Study of planting media and nutrition concentration on growth rate and yield of Lettuce (Lactuca sativa L.) in NFT hydroponic systems

Abstract

Lettuce (Lactuca sativa L.) is a vegetable whose commercial value is quite good and the demand for lettuce has increased, including from hydroponic results. The use of rockwool planting media in hydroponics is often not available when needed and is expensive. Therefore it is necessary to study of using local planting media, such as: coconut fiber and rice husk charcoal as a replacement of rockwool planting media and whether the increased concentration of nutrients given to the planting media affects the rate of plant growth and yield of lettuce. The purpose of this research to study are interaction between planting media and nutrient concentrations (AB Mix) on the growth and development rate of plants, as well as the yield of lettuce hydroponically with the NFT system. The research was arranged in factorial with two factors using a Split Plot Design. The the main plot is AB Mix nutritional concentration (K) consisting of 3 levels (600 ppm, 900 ppm and 1200 ppm), while the subplot is a planting media (M) consisting of 3 treatment, namely: Rockwool, Coconut Fiber, and Rice Husk Charcoal. The results showed that the combination treatment of rice husk charcoal planting media and AB Mix concentration of 1200 ppm (M3K3) produced the best growth and increased the fresh weight of lettuce plants by 447,54% compared to the combination treatment of rockwool media and AB mix concentration of 600 ppm (M1K1). Rice Husk Charcoal planting media increases the growth rate of plant length and leaf area respectively by 26% and 81,54% compared to rockwool planting media. AB Mix concentration of 1200 ppm gives the best response and increases the growth rate of plant length and lettuce leaf area respectively by 367,5% and 165% compared to the concentration of 600 ppm.