New Weed Control Options for Leeks

 

 

Leeks are in the onion family and are increasingly important crop in Monterey County. In 2017, there were 475 acres produced worth $8.6 million. They are mostly established by transplanting and days to maturity is generally 120+ days, but varies widely depending on the time of year and market demand. Given the long crop cycle and the lack of a dense crop canopy, leeks are susceptible to successive waves of weed emergence. Growers complain that leeks “blow up” weed populations by allowing a significant number of weeds to mature and set seeds.

 

The preemergent herbicides DCPA and pendimethalin are registered for use and provide good weed control. However, post emergent herbicides such as bromoxynil and oxyfluorfen which provide excellent control of escaped weeds in onion production are not registered on leeks. In Canada prometryn is registered for use on leeks. In 2016, we began studying this material for use on leeks to bringing it into the US market. This project is now supported by the IR4 program and they are evaluating crop safety and developing a tolerance to eventually bring it to market.

 

 

Prometryn is particularly useful because it controls emerged weeds and has preemergent activity as well, which fills a need for this long-season crop. Table 1 shows weed counts and phytotoxicity ratings for a trial established on August 25, 2017. On the September 20 evaluation date, there was slight phytotoxicity in the prometryn treatments on the leeks, but no difference between the two application timings. Phytotoxicity consisted of a bending down of older leaves (Photo 3). The plants appeared to have recovered for the most part from this issue by the October 10 and November 9 evaluation dates, but bent leaves could still be observed to a small degree. Bromoxynil caused burning on the tips of the leaves that was evident on all evaluation dates. All rates and timings of prometryn eliminated weeds in the plots (Photos 1 & 2). There was no statistical difference in yield, but there is a trend that higher rates of prometryn had lower tonnage than the untreated control.

 

The potential for prometryn as a preemergent herbicide for use on leeks is quite exciting. It has the potential to provide a level of weed control in this crop that we have not seen. We are exploring its use on other allium crops as well and recently observed good safety on onions in one trial when it was applied at the 5th true leaf stage.

 

 

 

 

Video: When is Sustainable Packaging Coming in the Canadian Agri Food Industry? 3 Critical Perspectives

Canada’s regulatory landscape on single-use plastics is complex but a recent ruling by the Federal Court of Appeal sided with the government’s intent to eliminate single-use plastics. What does this mean for the Canadian agri-food industry? How can companies find the right balance between regulatory compliance and implementing costly alternative solutions? What are retailers and consumers saying about sustainable packaging? This webinar features Joshua Goodman, Head of Corporate Sustainability, Sobeys; Marie-Anne Champoux-Guimond, Director of Sustainability, Keurig Dr Pepper Canada and Glenford Jameson, Canadian Food Lawyer, G.S. Jameson and Company

This 60-minute webinar brings together three industry leaders to examine the opportunities, challenges, and realities of the path forward. In this session, you will gain insights into:

•Canada’s regulatory roadmap and timeline on eliminating single-use plastics

•Current end-of-life solutions for plastics and alternative packaging solutions

•The need to have a corporate strategy that aligns with reality at the retail shelves

•How major brands and retailers are pivoting

•Supply chain considerations

•Common misconceptions