The impact of climatic conditions and tapping time on the yield of rubber (Hevea braziliensis) in mid-western Nigeria. (07)
Keywords:Rubber, Climatic factors, Minimum temperature, Maximum temperature, Rainfall, Latex yield
AbstractThe relationship between climatic conditions of tapping period and the yield of rubber latex in mid-western Nigeria, for 10 years (1992-2001) was examined. Data were collected from the three main rubber plantations in the mid-western region of Nigeria, namely, Rubber Research Institute of Nigeria, Iyanomo, Pamol Rubber, Oghara, and Integrated Rubber Plantation, Orhonigbe. Correlation and regression analyses were the statistical tools used to evaluate the relationships between climatic conditions and yield. Of the climatic elements, the highest correlation with yield was observed to be minimum temperature (r = 0.888) and maximum temperature (r = 0.44), and there was a negative correlation between rainfall (r = -0.58) and yield. In the regression model, minimum temperature with correlation of 0.89 explained 79% of the rubber latex yield, while rainfall was excluded from the regression model. Results from the time of tapping (1200-2300 h) showed that early tapping hours (0100-0500 h) produced the best yields, and 0200-0300 h produced peak yields. It was therefore recommended that the majority of the rubber tappers who start tapping between 0600-0800 h should begin to tap from 0100-0500 h for maximum yield.