Investigation on the Efficacy of Leaf Extract of Goat Weed, Ageratum conyzoides on NR Biophysiological Characteristics of Black Gram Vigna mungo Infected with Root–Knot Nematode Meloidogyne incognita

Abstract

Root-knot nematodes, Meloidogyne sp. are economically important plant pathogens affecting root system that can be managed by cultural practices, chemical nematicides and resistant cultivars. Use of nematicides for the management of root knot nematodes are being restricted due to environmental and human health concerns in addition nematicides often do not provide long term suppression of the pathogens. Therefore, there is a need to develop alternate ecofriendly management strategies for the control of root-knot nematodes, including use of biocontrol agents, plant products and organic amendments. Hence, the present study was carried out to evaluate bio-physiological characteristics, such as, NR activity, total chlorophyll and phenol content of nematode infecting black gram Vigna mungo and treated with leaf extract of Ageratum conyzoides.  The study reveals that the NR activity and chlorophyll content were decreased with increasing inoculum levels of Meloidogyne incognita (5 and 10 egg masses) and the phenol content was feared to increase with increasing inoculum levels of Meloidogyne incognita egg masses. In the inoculated plants treated with leaf extract these constituents were found be increasing than the inoculated control plants except the total phenol content.