Use of botanicals and poultry manure as potential bio-nematicides against root-knot nematodes infecting cucumber

Abstract

Crop losses due to root-knot nematodes are typically mitigated by the application of highly toxic chemical nematicides. Which can be expensive. Consequently, ongoing efforts are focused on the search for ecofriendly and sustainable strategies. The purpose of this study was to assess the efficacy of soil amendments in management of Meloidogyne incognita both a screen house and a field setting. Four varieties of cucumber, all infected were evaluated for the effectiveness of soil amendments against in nematodes. The experimental design included a factorial set-up in a completely randomised design and for the screen house and a randomized complete block design for the field. Phytochemical screenings of botanicals were carried out using Gas Chromatography Mass Spectrometry. Data were collected on various parameters, including fresh root weight, fresh shoot weight, fruit yield, soil and root nematode population, reproduction factor, number of egg mass, and gall index. Numerical data obtained were analyzed using descriptive statistics of Microsoft excel packaged and analysis of variance (ANOVA). In the screen house, all four susceptible cucumber varieties exhibited highly pathogenicity when exposed to 2000 juveniles of root-knot nematodes. Powdered poultry manure demonstrated comparable efficacy to carbofuran in reducing the number of root-knot nematodes in the root of cucumber and soil, as well as the number of egg mass, root galling and reproduction factor within the screen house. Cucumber treated with carbofuran (C1cb) and powdered poultry manure (C1pd) showed reduction of 0.01 and 0.001 respectively. Notably, cucumber treated with powdered poultry manure recorded gall index of 24.50 (C1pd), while untreated cucumbers had a gall index of 5.25 (C4c). Phytochemical screening revealed the presence of Xanthane, Imidazole and Boron etc. The extract of powdered poultry manure significantly (P<0.05) inhibited egg hatching, increased juvenile mortality, and enhanced yield cucumber compared to other treatments. Phytochemicals such as Xanthane, Imidazole and Boron in botanicals likely contributed to the observed effects in the results.