EFFECT OF POTASSIUM FERTILIZATION AND HUMIC ACID APPLICATION ON PLANT GROWTH AND PRODUCTIVITY OF POTATO PLANTS UNDER CLAY SOIL

Abstract

This experiment was carried out during the two successive summer seasons of 2008 and 2009 at Private Farm in El-Mahala El-Kobra region Ghrabia Governorate, on potato plant cv. Diamant to study the effect of potassium rates (0,50 and 100 kg K2O/fed) and humic acid as soil application (0, 2 and 4 kg/fed. as humate potassium) as well as their interactions on growth, nutrition status and productivity of potato under clay soil. Application of 100 kg K2O/fed. was the superior treatment for enhancing dry weight of straw and tubers, percentage of N,P and k and total uptake by plant as well as total yield/fed. Treated of potato plants with humic acid at 4 kg/fed. gave the maximum values of plant growth and plant nutritional statues as well as yield and its components with significant differences with 2 kg / fed. with respect to N,P and K (%) and yield and its components. The best interaction treatment for increasing yield and its components was obtained by fertilization of potato plants with 100 kg K2O / fed. and treated of plants with 2 kg /fed. humic acid.