Weed Diversity and Community Composition in Organic Tomato Fields as Influenced by Mulching and Hand Weeding Frequency

Abstract

Weed infestation is one of the major challenges in organic tomato production systems, where the limited use of synthetic herbicides necessitates reliance on cultural and mechanical weed management practices. Mulching and hand weeding are widely adopted approaches for suppressing weed growth and improving crop productivity; however, their effects on weed diversity and community composition require further investigation. The present study was conducted to evaluate the influence of different mulching treatments and hand weeding frequencies on weed diversity, abundance, and community structure in organic tomato fields. Field experiments were carried out using various organic mulch materials combined with different hand weeding intervals under organic cultivation conditions. Weed species composition, density, biomass, and diversity indices were recorded throughout the cropping season, along with observations on tomato growth and field weed suppression efficiency. The results demonstrated significant variation in weed community composition among different management treatments. Mulching treatments effectively reduced weed emergence and biomass by limiting light penetration and modifying soil microenvironmental conditions. Organic mulches combined with frequent hand weeding resulted in the lowest weed density and greatest suppression of dominant weed species. In contrast, untreated plots exhibited higher weed diversity and greater abundance of aggressive annual and perennial weeds. Differences in weed flora composition were observed depending on mulch type and weeding frequency, indicating that management practices strongly influenced weed community dynamics. Improved weed suppression also contributed to better tomato growth and reduced crop–weed competition. The findings highlight the importance of integrating mulching and timely hand weeding as sustainable weed management strategies in organic tomato production systems.