Protecting a promising crop: herbicide tolerance in sweet lupin
Lupin (Lupin albus) is a valuable multipurpose legume crop with emerging production opportunities in North Dakota. Its high protein, high fiber, and low-fat content make it a valuable crop for both human and animal consumption, and its benefits to soil health, like nitrogen fixation and improved soil structure, make it a valuable crop rotation option. However, a major challenge in any emerging crop is the difficulty of weed control.
In the herbicide labeling world, lupins are frequently considered a dry edible bean. In trials at the CREC, we have found that some broadly registered herbicides can and do cause significant crop injury on lupin. Producers need to know which herbicides cause crop injury and the extent of the crop injury to make production decisions. To update this area of lupin production practices, a demonstration was conducted at the CREC in which ten different treatments were tested on white lupin (Table 1).
The demonstration was setup as a 10-foot-wide by 100-foot-long strip with each treatment applied across the strip. Reflex and Brawl II are currently labeled for post-emergence use on lupin. Zaltus SC and Pursuit are labeled only for pre-emergence use. The rest of the products are not currently labeled for use on lupin. After herbicide application, each treatment strip was evaluated at 7 and 14 days after application.
Preliminary results from this demonstration showed a range of plant damage from 2% to 80% (Chart 1). Of the post-emergence treatments currently labeled for lupin, Brawl II caused low plant damage, while Reflex caused high plant damage. Of the herbicides labeled for pre-emergence, Zaltus SC had high plant damage but Pursuit had low crop damage. Neither Outlook nor Tough are labeled for lupin use but would add additional tools for weed control in lupin.
The results from this demonstration provide critical guidance for producers making production decisions for the upcoming season. As we look ahead, the next step is to test additional rates and conditions to not only confirm these preliminary results but also begin the process for additional herbicide labeling, which could include promising molecules like diflufenican. An herbicide that is currently being use as post-emergence with proven effectiveness in lupin cultivation in Australia and South America. By continuing our research, we hope to establish a comprehensive guide for lupin production in the coming years.
Agustin San Pedro
Agustin.SanPedro@ndsu.edu
Agronomy Research Specialist
