Ford Baldwin

April 20, 2010

3 Min Read

For so many years Roundup Ready spoiled us all. It made a rice weed scientist out of me because there just was not much demand for a soybean weed guy for about 10 years.

We now face issues with both crops. In soybeans we have better answers to some of the resistance issues — it is a matter of getting them implemented.

In the South, it would appear the available LibertyLink soybean seed has been sold. That technology simply must go forward. There is no question the glyphosate resistance issues will continue to increase as long as we are in glyphosate-only programs.

Marestail and Palmer pigweed have blown up in the South. Because of the corn rotation in the Midwest, that area lags behind the South in resistance development, but they will catch up. The longer they abuse the glyphosate only programs, the quicker they will catch up with us.

Part of the answer lies in more use of different modes of action among the older herbicides. Those programs can help. However, in the good old days when they were all we had, they were very inconsistent.

Soil-applied herbicides are inconsistent partly due to soil moisture reasons. The conventional herbicides were inconsistent due to the very precise timing required.

Also some of these herbicides just were not great on Palmer pigweed, for example, anyway. If you think about it, Roundup Ready soybeans took the market by storm at a time when the varieties were not as good as the better conventional varieties in those days and everyone was mad over new concepts such as technology fees and not being able to save the seed.

Sure the technology was simple and all that, but the big reason for the rapid adoption was the programs we were using were not working in a lot of cases.

We simply have to have a different and more effective mode of action to get in the mix and Ignite with the LibertyLink system has to be it. First, it is excellent technology, and second, it is the only one on the horizon. The weeds will force this technology to go forward.

We can accomplish much more by being proactive by rotating the technology with the Roundup Ready programs in a prevention mode.

I see a lot written that a LibertyLink system is not a Roundup Ready system. That is true, but they are very similar. I hear some say a LibertyLink program is more complicated than a Roundup Ready system. I have not found that to be the case, nor have I observed that in the research trials I have looked at.

Part of the problem we have with our Roundup Ready programs now is we have made them too simple. In the early years it was easy to get a grower to use a residual herbicide in a Roundup Ready program because we were used to doing it anyway. It was easy to get growers to apply it timely because conventional herbicides had to be applied timely. It was easy to get growers to use multiple applications because they had been used to doing that anyway.

Through the years we learned we could often abuse the technology and our research often supported it — I was a part of that. However, we pushed things to the level of partial weed control or inconsistent weed control and it has come back to bite us.

Both the Roundup Ready and LibertyLink systems provide broad spectrum weed control. Glyphosate is better on bigger grasses and bigger susceptible pigweeds while the same can be said for Ignite on resistant pigweeds, morningglories, smartweed, coffeebean and such.

Both programs can benefit from a residual program. Both programs can benefit from early timing. You can be more liberal with glyphosate timing on some weeds and with Ignite timing on others. However, the first application of either herbicide needs to be in the first 10 to 14 days after emergence.

e-mail: [email protected]

About the Author(s)

Ford Baldwin

Practical Weed Consultants

Ford Baldwin served as a weed scientist with the University of Arkansas Cooperative Extension Service from 1974 to 2001. During that time he conducted extensive applied research trials in rice, soybeans, cotton and wheat, and developed weed management recommendations and educational programs for farmers. Since January 2002, Baldwin has been a partner in Practical Weed Consultants with his wife, Tomilea.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like