Effect of Different Potassium Rates and Hybrid Maize Varieties on the Grain Yield Under Field Condition at South Sulawesi, Indonesia

Potassium (K) is an essential nutrient for plant health and play critical roles in controlling protein metabolism, enzyme activity and various metabolic processes. In order to investigate the effect of different potassium rates and hybrid maize varieties on the yield and yield components of maize, an experiment was carried out at the Bajeng Experimental Station, Indonesian Cereals Research Institute, Gowa, South Sulawesi, from May to September 2017. The level of K on site of the experiment is 0.26 mg kg^-1. The potential grain yield of three hybrid maize varieties has different. Nasa-29 has potential grain yield (13.5 t ha^-1), Bima-20 (12.8 t ha^-1) and Bima-4 (11.7 t ha^-1). The experiment was laid out in randomized split plot design with three replications having a plot size of 9 m x 6 m with planting density 75 x 25 cm. The main plot was provided with six different levels of potassium i.e. 0, 20, 40, 60, 80 and 100 kg K₂O ha^-1. The sub plot consisted of three hybrid maize varieties i.e. Nasa-29, Bima-20 and Bima-4. The interaction of different levels of potassium and hybrid maize varieties significantly affected to maize cob diameter, weight of 1000 grains, and grain yield. The application of potassium at the rate of 60 kg K₂O ha^-1 for Nasa-29 variety produced the highest grain yield (11.33 ha^-1) under field condition at the agro-ecological of Gowa, South Sulawesi.

Keywords: Grain yield; Hybrid maize; Potassium level; South sulawesi