Survival, growth and Cu accumulation by non-mycorrhizal and mycorrhizal Jatropha curcas L. seedlings or cuttings in a grassland and in mine tailing soils

Abstract

Jatropha curcas has been identified as an alternate source for biofuel, and thus requires immediate establishment of plantations in areas not utilized for food production such as in mine tailings sites. Screenhouse experiments were conducted to determine the survival, growth and copper (Cu) accumulation of non-mycorrhizal or mycorrhizal J. curcas seedlings or cuttings grown in oven sterilized grassland soil from Caliraya, Laguna and in mine tailing soils from Paracale, Camarines Norte and Mogpog, Marinduque. Grassland soil was sterilized in an oven for three days at 100 °C prior to use. Seedlings or cuttings were either uninoculated or inoculated with Mykovam or MineVAM mycorrhizal inoculants. Results show that Paracale soil supported the highest survival and best growth of seedlings or cuttings. In Mogpog soil, all seedlings died before two months except those inoculated with Mykovam while all cuttings died on the third month. Non-mycorrhizal seedlings did not survive in Caliraya soil while mycorrhizal inoculation increased seedling survival and growth. Cuttings did not respond to inoculation, probably due to low mycorrhizal infection (≤14%) as compared to seedlings (≤100%). Mykovam promoted higher survival and better plant growth than MineVAM because of its higher root colonization. Cu accumulation was higher in the roots of mycorrhizal plants and the lowest was in the leaves especially in the Mykovam-inoculated plants. In conclusion, Mykovam inoculated J. curcas grew better with higher survival rate than the control thus this imply that rehabilitation of grasslands in Caliraya, Laguna and mine tailing areas in Paracale, Camarines Norte can be done for its potential for biofuel production. However, field trials should be conducted.