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March 2015




New Products


              The Cropworx team is always on the lookout for products that will bring additional benefit through lower cost, increased efficacy, ability to avoid resistance, etc. 


              If your GAP program requires the use of a sanitizer Cropworx is now stocking SaniDate 5.0. SaniDate 5.0 is broadly labeled for hard surface sanitization and disinfection, as well as fruit and vegetable wash treatments to eliminate human health and plant spoilage pathogens on contact.  SaniDate 5.0 is also NOP compliant and OMRI listed for organic production.



              This winter I came across a series of research reports that looked into the results of different calcium products on the market.  Calcium chloride performed the best in all trials.  This is due to the amount of calcium contained in the product.  Its common knowledge that using this source of calcium has two drawbacks, foliage burning and it’s hard on equipment.  The statistical results from the other forms tested did not show a significant difference between them.  The key difference comes in their ease of use.


              Cropworx will carry three calcium products this season: Metalosate Ca (6% amino acid chelated ca), Mor-Cal (34% calcium chloride) and a new product to our lineup, Nutrichem Calcium (6% citric acid chelated calcium).  The decision to no longer carry Nutri-Cal is due to the information contained in the research reports and the ability to provide Nutrichem Calcium at a 25% less cost.



Early Season Sprays


               Early in the season there’s typically a need to spray as a preventive measure for issues such as mildew and mites.  Staying ahead of the problem can spare you a lot of headache as the season progresses.  Depending on what your spray program consists of, you may have already touched on both of those events with a dormant/ delayed dormant horticultural oil spray.  Click on the following link for more information on that;




               In peaches, dormant oil sprays aren’t enough to smother and kill the overwintering Peach Twig Borer (PTB) nestled in its hibernacula (Latin, "tent for winter quarters").  The hibernaculum is typically located in crotches of 1- to 3-year-old wood, in pruning wounds, or in deep cracks in bark. The overwintering site is marked by a chimney of frass (bug turds) and is especially noticeable when first constructed or before winter rains set in. If you experienced PTB damage in your fruit or know that there is a presence in your orchard of this pest, adding 8 oz of Asana (per acre)with your dormant oil spray is often effective at gaining control over this critter.  The Asana is stout enough to penetrate the hibernaculum and kill the pest before bloom occurs.  If not controlled, the PTB migrates up twigs and branches where they attack newly emerged leaves, blossoms, and shoots. As shoots elongate, larvae mine the inside, causing the terminals to die back. Dead shoots are known as shoot strikes or flags. 


               If you missed the delayed dormant spray timing, there is another opportunity to control PTB, and that comes between full bloon and shuck split.  Within an IPM program, the preferred management strategy for peach twig borer is well-timed treatments of environmentally sound insecticides around bloom time. These include Dipel, Entrust or Success, Intrepid, Delagate  and Dimilin.  Delegate, Success and Entrust are great choices as they  provide control over thrips as well

Bloom time sprays on peaches are a great time to throw in a fungicide for coryneum blight  and something for  nutrition as well!




               Powdery mildew is distinguished by superficial, white powdery growth on leaves and shoots that results in the stunting and distortion of young growth. Infected fruit are stunted and russetted, and fruit set may be reduced. This is a major foliage disease of apples. The fungus overwinters in terminal buds that are white, flattened, and pointed. Disease development is favored by warm days and cool, moist nights.

               To prevent buildup of the fungus and damage to the crop early in the season, sprays timed at half inch green and pink are ideal.  If powdery mildew continues to be a problem in the orchard, apply additional treatments until terminal growth ceases.  Take advantage of your time spent spraying for mildew by adding some nutrition.  At pink, it’s a great time to throw in any or all of the following; Urea, Calcium, 20-20-20 and maybe some boron to help with fruit set.


See the April 2014 Newsletter for more on this subject.!april-2014/cm5j


               If woolly apple aphids were a problem, keep in mind they’re coming out of the ground and heading up the tree at about half inch green.  A slurry of Diazinon mixed with a sticker sprayed on the trunks is effective at preventing/ killing them before getting to the canopy.  This job is best done with a handgun.  The more water you apply the better it works.  Though it may not be enough to eliminate the problem, it certainly gives you a head start on control early in the season.



               Surfactants, also called wetting agents and spreaders, physically alter the surface tension of a spray droplet. For a pesticide or nutrient to perform its function properly, a spray droplet must be able to wet the foliage and spread out evenly over a leaf. Envision a drop of water on the kitchen counter and how it sits in a “dome” shape.  Surfactants cause the dome to flatten out.  They enlarge the area of product coverage, thereby increasing the plants exposure to the product applied. Surfactants are particularly important when applying products to waxy or hairy leaves. Without proper wetting and spreading, spray droplets often run off or fail to adequately cover these surfaces.  Surfactants help pesticide sprays penetrate plant cuticles.   Every tank of spray that I apply each season has some type of surfactant in the mix.  The most commonly used in our area are Bio 90 or an oil of some type.


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