Wednesday, July 25, 2012

Herbicide Options for Double-Cropped Soybeans

With the current high price of soybeans, many GA growers are planting soybeans after field corn.  Thus, I have received many questions about weed control options for this situation.  Please consider the following:

1) My recommendations for weed control at this point in time are very different from early/normal planted soybeans. 
2) My primary concern is crop rotation.  If wheat is to be planted this fall or field corn is to be planted next spring, herbicide options may be limited depending upon the application date.
3) Table 1 lists the current labeled crop rotation restrictions for common soybean herbicides.
4) In order to prevent any major crop rotation problems, I would suggest a PRE application of Dual Magnum (or generic) followed by an EPOST application of glyphosate + Cobra or Ultra Blazer (RR soybeans).
5) Valor would be an excellent choice in fields where a POST application of Cobra, Prefix, Reflex, and Ultra Blazer may not be needed.  If we are going to protect Valor, growers must avoid PRE applications of Valor followed by POST applications of Cobra/Prefix/Reflex/Ultra Blazer. PPO abuse for sure!
6) If field corn will be planted next spring (~8 months), avoid the use of Canopy, Envive, Prefix, Pursuit, and Reflex.