices (T1 to T7) involving recommended dose of fertilizers (RDF) as soil application, varied rates of foliar application of nano urea (liquid) was laid out in randomized block design replicated thrice. All the treatments were supplied with basal 50% of soil applied urea fertilizer at the time of sowing except in T1 (No nitrogen application) treatment. Results revealed that application of recommended dose of fertilizers in three splits as soil application resulted into significantly highest growth, yield ( 1774 kg) and yield attributes of sunflower, and was found profitable (Benefit:Cost ratio = 3.47) over foliar application of varied rates of nano- urea spray. Foliar application of nano urea @ 2-4 ml L-1 in T3 to T7 treatments could significantly improve growth and yield of sunflower (by 546 to 744 kg) when compared to no nitrogen application treatment. However foliar application of nano urea showed significantly lesser growth and yield compared to soil application of RDF in three splits in rabi sunflower.