Nematicidal Efficacy of Carissa carandas Extracts against Meloidogyne incognita

Plant-parasitic nematodes (PPNs), especially root-knot nematodes (RKNs) of the genus Meloidogyne, significantly diminish the productivity of horticultural crops, leading to global yield losses valued at approximately $157 billion. Traditional chemical treatments for PPNs pose environmental hazards, prompting the need for eco-friendly alternatives. This study explores the nematicidal potential of Carissa carandas L. (Karonda) plant extracts against Meloidogyne incognita. Various parts of C. carandas were collected, processed and extracted using solvents such as methanol, ethanol, ethyl acetate, chloroform and water. The efficacy of these extracts was tested on egg-hatching inhibition and juvenile mortality of M. incognita. Methanol extracts, particularly from seeds, demonstrated the highest nematicidal activity, with significant juvenile mortality and egg-hatching inhibition of M. incognita. Results indicated that the nematicidal properties are likely due to phytochemicals such as alkaloids, flavonoids and organic acids present in the extracts. This study suggests that C. carandas extracts, especially methanolic seed extracts, are promising eco-friendly alternatives for managing RKNs and promoting sustainable agricultural practices. Further research is recommended to isolate and to identify the active compounds responsible for the nematicidal activity.