ORGANIC COMPOST AND MYCORRHIZAL INOCULATION ON PHYSIC NUT SEEDLINGS

Abstract

Physic nut species has shown great potential for biofuel production. This study aimed to evaluate the effect of inoculation with the arbuscular mycorrhizal fungus Glomus clarum and the application of organic compost on the growth and phosphorus (P) and nitrogen (N) absorption, in physic nut seedlings. A randomized experimental blocks design, in a 5x2 factorial scheme, was used, with the evaluation of organic compost levels (0 t ha^-1, 15 t ha^-1, 30 t ha^-1, 60 t ha^-1, and 120 t ha^-1) and presence or absence of Glomus clarum, with four replications. Physic nut seedlings inoculated with Glomus clarum presented, at levels of 15 t ha^-1 of organic compost, the lowest height (20%), 120 days after sowing. However, the basal diameter increased, at levels of 30 t ha^-1 (21%) and 120 t ha^-1 (33%) of organic compost, 60 days after sowing. Only in the treatment with Glomus clarum, physic nut seedlings showed increasing linear regression adjustment in the dry matter of stem (R² = 0.99), aerial part (R² = 0.98), roots (R² = 0.95), and whole plant (R² = 0.97), depending on the organic compost levels. Physic nut seedlings inoculated with Glomus clarum showed increases in P content of the aerial part of 93%, 37%, 57%, and 51%, for levels of 15 t ha^-1, 30 t ha^-1, 60 t ha^-1, and 120 t ha^-1 of organic compost, respectively. For the N content, such increases were 50% and 45%, at levels of 0 t ha^-1 and 60 t ha^-1 of organic compost, respectively.

KEY-WORDS: Jatropha curcas L.; biofuel; Glomus clarum; seedlings quality.