Influence of Climatic Factors and Soil Types on Seed Weight and Oil Content of Jatropha Curcas in Guangxi, China

The seed weight and oil content of accessions of Jatropha curcas collected from 21 locations in different climatic zones of Guangxi province, China and their correlation with climatic factors and soil types were analyzed. There were signi cant differences (P < 0.05) in 100-seed weight and oil content between locations. Maximum 100-seed weight was 71.0 in seeds collected from S21 and the minimum weight was 59.0g in S10. Oil variability ranged from 34.10% in S12 to 55.50% in S21. The seed weight and oil content of J. curcas in acid soil types were significantly higher than those in calcium soil types. Seed weight and oil content were positively correlated with the mean annual sunshine duration (Sa), the mean annual temperature (Tmean), mean minimum daily temperature of the coldest month (Tmin), mean maximum daily temperature of the warmest month (Tmax) and the mean annual evaporation (Ea) (p < 0.01), while were negatively correlated with altitude and the mean annual precipitation (Pa) (p < 0.01). The ecological requirements of J. curcas are more fertile soil and more humid and have a higher Tmin than its commonly believed ecological requirements, and therefore point towards cautious selection of plantation sites, especially in karst and subtropical regions. (C) 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of National University of Singapore.