Reação de pinhão-manso (Jatropha curcas L.) à Meloidogyne incognita

Abstract

The physic nut is widely used on oil extraction to a utilization of biofuels, beyond it is a resistant culture to drought. However, little is known about causes caused by nematode, in special the genus Meloidogyne which has a large geographical distribution, being Meloidogyne incognita one of the most important species. The aim of this study was verify the reaction of physic nut to M. incognita. Seeds of physic nut were sown in commercial substrate and the seedlings were inoculated with increasing concentrations of M.incognita: 0, 2.500, 5.000, 7.500 e 10.000 nematodes/plant (Initial Populations- Pi). After 60 days, analyzed the length of the Stem (LS) and Roots (LR), total plant height (TH), number of leaves (NL), fresh mass of Shoot (FMS) and of Stem (FMSM), dry mass of shoot (DMS) and Stem (DMSM), Root-knot Index (RI), number of eggs/SR (Final Population- Pf) and Reproduction Factor (RF=Pf/Pi). The data was submitted for variance analyses with the Tukey Test at the level of 5% of probability or analyses of the regression. The variables LS, LR TH, NL, FMS, FMSM, DMS, DMSM e RI didn’t show differences between the treatments. The Pf, after the concentration of 2.500 nematodes/plant (Pi) decreases according to the increase of the inoculum. The RF had the same result as the final population. The RF of M. incognita at the different concentration of inoculum was under than 1,0, showing that the physic nut is resistant to this nematode.