Comparative rice yield and economic advantage of foliar KNO3 over soil applied K2SO4.

A field experiment was conducted at Kala Shah Kaku to study the effect of foliar application of potassium nitrate (KNO3) in comparison to soil incorporated potassium sulphate (K2SO4) on the growth and yield of fine rice "Super Basmati". The treatments were control, i.e. soil application of K2SO4 @ 70 Kg ha(-1) (T-1), foliar application of KNO3 @ 0.5% solution (T-2), foliar application of KNO3 @ 1% solution (T-3), foliar application of KNO3 @ 1.5% solution (T-4) and foliar application of KNO3 @ 2% solution (T-5). Foliar KNO3 application @ 1.5% and 2% solutions increased paddy yield by 5.74% (4.97 t ha(-1)) and 10.85% (5.27 t ha(-1)) against that of soil incorporated K2SO4 (4.7 t ha(-1)). Significant increase in number of tillers (m(-2)), thousand grain weight, biological and paddy yield was recorded with foliar KNO3 @ 1.5% and 2% over soil applied K2SO4; however, non-significant differences were found on plant height, panicle length, and grains panicle(-1). Foliar KNO3 @ 1.5% and 2% solutions resulted in net returns of Rs. 14,828 and Rs. 23,804 ha(-1), respectively.