Understanding the effects of crop management practices on weed survival and seed production is imperative in improving long-term weed management strategies, especially for herbicide-resistant weed populations. Kochia [Bassia scoparia (L.) A.J. Scott] is an economically important weed in western North American cropping systems for many reasons, including prolific seed production and evolved resistance to numerous herbicide sites of action. Field studies were conducted in 2014 in a total of four field sites in Wyoming, Montana, and Nebraska to quantify the impact of different crop canopies and herbicide applications on B. scoparia density and seed production. Crops used in this study were spring wheat (Triticum aestivum L.), dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), and corn (Zea mays L.). Herbicide treatments included either acetolactate synthase (ALS) inhibitors effective on non-resistant B. scoparia or a non–ALS inhibiting herbicide effective for both ALS-resistant and ALS-susceptible B. scoparia. Bassia scoparia density midseason was affected more by herbicide choice than by crop canopy, whereas B. scoparia seed production per plant was affected more by crop canopy compared with herbicide treatment. Our results suggest that crop canopy and herbicide treatments were both influential on B. scoparia seed production per unit area, which is likely a key indicator of long-term management success for this annual weed species. The lowest germinable seed production per unit area was observed in spring wheat treated with non–ALS inhibiting herbicides, and the greatest germinable seed production was observed in sugar beet treated with ALS-inhibiting herbicides. The combined effects of crop canopy and herbicide treatment can minimize B. scoparia establishment and seed production.

I n recent years, California's agriculture industry has been hindered by a declining supply of farm labor (Taylor et al. 2012), generating interest among growers in methods to reduce labor requirements for thinning, weeding, irrigating and harvesting (Fennimore et al. 2010; 2014). Thinning lettuce is particularly labor intensive, and most lettuce fields in California are hand-thinned (manually thinned). Automated lettuce thinners that use machine vision and computer image processing, and a spray system to remove unwanted plants, were introduced to the Salinas Valley 4 years ago. Growers are evaluating their cost and performance to see if they have a fit in their operations. An automated thinner, which typically needs only one person to run it, removes plants to ensure accurate final plant spacing and provide a measure of weed control (Chu et al. 2016). Machine vision technology

Herbicide resistance has been studied extensively in agronomic crops across North America but is rarely examined in vegetables. It is widely assumed that the limited number of registered herbicides combined with the adoption of diverse weed management strategies in most vegetable crops effectively inhibits the development of resistance. It is difficult to determine if resistance is truly less common in vegetable crops or if the lack of reported cases is due to the lack of resources focused on detection. This review highlights incidences of resistance that are thought to have arisen within vegetable crops. It also includes situations where herbicide-resistant weeds were likely selected for within agronomic crops but became a problem when vegetables were grown in sequence or in adjacent fields. Occurrence of herbicide resistance can have severe consequences for vegetable growers, and resistance management plans should be adopted to limit selection pressure. This review also highlights resistance management techniques that should slow the development and spread of herbicide resistance in vegetable crops.

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Cover cropping has been strongly promoted, but few growers have realized the benefits of this practice due to challenges linked to economic returns and whole-system management. In the western United States, winter legumes including faba bean have the potential to add economic value while offering soil health benefits compared with fallow fields. This experiment assessed the potential of five vegetable faba bean varieties for fresh pod yield, fresh pod quality, and biomass N return under a single and multiple pod harvest scheme. Vegetable faba bean varieties were further compared with two popular cover crop faba bean varieties, ‘Bell bean’ and ‘Sweet Lorane’ for cover crop and biomass N return benefits. The experiment revealed significant (P ≤ 0.05) genotypic variation for vegetable fresh pod yield, dry biomass, fresh pod quality, pod N removal, biomass N return, and C:N in three testing environments under the single and multiple harvest schemes. Finally, the vegetable variety ‘Vroma’ produced high average fresh pod yield under the single (16,178 kg·ha−1) and multiple (38,928 kg·ha−1) harvest schemes while maintaining high biomass N return under the single (119 kg·ha−1 N) and multiple harvests (97 kg·ha−1 N) compared with the cover crop varieties (128 kg·ha−1 N). This experiment demonstrated that a single fresh pod harvest on an early and high yielding faba bean variety can generate economic returns while also providing cover crop benefits that are comparable to termination of a faba bean cover crop on the same date.