Comparison of Fertilizer Formulations and Amount of Fertilizer Applications of Lactuca sativa L. ‘Grand Rapids’ Growing

Abstract

Lettuce or salad greens (Lactuca sativa L.), Grand Rapids variety, is a species of salad vegetable in the salad vegetable family that is commonly consumed. Provides high nutritional value, especially dietary fiber, calcium, vitamin C and vitamin A. Moreover, lettuce is economically important and has an increasing demand lead to the large number of lettuce planting. Farmers more often used chemical fertilizers than necessary. The objective of this research was to study the use of appropriate fertilizers for the growth of Grand Rapids lettuce. The experiment was carried out in a 2×2 factorial in CRD with 2 factors. The first factor was 2 fertilizer formulas, namely 15-15-15 and 14-4-24. The second factor was applying fertilizer at 2 levels, including 2 times (14 and 35 days after germination) and 3 times (14,21, and 35 days after germination) for a total of 4 combinations, 5 repetitions. Experimental data was recorded when the Grand Rapids lettuce plants were 50 days after germination. It was found that the fertilizer formulas 15-15-15 and 14-4-24 were significantly different (p ≤ 0.05) in canopy height and SPAD value, while the number of times of applying fertilizer at 2 and 3 times was not significantly different (p > 0.05) on the growth of salad vegetables. As for the interaction between the fertilizer formula and the number of times fertilizer was applied, it was found that there was a statistically significant difference per canopy height Chlorophyll content and fresh root weight.