Effect of Chemical NPK, Organic and Foliar (High Potash) Fertilizers on Potato Growth and Tuber Yield

A field experiment was conducted in spring season 2017 in Babylon, Iraq, to study the effect of fertilization types (as individual or interaction) on growth and tuber yield of potato (Revera variety). The experiment included four levels of Nitrogen-Phosphorus-Potassium (15-15-15): (50, 100, 150 and 200 kg/ha), two levels of organic fertilizer (0 and 12 tons.ha-1 of fermented and decomposed palm leaves, and two levels of foliar fertilizer (control and spraying of 1% high potash soluble fertilizer (36% K2O, 15% N and 15% P2O5). Tuber seeds were planted on 16/01/2017. Randomized complete block design with three replications was used. The results showed that addition of high level of compound fertilizer significantly increased vegetative growth (plant height, number of leaves, leaf area and chlorophyll) and tuber yield to 32.060 t ha-1, compared to low level (50 kg/ha) which achieved 24.770 t ha-1. Foliar fertilizer only increased leaf area, whereas organic fertilizers caused a significant increases of plant length, leaf area and increasing tuber yield to 29.260 ha-1.