Accomplice substantially increases weed control with low and high liberty use rates
Liberty @ 22 fl oz/A + Accomplice @ 0.5%
- Improves Liberty performance by 51%, increasing weed control from 46% to 70%
Liberty @ 43 fl oz/A + Accomplice @ 0.5%
- Improves Liberty performance by 50%, increasing weed control from 61% to 92%
"“We observed real world benefit with the addition of Attune products to improve the effectiveness of Liberty herbicide.”
COO, VP, and Research Director
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The U.S. grew 89.6 million acres of soybeans, 81.8 million acres of corn, and 13.5 million acres of cotton in 2018. More than 90% of this combined acreage is genetically modified (GMO) to be resistant to specific herbicides. When herbicide tolerant GMO crops were first introduced, they were only tolerant to glyphosate, the active ingredient in Monsanto’s Roundup. Several years later, Bayer introduced new GMO crop varieties that were tolerant to glufosinate, the active ingredient in Liberty. Recently, two more herbicides were added to herbicide tolerant GMO crop varieties, 2,4-D and dicamba, bringing the total number of herbicides which can be sprayed on herbicide tolerant GMO crops to four.
The primary reason additional herbicides have been added to herbicide tolerant GMO crops is that 38 weed species have resistance to glyphosate. These four herbicides use different modes of action to control weeds. This allows growers to alternate herbicides based on their mode of action or combine two or more herbicides with different modes of action as a means of dealing with herbicide resistant weeds. As a result, seed companies are offering herbicide tolerant GMO crop varieties today that are tolerant to multiple herbicides, such as tolerance to glyphosate + glufosinate, glyphosate + dicamba, or glyphosate + glufosinate + 2,4-D. The bottom line is that it will be critical to maintain the effectiveness of these four herbicides in order to preserve future weed control on these broad acreage crops.
Liberty glufosinate is becoming more important in terms of its role in herbicide resistance management for two reasons. First, herbicides are often divided by the types of weeds they control, most often into two groups, broadleaf weeds and grasses. Roundup and Liberty control both broadleaf weeds and grasses, and are often referred to as total vegetation herbicides. Dicamba and 2,4-D, on the other hand, only control broadleaf weeds. Second, as previously noted, there are several important weed species that are resistant to glyphosate. Both dicamba and 2,4-D have been in use for well over 40 years and there are weeds that are resistant to both of these herbicides. Glufosinate has by far the fewest number of resistant weed species reported.
While glufosinate use in GMO crops has been increasing, it has not performed consistently in arid (dry) areas. The reason for the inconsistent performance was identified by researchers at the University of California-Davis who reported that weed control with glufosinate was greatly impacted by relative humidity. With a relative humidity of 90% before and after application, glufosinate provided high levels of weed control while at a relative humidity of 35%, substantially lower weed control was observed.
Attune Agriculture believed that the reason glufosinate performance is impacted by relative humidity is because glufosinate needs a liquid interface between the spray droplet and leaf surface in order to be absorbed by the plant. Under high humidity conditions, glufosinate spray drops have more time to be absorbed than under low humidity conditions when glufosinate spray drops evaporate more quickly. Attune believes that our adjuvant technology, which increases the amount of spray that reaches the plant and slows down droplet evaporation, would improve glufosinate performance.
To test this concept, Attune engaged RD4Ag to conduct a test under the arid conditions of Yuma, AZ evaluating the impact of Attune’s adjuvant Accomplice on the performance of Liberty glufosinate. Liberty was applied at 22 fl oz/A which is a typical use rate and 43 fl oz/A which is a burndown rate, either alone or tank mixed with Accomplice at either 0.25% (1 quart/100 gallons spray) or 0.5% (2 quarts/100 gallons spray). Treatments were made to weeds growing in a fallow field, some of which were as much as 4 feet tall. Accomplice at 0.5% improved weed control with the low rate of Liberty by 51.2% and with the high rate of Liberty by 49.6%.