Effect of Foliar Application of Potassium on Yield, Drought Tolerance and Rain Water Use Efficiency of Toria under Rainfed Upland Situation of Assam

A field experiment was conducted during rabi seasons of 2011–12 and 2012–13 at the research farm of All India Coordinated Research Project for Dryland Agriculture at Biswanath College of Agriculture, Assam Agricultural University to study the effect of foliar application of potassium on yield, drought tolerance and rain water use efficiency of toria under rainfed upland situation of Assam. The experiment was conducted with 8 treatments (T₁: Control, T₂: 100% NPK (RDF), T₃: 100% N & P+ 75% K as basal, T₄: 100% N & P+ 50% K as basal, T₅: T₃+ 2% KCl spray before flowering, T₆: T₄+ 2% KCl spray before flowering, T₇: T₅+ 2% KCl spray at siliqua formation, T₈: T₆+ 2% KCl spray at siliqua formation) in a Randomized Block Design with three replications. Foliar application of potassium on growth and yield of toria revealed that application of 100% N&P + 75% K as basal + 2% KCl spray before flowering + 2% KCl spray at siliqua formation (T₇) resulted in highest grain yield (5.66 q/ha), straw yield (10.82 q/ha), Rain Water Use Efficiency (16.23 kg/ha mm⁻¹), net return ( 9341 ha⁻¹) and B:C ratio (2.15).