The Effect of Fertilizer and Irrigation on Yield and Quality of Rubber (Hevea brasiliensis) Grown in Chanthaburi Province of Thailand

Abstract

The experiment on effects of fertilizer and irrigation on yield and quality of rubber (Hevea brasiliensis) grown at Chanthaburi province is an on-farm research conducted at the Rubber Plantation of Sindane Thai Rubber Co, Ltd. The objective of the experiment was to investigate the effect of irrigation and fertilizer on yield and quality of rubber. Experimental design used was a split plot with three replications, having irrigation and non irrigation as main plots and three formulas of NPK fertilizer of 15-7-18, 30-5-18 and 23-5-18 as subplots factorially arranged within each main plot. The trial was conducted on the clay loam soil of Klongluk series having the pH of 5.0 with 1.6% organic matter, 80.9 and 134 ppm of P and K respectively. The result of the experiment revealed that irrigation treatment increased the yield per tree per tapping, monthly production and also total rubber production per year. Latex yield also increased as the result of irrigation treatment. Under non-irrigation, the percentage of dry rubber content (DRC) was higher than those of irrigation treatment. Percentage of DRC was negatively correlated with both rubber yield and latex yield only under non-irrigation treatments. Result of latex diagnosis analysis showed that sucrose and total solid content (TSC) of samples were not affected by irrigation and fertilizer treatments. Inorganic phosphate (Pi) increased in the irrigated plot than those of non-irrigation but was not significantly differed (P>0.05) among others. Thiol content in latex samples showed the significant different (P<0.05) between irrigated and non-irrigated plots. Girth of rubber increased as the result of irrigation application while the percentage of tapping panel dryness (%TPD) was higher in non-irrigation treatment. The result of this study did not showed the effect of fertilizer treatments in any of the parameters measured. It may be possible that it would take a longer time than the experimental period before the effect of fertilizer will be pronounced.