Effect of Different Levels of K on Growth Performance of Immature Oil Palm in Devithurai Estate Sri Lanka

Abstract

Initial growth of oil palm in the field highly depends on quality of the planting materials, management practices and availability of macro and micro nutrients. Failure in supply of these nutrients badly affects initially the vegetative growth performance and finally the yield. An experiment was initiated to investigate the available nutrient levels on plant growth performance at Devithurai estate. Field trial was conducted with RCBD design and six treatments of different K levels and constant levels of N, P, and Mg with four replicates (T1=0, T2 =60, T3 =90, T4 =120, T5 =150, T6 =180 of K₂O/Kg/Ha/Ye).  Soil nutrient levels and plant growth performances were recorded and data were analyzed with Minitab statistical tool. Results revealed that higher the soil Potassium level plant height was also high (recorded up to 263 cm) although the recommended soil Potassium level is 0.3 cmol/Kg for the Oil Palm.  This trial shows rather very low levels of soil K in four replicates in T1 (0.21, 0.18, 0.34 and 0.19coml/Kg respectively) except the replicate three (0.34cmol/Kg). It was shown that there were clear increases in number of fronds in the third replicate. This could be attributed to the fact of initial high soil K level in the soil with periodical application of fertilizer treatments to the trial plots. All the four replicates were showing very good soil available P levels at the initial stage of the trial. The recommended soil Mg level is 0.3cmol/Kg for Oil Palm. In this trial Mg level is very low in all the four replicates. It is concluded that the initial soil nutrient levels especially K is playing a significant role in young Oil Palm growth (P>0.05). Therefore periodical application of fertilizer is a must for better performance of this crop.