Abstract

Oil Palm was considered as a high yield oil crop per unit of cultivation area. Applying the right fertilizer rate will help to increase yield production. Applying fertilizer at excessive rates can impact production costs, while using fertilizer at lower requirement rates affected to decreased yield in low yields. Leaf greenness value could be indicated the chlorophyll quantity, which affected to the efficiency of photosynthesis, growth, and yield. This study aimed to investigate the correlation between leaf greenness and yield obtained from three rates of fertilizer application in 13-year-old Suratthani 2 oil palm in Rangsit soil series. A randomized complete block design experiment (RCBD) with four treatments in three blocks was conducted: (1) application of chemical fertilizer 20-8-20 at the rate of 7.50 kilograms per tree per year, (2) application of chemical fertilizer 20-8-20 at the rate of 11.25 kilograms per tree per year, (3) application of chemical fertilizer 20-8-20 at the rate of 15.00 kilograms per tree per year, and (4) no fertilizer application for control. The data was collected by measuring leaf greenness was collected by selecting at the seventeenth leaf to measure with a chlorophyll meter (SPAD) at 6 months after fertilizer application. Yield data was collected every 15 days per harvest cycle and oil palm bunches were weighed. The weight of bunch and bunch number of each plant were recorded to calculate the average bunch weight and total weight for one year. The results showed that there was no significant difference in yield and leaf greenness among the three fertilizer rates. Additionally, there was no correlation between leaf greenness and yield.