In India a 3-years trial on potato (Solanum tuberosum L.) was carried out to study the effect of foliar potassium nitrate application on potato yield. On a coarse loamy, non-calcareous soil the application of nitrogen (urea) or foliar KNO3 application showed little effect on potato yield in the absence of potassium application. In presence of potassium, a statistically significant increase in the tuber yield was obtained with increasing level of nitrogen and foliar application of KNO3. Among the 2 foliar fertilizers, i.e. KCl (MOP) and KNO3, potassium nitrate resulted in the highest yield at concentration of 2% which was superior to 1%. The increase in yield levels is related to the increase in the size of the tubers.
Brar, M. S. and N. Kaur. 2006. Effect of soil and foliar applied potassium and nitrogen on yield of potato (Solanum tuberosum) in alluvial soils of Punjab, India. The Indian Journal of Agricultural Sciences, 76 (12): 740-743.