Elucidating the potential of fly ash in root-knot nematode (Meloidogyne incognita) suppression on okra (Abelmoschus es-culentus L.): insights into cellular viability and host defence system

Authors: BHAT, ADIL - Aligarh Muslim University; SHAKEEL, ADNAN - Aligarh Muslim University; WAQAR, SONIA - Aligarh Muslim University; Handoo, Zafar; KHAN, ABRAR - Aligarh Muslim University

Submitted to: Physiological and Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2023
Publication Date: 7/1/2023
Citation: Bhat, A.A., Shakeel, A., Waqar, S., Handoo, Z.A., Khan, A.A. 2023. Elucidating the potential of fly ash in root-knot nematode (Meloidogyne incognita) suppression on okra (Abelmoschus es-culentus L.): insights into cellular viability and host defence system. Physiological and Molecular Plant Pathology. 126(1):Article 102042. https://doi.org/10.1016/j.pmpp.2023.102042.
DOI: https://doi.org/10.1016/j.pmpp.2023.102042

Interpretive Summary: Plant-parasitic nematodes are microscopic worms that feed on plants and cause an estimated ten billion dollars of crop losses each year in the United States and 100 billion dollars globally. Various approaches have been used for their control, among which include chemicals, host plant resistance, crop rotation, soil solarisation, and introduction of antagonistic organisms. Crop rotation is very commonly used for nematode control, but it requires adequate land and these alternate crops must bring profits to the grower. Various grades of fly ash were applied in pots containing autoclaved soil before seed sowing. Results indicated that the application of 20% FA level (80:20 w/w field soil:fly ash) was found most beneficial for soil health, improving growth and yield traits, physio-bio-chemical attributes, and antioxidant properties of okra by alleviating the harmful effects of root-knot nematode (Meloidogyne incognita) compared to other treatments. This information will be used by scientists, diagnosticians, growers, action agencies, and extension agencies involved in nematode research and control.

Technical Abstract: In the present era of climatic shift, due to many natural and anthropogenic activities, it is imperative to use eco-friendly products to improve the soil quality and production of food crops, including okra (Abelmoschus esculentus L.). As chemical nematicides are damaging to the environment, there is a need for developing alternate ecofriendly measures for the management of root-knot nematodes (Meloidogyne spp.), which cause major losses to vegetable crops globally. In this regard, a pot experiment was performed under optimal environmental conditions to study the nematicidal properties of fly ash (FA) on okra. Various grades of fly ash were applied in pots containing autoclaved soil before seed sowing. Results indicated that the application of 20% FA level (80:20 w/w field soil:fly ash) was found most beneficial for soil health, improving growth and yield traits, physio-bio-chemical attributes, and antioxidant properties of okra by alleviating the harmful effects of root-knot nematode (Meloidogyne incognita) compared to other treatments. Stomatal attributes of okra were also improved at 20% FA level, as demonstrated by scanning electron microscopy. Galls, egg mass formation and reproduction factor of M. incognita was significantly reduced at 20% FA level. Moreover, laser confocal microscopy combined with scanning electron microscopy revealed that 20% FA application enhanced root cell viability and detoxifies the accumulation of reactive oxygen species.