ABSTRACT
The study was conducted at University of Ilorin Teaching and Research Farm of the
Faculty of Agriculture, in the Southern Guinea Savanna Zone of Nigeria, during
2010/2011 raining season.
The study was carried out on the effect of population density on growth and yield
of Jatropha curcas. A field experiment was carried out using, Randomized Completely
Block Design. Treatments were randomly allocated to each block and each treatment
was replicated three times. The treatments were obtained by using 5 plant populations.
The population used include: the highest population of 10,000 plants per hectare at 1m
x 1m spacing, followed by 2500 plants per hectare at 2m x 2m spacing, 1,111 plants per
hectare at 3m x 3m spacing, 650 plants per hectare at 4m x 4m spacing, and 400 plants
per hectare at 5m x 5m spacing. Data were collected on the following growth
parameters: survival percentage, number of buds per plant, bud length, plant height,
number of leaf per plant, total plant biomass, and physiological growth indices, and yield
parameters.
Results showed that survival percentage increased with decreased in population
densities, and there was a significant difference at 28 days after planting, although all
the population attained a 100% survival at 35days after planting. From the analysis of
variance, the difference in mean values of the plant height was significant (p< 0.05)
during the later stage of the vegetative growth.
The bud length, the number of leaves per plant, plant weight, and the root
lengths, were higher at high population densities, and these growth parameters
contribute to the yield of Jatropha curcas at high densities on hectare bases. Therefore
the yield was significantly higher, at high population densities than at low population
densities. In this case, all the parameters have significant (0.05) differences between
their mean values.