Influence of different light intensity on early growth of Jatropha curcas L. seedlings

Abstract

This study investigated the influence of different light intensities on the early growth of Jatropha  curcas seedlings. Forty (40) seedlings were randomly selected from the germinated seedlings in the nursery and arrayed under four different treatments (0, 20, 40 and 60% light intensity). The amount of light being received by each of the seedlings was regulated, using constructed wooden box covered with wire gauze (1 mm in size) and measured with photometer. The results on seedlings germination under different light intensity revealed that, the highest mean height (29.2±1.94 cm) was observed in seedlings covered with 60% wire gauze, while the least mean height (27.0±1.24 cm) was observed in the seedlings placed under control treatment (0% wire gauze). Also the highest mean seedlings girth (2.69 ± 0.15 mm) was observed in seedlings not restricted with light intensity (0% wire gauze), while, the least mean girth (2.27±0.08 mm) was found in seedlings restricted with 60% light intensity. The average number of leaves in the four treatments ranges between 6 and 7. The result on analysis of variance (ANOVA) conducted shows a significant effects (P 0.05). Conclusively, the finding has shown that, J. curcas seedlings required light for its survival, but at varying intensity, and it was noticed that the thicker the light regulator (wire gauze), the lower the amount of light being absorbed by the seedlings. Key words: Jatropha seedling, light intensity, wire gauze, influence survival.