[nafex] Apricot Protection

Caren Kirk quirky at videotron.ca
Sat Mar 24 11:03:07 EDT 2012

  Thanks Dan, very interesting. As this is my first year with the 
apricot I think I am just going to play it by ear and see how it goes. 
Everything is up in the air with this yo-yo weather anyway.

I might see about getting some of the product for next year.

Caren Kirk
St. Jerome, QC

On 3/22/2012 11:15 PM, Dan Nave wrote:
> In the NAFEX Apricot Interest Group newsletters, Bob Purvis has written about a product that has the
> ability to give some protection to apricot blossoms and immature fruit. I have taken the liberty of
> excerpting some of this for the group.  See below.
> Dan
> NAFEX APRICOT INTEREST GROUP** November 10, 2005   Newsletter #8
> *
> Agro-K products show promise in frost control.*Agro-K is a Minneapolis-based corporation that
> manufactures a number of different foliar and soil nutrient products for use by fruit and vegetable
> growers.Agro-K had a growers' meeting in March 2005 which I found valuable in terms of acquiring
> information useful to my orchard.There were a number of both conventional and organic fruit and
> vegetable growers present who have been using their products.Given the difficulty that apricot
> growers face with late frosts, I was pleased to find that they have one product that has shown value
> in protecting blossoms from frost:KDL (abbreviation for Potassium (chemical symbol is K)
> Dextro-Lac), makeup is 0-0-24.Agro-K potassium products are derived from potassium carbonate and in
> one case, from potassium sulfate.The manufacturing process combines potassium with sugars (dextrose,
> lactose) and other carbohydrate molecules to make a product that is quickly absorbed, readily
> available, and easily utilized by the plant.The brochure also states that "KDL contains a unique
> activating component designed to enhance the mobilization of potassium within the plant."
> The brochure describing KDL's effects on frost protection states the following:
> "_How can KDL help protect or minimize frost damage?_
> "During spring, as plants begin to grow new green tissue, the demand for nitrogen is at its
> greatest.At this stage the nitrogen to potassium ratio favors nitrogen.During the fall, as fruit
> ripens and plants begin to "harden off" and prepare for winter, the demand for potassium is at its
> greatest.At this stage, the potassium to nitrogen ratio favors potassium.
> "In the spring, when soil is still wet and cold, roots may not operate as efficiently as during the
> summer.In addition to climatic conditions, soil type, pH, etc. can also affect uptake of
> nutrients.These factors, combined with the natural increased demand for nitrogen, may predispose the
> plant to low or deficient levels of potassium.Potassium is an important element in cell wall
> turgor.Having tender new tissue growth with a high nitrogen to potassium ratio creates
> susceptibility for frost damage.
> "Applying KDL immediately before an expected frost can help increase potassium and sugar levels
> within the plant and temporarily put the plant into a more 'winterized' or hardened mode, where its
> tissue is better able to survive cold temperatures without damage.In general, KDL provides
> approximately 5 degrees Fahrenheit of production.If KDL is applied prior to a frost and temperatures
> dip below 27F, some damage may occur."
> "_When to apply KDL_
> "KDL should be applied within 36 hours before a frost is expected.The recommended rate is 1
> gallon/acre.If frosts are expected to occur on two or more successive nights and daytime
> temperatures are expected to remain low (below 55F), KDL does not need to be reapplied.However, if a
> frost is followed by two or more days of good weather (daytime temperatures 65F or greater), the
> plant will metabolize the potassium quickly.If a second frost is predicted after two or more days of
> good weather, for maximum protection, KDL should be re-applied at 1 gal/acre."
> The rate for application with backpack sprayers is 4 oz/gallon, and the recommended amount of water
> to use per acre with 1 gallon of KDL is 30-50 gallons.The cost of a gallon of KDL is $17.25 plus
> shipping f.o.b. Minneapolis.KDL is also recommended for application to apricots 4 weeks and 2 weeks
> before harvest to raise the sugar content of the fruit.
> NAFEX APRICOT INTEREST GROUP REPORTJanuary 16, 2012   Newsletter #14
> *KDL update.*I've used potassium dextrose-lactose (KDL), a foliar spray product produced by Agro-K
> Corp. in Minneapolis, for seven years, both in MN and here in ID.I learned more in 2011 about best
> use of this product, valuable in protecting apricot blossoms and fruitlets during frost events in
> the spring and helpful in improving sugar content when applied 4 and 2 weeks before harvest.
> The current price of KDL is $22/gallon, plus UPS shipping charges from Minneapolis to your
> location.Chapman Mayo, one of the principals at Agro-K, said to use absolutely no more than 3
> oz/gallon, and 2 to 2.5 oz/gallon water may be even better.KDL causes phytotoxicity on young leaves
> and blossoms primarily if it is applied to the point of run-off, where this alkaline product sits
> and dries on the leaf tips.As in past years, I followed the policy of adding household vinegar 1:1
> to KDL before mixing the two with water.My two sprays of KDL (the first was on apricots at full
> bloom, April 8, 2011; the second at petal-fall, April 22) were both at a rate of 3 oz/gallon of
> water with 3 oz vinegar/gallon of water to neutralize its alkalinity.There was absolutely no damage
> at these rates to the blossoms or new leaves on my apricots.
> Use of 4 oz/gallon on foliage and fruits in late June, however, resulted in marking of fruits on
> apricot and especially pear, and significant and rapid damage to pear foliage.If you spray with KDL
> apply it as a mist, or the finest droplets your sprayer can produce.Potassium is very mobile in
> leaves, according to Chapman.AIG member Barry Todd (Littleton, CO), who also grows ultra-large
> pumpkins competitively, said that KDL is used extensively by pumpkin growers also to help size their
> fruits.
> On 3/22/2012 1:08 PM, Jay Cutts wrote:
>   >  It seems like that far north apricots would be real long shot. Here in
>   >  NM they rarely set fruit because of late frosts. Maybe once in 7 years.
>   >  Of course further north your spring might not be as warm as ours.
>   >
>   >  I've never figured out a practical method for protecting tree flowers
>   >  from late frost. I once set my temperature alarm so that if the
>   >  temperature was going to go below freezing (usually 5:30 or 6 am) it
>   >  would wake me up. My plan was to spray water on the trees. But when I
>   >  got out there, the hose was already frozen solid!!
>   >
>   >  Regards,
>   >
>   >  Jay
>   >
>   >  Jay Cutts
>   >  Director, Cutts Graduate Reviews
>   >  Lead Author, Barron's Test Prep Publications
>   >  (505)-281-0684
>   >  10 am to 10 pm Mt Time, 7 days
>   >
>   >
>   >
>   >  On 3/22/2012 11:54 AM, Caren Kirk wrote:
>   >>     Following Steve's e-mail about early pruning due to excessively warm
>   >>  weather I am starting to freak out about the apricot I planted last
>   >>  spring. Being that it's the first winter here and then with this yo-yo
>   >>  temperatures, does anyone have any suggestions on how to protect the
>   >>  blossoms. I'm a long way from that right now, the buds haven't even
>   >>  begun to swell yet but it won't be long with this warm weather and I
>   >>  like to be prepared!
>   >>
>   >>  Any advice appreciated.
>   >>
>   >>  Caren Kirk
>   >>  St. Jerome, QC
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