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Commercial Fruit and Vegetable Growers

St. Louis Metro East Update: New Apogee recommendation available

pink stage of apple flower development

Based on research by Wallis and Cox with Cornell University and with support from BASF, an Apogee Sec. 2(ee) Recommendation for Illinois apple growers is now available.  The recommendation now allows for the first application of Apogee to be applied between the pink stage of flower development and 1 to 3 inches of new growth.

The St Louis Metro East experienced a very unwelcomed freeze event the morning of March 18, with temperatures reported at this writing between 25°F and 27°F.  Several apple varieties were as far along as pink, and research shows apples at pink can tolerate down to 28°F before suffering a 10% loss, but just 3 more degrees down to 24°F (full pink) to 25°F (first pink) can result in a 90% bloom loss.  The saving grace might be the need for only 5-10% of apple blooms to set a full crop.  Peaches were as far along as full bloom, and the critical temperatures for 10% bloom kill at that stage is 27°F and 90% bloom kill at 24°F.  This is the second cold injury event peaches have experienced this year; the first occurring in mid-January when temperatures dropped as low as -10°F. Growers have already reported cutting some blooms and finding signs of internal injury, but the full extent of the damage won’t be known for a few days yet; as temperatures rise, and any damaged cells begin to shrivel and brown.

pink apple blossom
'Liberty' apple at first pink.