A Multi‐Tactic Approach to Manage Weed Population Dynamics in Crop Rotations

Abstract

L.) are now grown with winter wheat and fallow. Integrating crop diversity with other cultural tactics enabled No-till systems have enabled producers to change crop rotations in producers to effectively control weeds with 50% less the semiarid Central Great Plains. Previously, winter wheat (Triticum aestivum L.)-fallow was the prevalent rotation; now producers grow herbicide inputs compared with their initial experiences warm-season crops along with winter wheat and fallow. Initially, weed with no-till rotations (Anderson, 2003). The cultural management was difficult in no-till rotations. However, an ecological approach reduced weed community density in their fields, approach to weed management, which integrates knowledge of weed thus minimizing the need for herbicides to control weeds. population dynamics with cultural tactics and long-term planning, has Pedigo (1995) suggested that scientists develop conenabled producers to control weeds with 50% less herbicides. This ceptual models to guide development of multi-tactic article explains the cultural tactics and ecological reasoning that led programs. In this article, we explain the cultural tactics to this successful approach; our goal is to provide insight and ideas and ecological reasoning that led to this approach with for other scientists and producers to plan multi-tactic weed manageweed management in the Central Great Plains; this exment. The ecological approach emphasizes three goals related to weed ample may provide insight and ideas for producers and population dynamics: enhancing natural loss of weed seeds in soil, reducing weed seedling establishment, and minimizing seed produc-

Impacts of Organic Zero Tillage Systems on Crops, Weeds, and Soil Quality

“…Diverse crop rotations indirectly impact weed population through tillage effects, because tillage timing and frequency varies with crop species [59,61]. Weed species that are phenologically synchronous with a particular crop species tend to survive and proliferate with that crop [72]. Smith [61] concluded from a three-year study that spring tillage produced weed communities dominated by early emerging spring annual forbs and C4 grasses, whereas fall tillage favored later emerging annuals and C3 grasses.…”

“…Smith [61] concluded from a three-year study that spring tillage produced weed communities dominated by early emerging spring annual forbs and C4 grasses, whereas fall tillage favored later emerging annuals and C3 grasses. Planting crops with differing phenologies, such as winter wheat vs. maize, helps to disrupt crop-weed life cycle synchronies [10], although Anderson [72] reported that alternating two years of a warm season crop with two years of a cool season crop reduced weeds more than alternating cool and warm season crops on a yearly basis in ZT systems managed conventionally. Crop rotation effects also vary with tillage system.…”

Biotic interactions, ecological knowledge and agriculture

“…In one case, a combination of crop rotation, crop sequence, no-till, residue management and competitive crop canopies has enabled wheat growers in the Central Great Plains of the USA to reduce pesticide use by 50% (Anderson 2005). In this work, researchers used an empirical life cycle simulation based on demographic knowledge of major weed species to identify the best rotations and crop sequences for reducing weed growth and seed production (Anderson 2004).…”

“…This requires a greater emphasis on researcher/farmer partnerships to conduct fieldbased adaptive research and a greater investment in monitoring system performance as adaptations are made. Others have also recognized their need for innovative interdisciplinary partnerships and a shift from a research-extension-diffusion model to an interactive social learning process that incorporates both farmer and researcher knowledge (Barberi 2002;Roling et al 2004;Anderson 2005;Cherr et al 2006;Hobbs & Hilborn 2006;Warner 2006). Participatory research integrated with farmer education has more than 20 years of history in agricultural development, with some notable success such as IPM use in Asian rice systems (Matteson 2000).…”

Sustainable Weed Management for Conservation Agriculture: Options for Smallholder Farmers

“…For example, cutleaf evening primrose (Oenothera laciniate Hill) has become resistant to glyphosate and paraquat [33,40,41]. Therefore, alternatives to herbicides should be promoted to support adoption of CA in a farming environment where resistance to herbicides has occurred.…”