Efficacy of Some Botanical Extracts on Root-Knot Nematode (Meloidogyne incognita) Egg- Hatch and Juvenile Mortality in vitro

Abstract

The study was conducted at the Department of Crop and Environmental Protection Laboratory University of Agriculture Makurdi to compare the nematicidal activity of 3 different plant leaf and seed extracts from Ricinus communis, Jatropha curcas and Moringa oleifera Lam on egg-hatch inhibition and juvenile mortality in vitro. The experiment was laid out in Completely Randomised Design (CBD) with a 3x7x3 factorial arrangement replicated three times. Aqueous extracts from leaves and seeds of Moringa oleifera, Jatropha curcas and Ricinus communis (15 g/100ml) were further diluted into 10, 20 and 30% V/V respectively. A 10ml aliquot of aqueous extract dilutions (10, 20 and 30%V/V) was introduced into Petri dishes containing 50 and 100 fresh egg- masses and juveniles of M. incognita, respectively. Egg masses and second stage juveniles were exposed to the concentrations of the aqueous leaf and seed extracts for 24, 48 and 72hrs.  The results show that there was a significant difference (P<0.05) between the various exposure time on eggs-hatch inhibition and juvenile mortality. The Highest number of eggs-hatch inhibition and juvenile mortality were recorded at 72 >48>24 hours. There was also a significant difference (P<0.05) between the different concentrations used on percentage egg-hatch inhibition and juvenile mortality. 10% v/v concentration recorded the least percentage mortality while 30% v/v concentration recorded higher egg-hatch inhibition and juvenile mortality. There was no significant difference (P>0.05) between the different leaf and seed extracts as all botanicals had an effect on egg-hatch and juvenile mortality. However, all untreated control recorded (0%) egg-hatch inhibition and juvenile mortality. The study showed that leaf and seed extracts of Moringa oleifera, Jatropha curcas and Ricinus communis, decreased egg hatch and increased juvenile mortality.  The study also revealed that egg hatch and juvenile mortality were dependent on the time of exposure and concentration of the extracts.