Effect of fertilization and irrigation on yield and quality of sweet potato [electronic resource].

Includes references.

Three field experiments were carried out in the two successive summer seasons of 2003 and 2004 at the Agricultural Experimental Station, Faculty of Agriculture. Cairo University at Giza. These experiments aimed to study the ellect of soil fertilization with: I) Ammonium sulphate (20 % N) at rate of 0, 15, 30 and 45 Kg N Ifed. and foliar spray with micr{Jments at of rate of 1.5 g /L. f1) Cultivars (Mabrouka, loclil cultivar, and Beauregard) and potassium sulphate (49.5% K2O) at rate of 0, 50 )00 and 150 Kg K2O/fed. III) Cultivars (Mabrouka and Beauregard) and time otIast irrigation at 15, 30 and 45 days before harvest on the vegetative growth, yield and root quality of sweet potatoes .The results indicated that: Increasing N level resulted in increasing the vegctative growth characters, i.e., plant length, plant fresh weight and number of branches per plant. Significant increases were obtained also in the total yield and the roo quality, i.e., root length and weigh, due to increasing N level up to 30 Kg N/fed. Increasing N level resulted in higher dry malter and lower T.S.S., but did Eot have any influence on ascorbic acid or carotene contents. Total yield, in first season only at a rate of 0 and 15 Kg N/fed., was sigmficantly increased by foliar application with microelements. The root quality parameters and chemical content of roots were not affected by microelements fertilization. Increasing potassium applications by 0 to 150 Kg K,O/fed significantly increased plant fresh weight and number of branches per plan~ but had no effect on plant length. Total and marketable yield per fed. were increasing K rate. The potassium rate did not affect either the root length or . iam ter, but increased the root weight. Increasing K rate reduced the dry malter ncreased T.S.S. ascorbic acid, carotene and cWorophyll content. The short period between last irrigation and harvest resulted in increasing all characters of plant growth, total yield, root length, root weight, T.S.S., dry malter and carotene content but had no effect on root diameter and ascorbic acid in the sweet potato roots.

Summary in Arabic.