European Journal of Sustainable Agroecosystems

Background: Root-knot nematodes (Meloidogyne spp.) are among the most menacing parasites of soil that result in much loss of yield in cucumber (Cucumis sativus L.) agriculture. Chemical nematicides have gained attention recently, because of the environmental impact and urgent need for durable agricultural production systems. The combination of arbuscular mycorrhizal fungi (AMF) and organic supplements has proven to be an interesting way to enhance plants’ protection, maintain soil’s health, and control nematodes.
Objective: The objective of this study was to determine the effectiveness of the incorporated application of AMF and organic amendments in the control of root-knot nematodes and the improvement of soil biological characteristics, plant physiological performance, and cucumber yield under greenhouse conditions.
Methods: At the experimental farm of the Institute of Agricultural Sciences, Delhi University, a factorial randomised block design was implemented and replicated four times in the two consecutive seasons from 2022 to 2024. The five treatments that were trialled were: (i) uninoculated control; (ii) AMF treated; (iii) organic amendments (vermicompost + neem cake) treated; (iv) AMF + organic amendments treated; (v) carbofuran as a chemical nematicide standard. Nematode infestation, AMF root colonization, soil microbial biomass carbon, soil enzyme activities (dehydrogenase, phosphatase and urease), plant physiological traits, nutrient uptake, antioxidant enzyme activities, defense compounds and fruit yield data were collected.
Results: The combined method of AMF + organic amendment treatment produced the best results in nematode suppression since it achieved a decrease in root gall formation by 87.3%, its ability to produce the egg mass was reduced by 92.1%, and juvenile second-stage population by 89.6% compared to the untreated control. The AMF colonization was 72.4%, while microbial biomass carbon in the soil increased by 41.2%. The increase in the activity of the soil enzymes was in the range of 38-52% (dehydrogenase, phosphatase, and urease), which suggests that the biological functioning of the soil is improved. With regard to the treated plants, they showed better chlorophyll and relative water content, more activity of antioxidant enzymes, and more accumulation of compounds related to the protective properties. The fruit yield increased to 44.3 t ha⁻¹ in comparison to 18.7 t ha⁻¹ in the untreated control.
Conclusion: Combining mycorrhizal fungi and organic amendments effectively controlled rootknot nematodes while enhancing soil biological activity, plant defense mechanisms, nutrient uptake, and cucumber yield. This environmentally friendly approach presents an alternative to synthetic nematicides and facilitates sustainable nematode management for intensive cucumber production.