top of page

October 2015


                Weed control in the tree row is much more than cosmetic. There is a measurable benefit to tree growth from the reduced competition for water and nutrients. Mouse populations are lower when there is little or no weed cover for them in the tree row  The most economical time to control weeds, regardless of the material that you choose, is in the fall before leaf fall or with the leaves raked away, up until the ground is frozen.  I once did an early December application in Cedaredge.  The next spring you could see to the row where I had sprayed. This application will control the fall germinating annuals that otherwise will require treatment in the spring...your VERY, VERY busy spring!  It is always easier and cheaper to prevent a problem than to cure it.


                The constant factors in safe and effective weed control are calibration, uniform coverage and timely incorporation of residual materials into the soil by irrigation or rain. Some residual herbicides can injure trees if the application rate is higher than the immobilizing ability of the soil and they are carried deep enough into the soil to contact tree roots. In other words, light soils are more risky than heavy soils. I know that a number of you use backpack or 4-wheeler tanks to spray weeds with contact herbicides.  Using a hand wand to apply residual materials is risky at best.  It’s next to impossible to get a uniform, proper amount applied.  Some labels do not allow for application with a hand wand. Check to be sure your nozzle style and configuration delivers a uniform pattern on the soil surface. Account for the overlap that you will have in the center of the tree row. Don’t double the actual rate of applied material in this area by hanging extra nozzles or increasing nozzle size on the end of the boom.


                 Remove large weeds that prevent uniform spray coverage of the soil surface, the ‘shadow’ from existing weeds will be where your weed control will fail first next year. Do not spray over the top of a heavy leaf drop; many of the small germinating annuals will be protected from the contact materials in the mix. If a windstorm moves the leaves before the next good rain, your residual material may be gone also. The cleaner the soil surface at the time of application, the more effective the material will be. Organic matter on the soil surface will bind up some of the material before it can get into the soil. If you still have irrigation water available, incorporate the material soon after application with an irrigation of  ¼” - ½” . This will ensure no weather degradation and allow the residual control material to bind close to the soil surface where it is most effective. A long irrigation set will drive the material deeper into the soil, resulting in a weaker weed barrier and possible damage of young trees.


                 If pearleaf blister mites were an issue in your pear blocks this season, we’re coming up on the perfect time to get control over them for next year.  The mite itself is the size of a small rust mite.  It is white in color and elongated, unlike the dull yellow wedge shape of the Rust mite.  Leaf damage shows up as white blisters that decay and turn black.  When you look at the blister with a 16X – 20X hand lens you can see a small exit hole in the center of the mound.  Fruit damaged soon after the pears form, appear as red lesions along the upper end and stem.  Check the following address to see an example.   


As the fruit develops the damage becomes a sunken russeted area.  They spend the dormant season under bud scales, emerging  as soon as the first green growth peaks out.  Blister mite becomes active at temperatures lower than those required by Rust mite.  A conventional dormant oil with the proper insecticide will usually clean them up for the season.  If you’re farming by organic standards then the Fall is your only shot.  Lime/Sulfur (sulfur alone won't do the job) just before leaf drop is the ideal window.


There are three critical times growers need to protect crops against cold injury: 


• Spring’s late frosts (early growing season)

• Autumn’s early frosts (late growing season)

• Winter’s very cold temps (dormant season)


Over the past several winters we've collected peach buds and funded the tests to determine how hardy they are at various points through the winter.  We’ll be doing that again this year, likely starting in November.  A note of thanks to Horst at CSU's Orchard Mesa research center for the technical expertise and equipment to run the tests.




Cropworx owns and reuses the barrels that we deliver your dormant oil in.  To ensure you receive a clean product, we steam clean them inside and out before each use.  This requires a bit of handling (expense) on our part, but is far less expensive than buying product in new drums each year.  To help us keep your cost down, please make sure your drums are completely empty.  If we happened to miss any empty barrels at your farm, let us know so we can pick them up.  THANKS!



“We can never do a kindness too soon, since you never know how soon it will be too late!”      Emerson.


“The budget should be balanced, the treasury should be refilled, public debt should be reduced, the arrogance of officialdom should be tempered and controlled, and the assistance to foreign lands should be curtailed, lest Rome  become bankrupt.  People must again learn to work instead of living on public assistance.”  - Cicero 55, BC

bottom of page