Monsanto unveils Roundup Ready Xtend crop system

The process has started to roll out Monsanto's new Roundup Ready Xtend Crop System for use in soybeans fields once regulatory approval is received.

Ag dealers and farm media recently attended a field day at a plot near Arthur in eastern North Dakota that highlighted research being done in several areas with Roundup Ready Xtend soybeans. The system will eventually allow growers to use dicamba on the crop and thereby providing another mode of action for weed control in addition to glyphosate.

According to Monsanto officials, the new crop system is designed to help maximize control of resistant and tough to control weeds through effective, sustainable weed management. The main features this new cropping system will offer include:

- Control of resistant and tough-to-control weeds with a dual mode of action herbicide

- Enhance application and planting flexibility

- Lengthen the window for post applications and give enhanced residual benefits

- Provide residual control for up to 14 days

- Deliver proven genetics

-Maximize yield potential

The two new formulations being introduced by Monsanto are Roundup Xtend and XtendiMax, and both will be matched up to the Roundup Ready 2 line of soybeans. According to Jack Brodshaug, a technology development representative for Monsanto, the Roundup Ready 2 soybean line gives over a 4.5 bushels per acre advantage over the first generation Roundup Ready soybeans and a 6.0 bushel advantage to LibertyLink soybean varieties.

"By using the combination of Roundup Xtend herbicide with Roundup Ready 2 Xtend soybeans you are going to get your optimum yield potential along with optimum weed control," Brodshaug said.

"This is the first trait we are bringing out that has a 'stack'. What we mean by a stack is that it has the Roundup 2 trait and the dicamba brought together in one bean," said Steve Valenti, a Monsanto technology development rep.

Valenti also noted that the dicamba being developed by Monsanto has a lower volatility than the earlier versions, which is important since dicamba vapors can be harmful to certain other crops.

Once the new, low-volatility formulations of Roundup Xtend, a premix of dicamba and glyphosate, and XtendiMax, a straight dicamba formulation, hit the market, growers will see several changes in the herbicide label in regards to application regulations, Valenti noted.

These changes include:

- Spray droplet size. Nozzles will need to produce droplets sizes ranging from very coarse to ultra-coarse in size to minimize drift, which will reduce off-target movement of the spray. Research has shown that weed control with dicamba will not be sacrificed by using the larger droplets.

- Wind speed. Application will need to be made when wind speed is between 3 and 10 miles per hour. Higher wind speeds will increase drift potential, while speeds lighter than 3 mph tend to be unpredictable and variable in direction and temperature inversions can occur. Spraying is prohibited when a temperature inversion is present.

- Boom height. Operators should maintain a boom height of 20 inches above the crop canopy. Excessive boom height can increase the potential for spray drift. It's important to maintain an appropriate boom height that minimizes the distance to the canopy and yet allows for proper spray pattern development for complete coverage

- Ground speed. Ground speed needs to be less than 15 miles per hour. If ground speed is too fast for soil conditions, such as rough ground, the speed should be reduced even further to minimize bouncing of the nozzles, which can result in poor coverage and excessive drift.

- Maintain the required spray buffer. Spray buffer distances haven't been determined yet, but once they are they will included in the label directions. The spray buffer will be a certain distance between the closest point of direct dicamba application and the nearest downwind boundary of any off-target sensitive area.

- Spray when weeds are less than 4 inches tall. Best weed control is obtained when the weeds are in their early growth stages

- Triple-rinse sprayer tank cleanout. After rinsing the tank and all parts of the sprayer such as hoses, nozzles, strainers and valves with clean water, the entire sprayer will need to be rinsed three times with a sprayer cleaning solution. After a final rinse with clean water the sprayer will be ready to return to service applying a different product.

This triple-rinse requirement is likely to cause some complaints for farmers, since it could take slightly over an hour to complete the process. But Valenti said it is necessary to make sure all dicamba residue is flushed from the sprayer before spraying dicamba-sensitive crops. This will be a label requirement.

Full label clearance for the glyphosate-dicamba product isn't expected until the 2015 growing season, according to Brodshaug. During the 2014 growing season select farmers will be taking part in specially permitted "Ground Breakers" field trials that will serve two purposes. It will allow the Roundup Ready Xtend Crop System to be tried on a commercial-scale, rather than just plot sized trials, and tours of those Ground Breaker field trials will showcase the weed control benefits, proper system use and application requirements of this new crop system.