Roundup Ready (RR) alfalfa was the fifth glyphosate-tolerant crop to be commercialized in the United States following canola, soybeans, cotton and corn (1996, 1997, 1997, and 1998, respectively). Its release has been more contentious and highly disputed than any of its predecessors. Its introduction in the fall of 2005 was short lived and an injunction was issued by a circuit court judge in March of 2007 halting new plantings but allowing production on existing fields to continue. Roundup Ready alfalfa was deregulated for the second time in February of 2011 after a 4-year ban. Earlier this month a U.S. federal judge upheld this decision.
Growers and the alfalfa industry as a whole now have a full production cycle of experience with the initial plantings and a season or partial season’s worth of experience with the new plantings that have occurred in 2011. University of California researchers Dan Putnam and Steve Orloff conducted a survey of alfalfa growers to better understand alfalfa hay-grower attitudes and perceptions regarding RR alfalfa. The full survey responses and background information can be found at: http://alfalfa.ucdavis.edu/+symposium/proceedings/2011/11-332.pdf
Of the 381 people who completed the survey, 113 of them have grown RR alfalfa. The results indicated that a large majority of them (90%) were either satisfied, very pleased, or that the technology far exceeded expectations. Eight responded that they were disappointed, and two extremely disappointed. A majority (71%) said that they would plant it again, 20% said maybe, and 9% said no. Better weed control, simplicity, and flexibility of weed management were the key advantages cited by respondents, with control of problematic weeds a key point for many. Cost of seed was cited by 80% of all respondents as the major negative. This response was more than four times more popular than any of the other choices which included weed control was not effective, Roundup resistant weeds, don’t like the technology use agreement, and varieties don’t seem to yield well. The least popular response was difficulties in marketing RR alfalfa, indicating that this has not been a significant problem for those who have grown RR alfalfa.
It appears that growers are becoming convinced of the risks of herbicide-resistant weeds. Forty-one percent of respondents indicated a concern for Roundup-resistant weeds as a consequence of the use of the technology, while only 25% indicated that it is not a concern. The rest indicated that they were not sure but that maybe resistant weeds are a concern.
Twenty-seven percent of growers reported that RRA varieties yielded more than conventional varieties, 12% felt that they yielded less, and about 51% indicated that yields were equal to conventional varieties. UC field research data has indicated few differences between RR alfalfa varieties and conventional varieties as a group, with greater differences within either conventional or RR variety groups.
Most RR alfalfa growers (approximately 52 percent) who responded to the survey believed that the forage quality of RR and conventional varieties was about the same. However, 38 percent of the growers felt that RR varieties were higher in quality than conventional varieties compared with less than 3% percent of growers who felt RR varieties were lower quality. Limited research conducted by UC showed that in the absence of weeds, there was no difference in forage quality on average between RR varieties and conventional varieties. While we did not see a difference in forage quality between varieties, there could be a difference in commercial fields if the RR field had superior weed control.
The RR alfalfa system greatly simplifies weed management in alfalfa. Depending on the grower’s philosophy toward GE crops, their market, and the weed pressure encountered, the RR system has been shown to have significant benefits for many producers. It has proved to offer some important environmental benefits for those areas where traditional herbicides are problematic.
Effective control of most weeds in alfalfa is often feasible with conventional herbicides; they just require a higher level of weed science expertise—ability to properly identify weeds, use more precise application timing, and have the knowledge to select the proper herbicide, rate, or herbicide tank mixes to control the weeds encountered in a field. The advantages and cost effectiveness of RR alfalfa are not so great as to preclude a grower who chooses to produce conventional alfalfa from competing effectively with RR alfalfa growers. Which approach makes the most sense for a grower comes down to a personal decision, specific weed pressure and species, economic analysis, and the sensitivity of markets.
For a more complete discussion of the survey results and what we have learned about RR alfalfa to date see the full article at: http://alfalfa.ucdavis.edu/+symposium/proceedings/2011/11-184.pdf
This topic was presented at the Western Alfalfa Conference in Las Vegas in December. The conference also addressed the issue of coexistence of RR and conventional alfalfa. The complete proceedings from this meeting are available at: http://alfalfa.ucdavis.edu/+symposium/proceedings/search.aspx
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