Abstract

Three-way factorial experiment in a randomized complete block design (RCBD) was designed and carried out to determine the effect of the interaction of potassium (K+) fertilizer, humic acid and irrigation period on wheat production. Wheat variety IPA 99 was planted using two rates of potassium fertilizer as KCl (0 and 150 kg K+/ha), two rates of humic acid (0 and 3 kg/ha) and three irrigation intervals (one week, two weeks and three weeks). The results showed that the interaction treatment of K and humic acid produced the highest number of internodes (7.00), for one and two weeks. However, for three weeks of irrigation intervals was (6.65). The highest plants were (145.00 cm) for two weeks of irrigation intervals. While the number of spikes/m2 was 145.67 for one week irrigation period which was not significantly different with two weeks irrigation intervals (143.33). The heaviest spikes and the highest grain yield were 6.93 g and 9.933 t/ha for two weeks irrigation intervals, respectively. The findings of the present study exhibited that using the combination of fertilizer (K × humic acid) led to reduce the irrigation requirement. Therefore, the results of this study recommend using the combination of (K × humic acid) to save water irrigation and to produce high grain yield.