Effects of parental lines and pruning on growth and biomass yield of inter-specific hybrids between Jatropha curcas and J. integerrima

Abstract

Selection of parents is an important role for inter-specific breeding of Jatropha to maximize the yield. The objective of this research was to investigate the effect of parental lines and pruning on growth and biomass yield of inter-specific hybrids between Jatropha curcas and J. integerrima. The total 325 plants of inter-specific hybrids between seven lines of J. curcas and three lines of J. integerima were evaluated in completely randomized design under the field condition for two years. Data were collected on growth and biomass yield traits during each year cycle. The effect of female and male lines were found for growth and biomass yield of offspring for both of after planting and after pruning. P5 line of J. curcas and Ji2 line of J. integerima gave the highest of growth and biomass yield in the hybrids. Moreover, P5 and Ji2 also gave hybrids with the lowest of wood moisture content and the highest of wood density. Pruning reduced size of branch and canopy, but increased leaf greenness and average leaf area of hybrids. Pruning effected to a little reducing of biomass yield. However, there were not affect to wood dry weight, wood moisture content and wood density. Thus, inter-specific hybrids of Jatropha might be harvested biomass for many years.