Pengaruh Frekuensi Penyiraman pada Fase Bibit terhadap Pertumbuhan Bibit dan Dampaknya pada Pertumbuhan Tanaman Jarak Pagar (Jatropha curcas L.).
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.