Application of two Potassium Fertilizer Sources with Different Proportionon Tomato (Lycopersicum esculentum L.) Yield and Quality.

Abstract

Potassium is one of the main nutrient absorbed by the plant in a large number. Currently, the main source of potassium in Indonesia is mostly from KCl,  while other sources of potassium fertilizer such as K2SO4 are rarely used by farmers because their K content is low. Even though K2SO4 contains Sulfur secondary nutrients which can improve the quality of various plants. A pot experiment was conducted to test tomato yield and quality in various application proportions of different potassium fertilizer sources. The experiment used randomized blocked design with three replications. Two potassium sources tried were potassium chloride (KCl) and potassium sulfate (K_­2­SO₄) in different proportions. The application dose of potassium fertilizer in each treatment was 200 kg K ha^-1 and one control treatment (without potassium). Therefore, there were six treatments. The research results indicated that: overall, potassium application was able to increase tomato yield and quality compared to control (without potassium application). Potassium application of 100 kg K ha^-1 from K₂SO₄+ 100 kg K ha^-1from KCl was able to increase fruit fresh weight per plant by 15.59%, fruit diameter by 2.72%, total sugar by 29.76%, Vitamin C by 10.41%, and fruit hardness by 25.00% compared to potassium application from KCl only. This suggests that to improve the quality of tomatoes, a combination of two types of potassium fertilizer is needed.

Keywords: potassium source, proportion, yield, quality, tomato