Alan Leslie, University of Maryland
Guihua Chen, University of Maryland
Cerruti R. Hooks, University of Maryland
Weeds are a persistent problem in organic vegetable production systems. Conventional vegetable farmers benefit from the availability of low-cost, synthetic herbicides that can be used as pre-emergent and/or rescue treatments to help manage a wide range of weeds. However, organic vegetable farmers must rely on several non-chemical tools to obtain adequate weed suppression. Hand-weeding and cultivation/tillage are commonly used by organic farmers to manage weeds, but these tools can add significantly to production costs. In addition, frequent tillage can reduce soil health and quality and cause additional weed flushes. Organic vegetable farmers can benefit significantly from the application of multiple tactics concomitantly to suppress weeds. Integrated weed management (IWM) involves the use of chemical, cultural, genetic, biological, and mechanical practices in complementary ways to effectively reduce weed pressure. The aim of IWM is to limit the reliance on any one weed management tool. Generally, weeds are highly adaptive and can often find ways to escape control by any single weed control method. As such, an integrated approach that focuses on making cropping systems less favorable to weed establishment and proliferation through the use of multiple management practices is needed.
Individual weed management tools vary in scale from farm-wide to within field tactics. At the whole-farm scale, farmers can adopt practices such as not planting vegetables in fields with history of severe weed infestations, practicing good sanitation to reduce weed seed spread, and rotating crops that demand different weed suppression practices—subsequently making it difficult for individual weeds to adapt to changing field environments. At the field scale, selecting competitive crop cultivars, increasing crop diversity, and mulching are among the strategies that can allow crops to better compete with weeds. By combining these and other strategies, farmers can produce vegetables in ways that disrupt the life cycles of weeds. In their article, Managing weeds in vegetables organically, Drs. Hooks, Leslie, and Chen describe a wide range of weed management strategies that can be considered for adoption into an IWM program. The article provides findings from recent research aimed at the development of sustainable and organically compatible weed management practices. To read the full article and learn more about managing weeds in organic vegetables, visit the Organic Vegetable Production section of the University of Maryland Extension website, or use the following URL: https://extension.umd.edu/sites/default/files/_images/programs/mdvegetables/OrganicWeedMgntVeg21May2016(1).pdf