An experiment was conducted at Agronomy Research Farm of The University of Agriculture Peshawar during summer 2016. Hybrids (WS-666, SB-92K97, and SB-909) and Potassium (K) levels (0, 40, 80, 120, and 160 kg ha-1) laid out in randomized complete block design with split plot arrangement. Hybrids were allotted to main plots and potassium levels to subplots. Sowing was performed on 10 July. Each experimental unit was 3m x 4.2m accommodating six rows at 0.70m distance from each other. All standard agronomic practices were constantly applied for each experimental unit. Hybrids and potassium levels significantly (P≤0.05) affected crop phenology (days to tasseling, silking, and maturity), growth (plant height) and yield traits (grains ear-1, thousand grain weight), biological and grain yield. Maize hybrids showed significant variation in phenology, growth and yield traits. As level of K increased from 0 to 160 kg ha-1 days to tasseling, silking and maturity decreased accordingly and more days for these traits were recorded in control plots. Similarly, with increase in K level plant height, grains ear-1, thousand grain weight, biological yield and grain yield also increased up to 160 kg ha-1 which showed a non-significant difference from 120 kg ha-1 K. The study concludes that sowing of maize hybrid SB-92K97 with application of K at the rate of 120 kg ha-1 gives higher maize return in terms of yield.

Keywords: sulphate of potash, hybrids, plant height, grains ear-1, thousand grain weight