RESPONSE OF POTATO PLANTS TO POTASSIUM AND MICRONUTRIENT FERTILIZATION

Two field experiments were conducted on sandy soil at El-Sharawy Village in EL-Bostan area, Noubaria region,Elbeheira Governorate (Latitude 30° 43' 22.01" N, Longitude 30° 16' 44.50" E), Egypt, during two successive winter seasons of 2013/2014 and 2014/2015 to study the effect of K2O levels i.e.(50, 75 and 100 % of the recommended rate 96 kg K2O/fed) along with foliar spraying with 1% K2O(2% K-sulphate) and/or mixture of Fe(150ppm), Zn(75ppm) and Mn(75ppm) on the growth, productivity, yield characters and quality of potato plants cv. Spunta.The results showed that plant height, foliage fresh and dry weight/plant, total yield, tuber number and yield per plantwere affected by K supply. Raising K level up to 96kg K2O/fed significantly increased the above mentioned vegetative growth parameters and total yield. Tuber yield and quality of potato plants were significantly higher when soil and foliar application of 1%K2O and /ormicronutrients were combined. The best results were achieved with foliar application of 1%K2O and micronutrients together with a basal fertilization of 96 kg K2O/fed. Similarly, macronutrients (N, P and K) and micronutrient (Fe, Zn and Mn) content in tubers recorded the highest valueswhen soil and foliar application were combined.The interaction between foliar application of 1% K2Oand micronutrientscombined with 72 or 96 kg K2O soil application producedsignificantly high vegetative growth characteristics, tuber yields and quality of potato plants with no significant difference between the two rates 72 and 96 kg K2O.