Herbicide resistance – Not just about the weeds

Bob Schroeder
CPS Tangent

For several years now we have been talking about and using strategies to avoid herbicide, fungicide, and insecticide resistance in our crops amongst our many pests.  The introduction of glyphosate (Roundup-ready) resistant plants was one of the first technologies to really accelerate the resistance of some of our weed species in the crops and on the species where it is used.  As a result of the use of so much glyphosate, it has sped up the resistance of weeds and at the same time affected greatly the supply and availability of glyphosate to the rest of agriculture.  We in the Willamette valley this past year were affected again by product tightening of glyphosate as well as the extreme tightening of another product, known in our market as Rely and Reckon, and Liberty in the rest of the U.S.  Liberty too is used in an effort to combat glyphosate resistant weeds in other major U.S. crops such as corn and soybeans.  The result of this was the loss of available Rely for use in our fescue and ryegrass crops as well as for sucker control in hazelnuts.  Despite other sources of some of these products, supplies have continued to be limited because of the large volumes committed to the major crops while our NW crops are considered minor in the acres produced.

The latest product to come up on the radar screen that we have used extensively here in the NW is Dicamba, branded as Banvel, Rifle, Clarity, and a host of other generics.  Dicamba resistant soybeans have given soybean producers another tool for combating glyphosate resistant weeds in their production but it is having a big impact on product supply and availability to all the other crops.  With Soybean acres in just the U.S. surpassing 77 million acres, if only 1% of the acres account for a single Dicamba application, it is more than double the product the whole Oregon grass seed industry uses.   

Fall Pests in the Willamette Valley

Bob Schroeder
CPS Tangent

A number of common pests are reeking havoc in Willamette Valley fields this fall.  Pressures are heavier in some areas and crops than in others but even small populations are wide spread this fall.  

Cutworms - Agrostis species
The eggs are a pearly white, rounded and about 0.5 mm in diameter.  You will find them in clusters or singly, laid on vegetation, moist ground around plants, and in cracks in the soil.  One CPS fieldman even found clusters of them on his field flag.   The larvae (caterpillars) can be plump, smooth caterpillars that are greasy in appearance and can range in color from grey to brown or black.  The larvae curl into a C shape when they are disturbed and remain motionless for a short time.  They can blend in well with the soil, making them difficult to distinguish.  They commonly hide just below the soil surface or in residue during the day.  
Cutworms generally feed at night or during overcast and foggy days of which we have had many in October.  Young larvae feed on plants leaving small irregular holes in the leaves.  Larger larvae may completely cut through the stocks of plants.  When populations are heavy, they can destroy as much as 75% of a crop and are particularly tough on new seedings.  Most damage occurs between June and November.  There are several control options.  Consult with your fieldman for the most effective means of control.  For additional information follow the link below.

Cutworms in the Pacific Northwest

Grass Seed Wireworms
Wireworm larvae are the damaging stage of this pest that are yellow-brown and up to 0.5 inches long.  Larvae feed on the roots and into the crowns of plants, killing or severely stunting their growth.  The damaged seedling stands often appear yellow, and the plants eventually turn brown and die.  The larvae migrate up and down in the soil profile as moisture changes.  

Grass Seed Wireworm