Respon pertumbuhan beberapa aksesi jarak pagar yang berpotensi sebagai batang bawah terhadap pupuk hayati pada media tailing tambang emas

Abstract

Physic nut (Jatropha curcas L.) is a potential plant for biofuels production. The objectives of this study were to analyze the germination of four physic nut accessions, seedling growth response to application of biofertilizer during seedling establishment, and plant growth response to application of biofertilizer in gold mine tailing media. Four consecutive experiments were carried out in green house and field laboratory used Block Randomized Design. The first experiment used three factors and three replications. The first factor was seed accessions of S1, J2, JB, and B3; second factor was pre-soaked in cow dung slurry and water; and third factor was germinated media on wet towel, compost, and soil. The second experiment used two factors and seventeen replications, and carried out in 900 g media per pot. The first factor was fertilizer treatment i.e with and without NPK, arbuscular mycorrhizal fungi (AMF), plant growth promoting rhizobacteria (PGPR), and combination of AMF and PGPR. The second factor of the second experiment was four plant accessions. The third experiment used two factors and three replications and carried out in 900 g media per pot. The first factor was fertilizer treatment i.e with and without NPK at recommended rate, 36 g of AMF, 10, 30, and 50 g of PGPR, and combination of 36 g AMF with each PGPR concentration. The second factor was four plant accessions. In the fourth experiment, all plant seedlings from second experiment were transfered to 15 kg of gold mine tailing and andosol soils. The results of first experiment showed that the pre-soaked seed with water and germinated in wet towel produced a higher germination rates than other treatments. The second experiment indicated that the AMF and combination of AMF with PGPR application increased vegetative growth and nutrient uptake of physic nut seedling. The third experiment showed that 30 g PGPR per pot produced best response of physic nut seedling growth. In the fourth experiment revealed that the AMF and combination of AMF with PGPR increased vegetative growth and nutrient uptake of plants. Accession of B3 had the best growth in both media tested, while JB grew better in andosol media. Gold mine tailing media reduced the growth response of physic nut up to 13.0% reduction.