Studi Karakter Jarak Pagar (Jatropha curcas L.) yang Berpotensi sebagai Batang Bawah pada Lahan Marginal

Abstract

Grafting in physic nut (Jatropha curcas L.) is one of the methods to improve plant characteristics, such as the capability of the plant to grow better in marginal land. Grafting is performed by combining two distinct rootstock and scion. Therefore, the selection of Jatropha germplasm is required to be done in order to get the best rootstock. The aim of the study was to obtain the high quality of Jatropha rootstock that had the best performance of shoot and root growth characteristics on rocky and clay soil. The experiment was designed as a Completely Randomized Design (CRD) with two factors. The first factor was the type of soil, which were organic-sandy soil as a control (M0), rocky soil (M1), and clay soil (M2). The second factor was the various of the Jatropha accession (coded as S1, S2, S3, J1, J2, J3, B1, B2, B3, T, and JB accession). To determine the best Jatropha rootstocks, Principle Component Analysis (PCA) was employed based on all growth parameters. The result showed that all parameters, except chlorophyll b content, were influenced by the type of soil. Jatropha plants that were grown on M0 soil medium showed growth characteristics better than that of plants grown on the other soil media (M1 and M2). In general, M1 soil medium reduced growth parameters more than M2 soil medium, except the secondary root characters, which showed similar growth in both M1 and M2 soil media. Among accession of Jatropha showed different shoot growth characteristics, except shoot dry weight. On root growth characteristics, among Jatropha accession showed differences only in total primary root length, total primary root, and root dry weight. Only root dry weight parameter that was influenced by interaction of soil media and Jatropha accession. Based on PCA result it could be concluded that Jatropha S2, J3, B3, J2 and S1 accessions were the best rootstock candidate for rocky soil, while S2, J3, S1, JB, and J2 accessions were the best rootstock candidate for clay soil.