Sustainable Control of Meloidogyne incognita and Enhanced Tomato Growth by Botanical Extracts under Greenhouse Systems

A pot trial was conducted to assess the impact of aqueous and ethanolic extracts of four plant species: Chili pepper, Dill, Garlic, and Peppermint applied either alone or at half dose combined with half dose of oxamyl on Meloidogyne incognita infecting tomato plants. Data indicated that all aqueous and ethanolic extracts improved plant growth parameters and reduced nematode indices. The application of the ethanolic garlic extract alone showed the greatest reduction of second-stage juveniles (97.8%), galls (94.3%), and egg masses per root system (96.2%). It also showed 86.7% increase in plant height, 97.7% increase in total plant fresh weight, 130% increase in shoot dry weight, and 37.1% increase in the number of leaves per plant in this study. The application of the aqueous garlic extract ranked the second in this regard, while the plants receiving the aqueous dill extract showed the lowest quantitative values ​​in improving plant growth parameters, especially in nematode-infected plants. In binary treatments at half dose of the extract and pesticide, the garlic ethanolic extract treatment also showed the highest reduction percentages of 100, 99.6, and 100% for the number of second-stage juveniles/pot, galls, and egg masses. All tested components showed remarkable increase in total chlorophyll, polyphenol, and flavonoid contents in leaves of tomato exceeding those of nematode alone.