Effect of chemical and alternative weed management on weed composition in banana greenhouses with full and deficit irrigation levels

Background:   In banana greenhouses in Türkiye, extensive herbicide use and high irrigation demand create environmental and management challenges. However, the effects of herbicide application frequency and irrigation on weed control strategies and their effectiveness remain unclear.

Objective:   The research, conducted in Mersin in 2022–2024, evaluated the effects of alternative weed control methods (mowing and geotextile mulching) and sequential herbicide treatment programs (oxyfluorfen, pendimethalin, indaziflam, glyphosate, diquat) under full (100%) and deficit (50%) irrigation.

Methods:   The experiment was established using split-plot design, with irrigation levels assigned to the main plots and randomized subplots arranged in three replications. Control for coverage (% population thresholds), weed density (plant m^-2), and end-of-experiment dry biomass (g m^-2) were measured.

Results:   Weed community changes were evaluated using Shannon-Wiener and Simpson indices, and treatment–species relationships were analyzed by canonical discriminant analysis (CDA). Herbicide treatments (especially indaziflam+diquat; 1.00 plant m^-2; 7.92 g m^-2) reduced weed populations compared to the weedy control. Mulching (0.00 plant m^-2; 0.00 g m^-2) was the most effective. Mowing demonstrated partial effectiveness, achieving only limited weed suppression (41.09 plant m^-2; 125.00 g m^-2). Irrigation levels did not significantly affect weed density or biomass, whereas control methods significantly altered weed composition, species abundance, and diversity. Setaria viridis decreased depending on treatments, while Cardamine occulta, Oxalis spp., Urtica urens, and Amaranthus viridis increased. CDA revealed that weed treatments significantly influenced species composition.

Conclusions:   Integrating alternative and chemical control programs, and minimizing chemical use, are vital for sustainable banana production and for maintaining ecological balance.

Keywords:
Community; Modified Control Programs; Mulching; Suitable Herbicides; Sustainability