COMPARATIVE EFFICACY OF FOUR PLANT LEAF EXTRACTS AGAINST ROOTKNOT NEMATODE (Meloidogyne javanica) IN JALINGO, NIGERIA

An experiment was carried out to compare the effects of four plant leaf extracts (Newbouldia laevis, Triumfetta rhomboidea, Piliostigma thonningii and Ageratum conyzoides) against rootknot nematode (Meloidogyne javanica) in 2017 and 2018 at Jalingo Nigeria. Eggplant cv Bello variety seedlings were transplanted into a nematode infested field and water extracts of these plant leaves were applied at transplanting and eight weeks thereafter. Data was collected and subjected to analysis of variance (ANOVA) and means were separated using SEM. The result showed that there was no significant difference among the extract treatments for almost all the parameters but highly significant difference between extracts and control for all treatments. For gall index, in 2017 and 2018, Control recorded 4.27 and 4.47 whereas Ageratum conyzoides followed with 2.72 and 2.66, Piliostigma thonningii (2.56 and 2.65), Triumfetta rhomboidea (2.44 and 2.51) and Newbouldia laevis was least with 2.22 and 2.28 respectively. For final nematode population, control plot (CT) had significantly (P=0.05) higher number with a mean of 890.6 nematodes followed by A. conyzoides (215.4), T. rhomboids (204.6), P. thonningii (200.6) and least was N. laevis with 188.9 nematodes. Control plants had significantly heavier mean root weight (307.7 g) than A. conyzoides (222.0 g), P. thonningii (170.8 g), N. laevis (169.5 g) and T. rhomboidea (166.7 g). The research indicates that the four plant leaf extracts are at par in their ability to prevent/reduce damage by M. javanica on eggplant and therefore can be used as environmentally friendly tool for controlling the nematode.