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April 2010


Planting trees this year?   A word of caution if you sat in on Dr. Scott Johnson's talk at the hort show.  Scott told of his success at getting zinc into young trees by adding a small amount into the hole at planting time.  I emailed him the other day to confirm the rates.  This is his response: “I talked about 1/8# Zn Sulfate per hole – but I just went and looked at some treated this way in January at planting and they don’t look right.”   So now a phone call was in order!  He told me that he has backed off completely from Zn Sulfate.  The test trees have continued to not do well.  Oh well...back to the drawing board.


Here's a few products that may be new to you: 

Flyin Hi N – A  certified organic, soluble source of nitrogen for foliar applications.  It replaces the now extinct

fish powder.

Matran EC – A certified organic burn down herbicide made of clove and wintergreen oils.

Isomate CM Flex –  Similar to the CTT split tube but with a single tube load.  Keeps point sources higher with an                                     easier method of application.

Treevix – A new postemergence broadleaf herbicide that has residual properties.  Adding this material in with 

             Roundup or Gramoxone can add a number of weeks to your weed control.


I expect (hope) that soon the skies will clear and bloom will be upon us.  But, if it continues to be wet, stop and consider what disease problems that will mean for your orchard.  Is your coryneum blight and/or brown rot  program in place?  Changes in the weather should give you a heads up that you may need to change your crop protection plans.  Wilsonomyces carpophilus, AKA Coryneum blight is far easier to prevent than eradicate!  Always be proactive !  The absence of blight at the packing shed costs you nothing!


“If, from the more wretched parts of the old world, we look at those which are in an advanced stage of improvement, we still find the greedy hand of government thrusting itself into every corner and crevice of industry, and grasping the spoil of the multitude.  Invention is continually exercised, to furnish new pretenses for revenues and taxation.  It watches prosperity as its prey and permits none to escape without tribute.” 

            Thomas Paine, Rights of Man, 1791


Every spring I get asked “How cold is too cold to spray dormant oil?”  The text book answer is 45ºF.  A bit of common sense also figures in.  Is the temperature on the rise, or decline?  Is it windy, damp, cloudy, etc.  Pay attention to freezing temps during the 48 hour period before application and for 24 – 48 hours after.  If present or predicted, hold off. 


It's common to make an application with a tank mix of several different pesticides and formulations.  There's a specific mixing order that will help keep you out of compatibility problems.  In other words, spending the rest of your day cleaning out your sprayer!  1) soluble packets,  2) wettable powders, or water dispersible granules,  3) flowables,   4) emulsifiable concentrates,  5) oils.   Always, always always add oils LAST!



Are you thinking that last December’s low temperatures took care of your pest problems? The following information is from  a college textbook,  Destructive and Useful Insects by Metcalf, Flint and Metcalf.  Regarding codling moth: “They remain dormant and are able to withstand low temperatures.  A drop in temperature to – 25°F or below however will kill many larvae.”  I suspect that if winter temps take care of your codling moth problem, your harvest worries will also be over!

A few tends in pest problems that I see happening across the area:  Peach silver leaf mite, Powdery mildew on cherry and peach, Crown Borer and Cystospora canker (gummosis).  Choice of insecticides, proper timing and /or coverage, the solution for each is different or unknown.  If you’re battling one of these, think back over the last several years and look for changes in a program.  Did you buy a new sprayer?  Change pruning techniques.  Insert a new insecticide chemistry.  Increased your spraying speed to cover that new acreage.  I’ve worked up an aggressive new mildew program for cherries.  There is a number of materials being tried on gummosis, some with success, some without.  Give me a call if you’re orchard is on the above list. 


Spring is the most stressful time of the year for any fruit tree.  Your orchard is drawing from reserves as it progresses through bloom.  Soil temps are cold and limit nutrient availability.  Fruit size is partially determined by the number of cells each fruit contains.  Cell division occurs immediately after bloom (from 14 to 28 days) when the stress is at a peak.  Healthy, well fed, trees are better able to handle and size large crops, survive winter injury, and pull buds through spring frosts. Next years’ flower buds are determined this season.  Keeping a tree well fed is a year round program.  Properly timed foliar applications of nutrients can help relief the stress!


Delayed dormant: Zn, Mg & B;  Pink, Petal Fall & Summer: N, P, K & CA;    Fall: Zn, B, & N


Calcium in adequate amounts is important for the formation of strong cell walls. If adequate calcium is not available when cells are being formed the fruit will be more likely to develop problems later in the season if they are subjected to any stress. At maturity, with cell walls fully stretched, fruit deficient in calcium will have less firmness and begin to show internal disorders more rapidly than fruit with adequate calcium. Fruit with high calcium is normally firmer and retains good eating quality in storage longer.  But there is a real risk that fruit will be low in calcium during cell division. Here’s why.  Cell division and development takes place early in the season when soil temperatures are cool and tree roots are not very active. Very little calcium is being picked up from the soil.   After the soil warms up and the roots begin to actively support growth, most of this newly available calcium from the soil is passively transported to the most actively growing parts of the tree, leaf expansion and shoot growth, the more slowly expanding fruit cells.  What's the take home message here?  You have a window of opportunity open NOW.   Add calcium to any spray applications made during the cell division period.


 “Burn down your cities and leave our farms, and your cities will spring up again as if by magic; but destroy our farms and the grass will grow in the streets of every city in the country” - William Jennings Bryan





Larry    234-3424


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