Evaluation of the White and Red Cabbage Efficiency as Pre-Plants in the Control of Johnsongrass in Tomato Cultivation

Abstract

The experiments were conducted in tomato fields and greenhouses in 2019 and 2020 to evaluate the allelopathic effects of white and red cabbage with and without mulch to control johnsongrass. The effect of these methods on Johnsongrass life cycle durations, density, length, fresh and dry weight of stems, and rhizomes were determined. Also, the effect of the treatments on the quantity and quality of tomato production was evaluated. In the greenhouse experiment, tomato seedlings were planted with johnsongrass seeds and rhizomes and were treated with plants' aqueous extracts at concentrations of 2, 5, and 10%. The germination and dry weight reduction percentage of johnsongrass were calculated. Isothiocyanates contained in white and red cabbage were identified by GC-MS. White and red cabbage with mulch reduced johnsongrass density by 69.1 and 65.9%, while the dry weight of stems and rhizomes were reduced by 78.2-74.2% and 71.3-68.0%, respectively. White and red cabbage with mulch treatments achieved an increase in tomato production by 632.1 and 621.8%. According to GC-MS analysis, the predominant isothiocyanate in white cabbage was 3-(methylsulfinyl) propyl (23.43%) and 4-(methylsulfonyl)butyl (10.79%) in red cabbage. The results of these experiments confirm that both white and red cabbage have allelopathic potential that can be used in weed control.