Correlation Study of Temperature and Relative Humidity on the Growth of Jatropha curcas (Linn) Seedlings

The study was carried out to investigate the correlation between air temperature, relative humidity and the growth of Jatropha curcas seedlings. Sterilized river sand was used to raise the seedlings before being transplanted into polythene pots two weeks after germination. There were 42 polythene pots altogether, with pots arranged at an interval of 20m by 20m apart to enhance good aeration. Germinated seedlings were placed at the Agro-climatological station of the Forestry Research Institute of Nigeria (FRIN) for proper monitoring of climate effect. The climate parameter observed were temperature and relative humidity while the growth parameters of Jatropha curcas seedlings observed are stem height, stem diameter and leaf count. The experiment covered 15 weeks with 12 weeks of through observation, measurement and recording of data. Simple correlation coefficient (r) was used to determine the relationship between each of the climatic elements and the growth parameter of Jatropha curcas while the student t-test was used to test the significance of the relationship at 0.05 and 0.01 levels of significance. The mean of the measurement was used for the analysis. Results of the simple correlation coefficient (r) analysis revealed that there were a positive relationship between the relative humidity, temperature and the growth of Jatropha curcas with respect to stem height, stem diameter and leaf count. Further statistical analysis using student t-test showed that the relationship between the temperature and the growth of Jatropha curcas seedlings is insignificant at 0.05 and 0.01 level of significance. On the other hand, there is a significant positive relationship between the relative humidity and the growth of Jatropha curcas seedlings at 0.05 and 0.01 levels of significance. Finally, the study recommends that the temperature range between 30^o C – 34^o C and relative humidity (85-92%) should be used by the nursery workers, silviculturist and green house workers in raising Jatropha curcas seedlings in the green house. Besides, findings should be communicated to the stake holder’s so that it can be used for predictive purposes so as to avoid future seedlings failure with the misleading or misunderstanding of the required climate condition for proper and maximum production of Jatropha curcas seedlings in the tropics.