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Supplemental Applications of Phosphorus and Potassium Benefit Pecan Production

Growers are taking advantage of soil nutrients from prior years’ applications.  “It’s a tough time for our growers considering inflationary fertilizer costs”, says Gary Veal, Technical and sales agronomist for Plant Food Systems, Inc. 

Some growers are reducing the soil applied P&K. Some orchards have banked enough P&K from prior years to skip soil applications in 2022.  Pecan trees benefit from applications of Sizer XL.   Phosphorus and Potassium are key in the pollination period and beyond.  Quite simply Sizer XL is pure, soluble and immediately available Phosphorus and Potassium!

As the season progresses past pollination and into June the pecan tree will abort nuts beginning in June.  The tree knows that it can’t take all the nuts to harvest so we experience the first nut-drop in June.

In June, nut elongation and expansion put a stress on available nutrients. The pecan tree is utilizing nutrients beyond what the tree can provide. Coupled with flushes of new leaves, nutritional stress of P&K available to support the nut-load is something we can address.

The pecan tree and nut-crop can benefit from supplemental, foliar applications of P&K.  The best timing for application of Sizer XL is July and August.  The applications support new leaf flushes that rob nutrients important to nut production. Trials have demonstrated the benefit from foliar applications of highly soluble forms of P&K found in Sizer XL.  

In sponsored trials, size and quality were improved. Applications in early July and early August support growth and health of the nut crop.  

Plant Food Systems, Inc., recommends two applications of Sizer XL prior to nut-fill.  Make the first application around July 4 (an easy date to remember) at one gallon Sizer XL per acre.  The second application should be timed for early August, around 30 days after the first application.  

The two Sizer XL applications will insure adequate P&K prior to nut-fill.  Grower trials with Sizer XL have resulted in an increase in size and shell-out percentage.  In 2020, we had an increase of 10% on Desirable in a 10- acre managed trial.  The Desirable went from 44 to 39 nut count.  Another 2020 grower trial resulted in a 5% increase in size on Sumner variety. 

In 2021, a grower trial resulted in a 4% increase in size on Caddo, but interestingly the shell-out percentage went from 52 to 54%.  The difference in shell-out percentage had a value of $100 per acre based on a 1500# yield.    

Sizer XL provides highly soluble and totally plant available P&K that goes to work immediately.  Solubility of nutrients is the key to tree availability.    Sizer XL can be tank-mixed with Kphite 7LP or other fungicides and insecticides.  


Gary Veal is Technical Sales Agronomist for Plant Food Systems, Inc.