Abstract:
The objective of the research was to determine the effect of watering
frequency on the growth of seedlings in the three genotypes of Jatropha (Jatropha
curcas L.), and the effects of watering frequency on seedling phase to the plants
growth in the field. This research was conducted in the greenhouse, in the soil
physics laboratory, and in the experimental field of Cikabayan, IPB Dramaga,
Bogor, from March to December 2010. First experiment was used Randomized
Complete Block Design (RKLT) with 2 factors, namely the frequencies of watering
(5, 8, and 11 watering days) and genotypes of Jatropha (Biak, Bengkulu, and
Bogor). Second experiment was used Randomized Complete Block Design with 1
factor, namely genotypes of Jatropha from the first experiment. The result of
green house experiment showed that the watering frequency were affected plant
height at 2 - 12 weeks after treatment (WAT), the number of leaves at 2 WAT, and
the diameter of stem at 4 - 12 WAT. The genotypes only affected on the diameter
of stem at 4 - 12 WAT and the number of leaves at 2 WAT. The interactions
between watering frequency and genotype treatments was no effect on all
variables. The three genotypes of Jatropha were observed (Biak, Bengkulu, and
Bogor) had almost the same resistance to frequency of watering treatment. The
best watering intervals at three genotypes of Jatropha in this research was the
frequency of 8 watering days. The result of field experiment showed that the
genotype treatment only affected on the diamater of stem at 2 WAT. The impact of
watering frequency on all three genotypes of jatropha were not visible on plant
growth in the field, both of vegetative and generative phases.
