As kids go back to school, operations have started the shift from summer crops over to fall crops, which includes the transition from peaches to apples. Peaches are in the ‘Cresthaven’ window, with cultivars like ‘Encore’, ‘Autumnstar’ and ‘Laurol’ yet to finish out the season. Apples are in the ‘Gala’ window, with ‘Honeycrisp’ harvest just starting.
It has been normal hot, but unusually humid in the St Louis Metro East and our IL State Climatologist, Dr. Trent Ford, just confirmed that perception. He reported St Louis Lambert Airport has had over 900 hours this summer so far with a dewpoint above 70°F (~50% of the entire season), which is the 5th highest on record and the highest since 2010. Plant surfaces have been staying wet well into the day, which translates into slow drying conditions following pesticide sprays, which has resulted in increased reports of phytotoxicity on leaves, especially when adjuvants were in play. The southern half of Monroe County is abnormally dry which puts an additional stress on plants trying to cool themselves. Transpiration normally works under the premise the air is drier than the soil which allows the transpiration stream to pull water through the plant out into the air. When the soil is dry, and the air is super humid, everything is backwards and the process is not as efficient cooling the plant, thus you see folding of leaves and/or wilting in response to the heat and intense sun. The rest of the region has fared better with timely rain, but still in need of that next rain shower.
Sunflower mazes, blueberries and blackberries are finished. Not all growers run a full season, so some growers have finished with sweet corn and peaches. Tomatoes are still in harvest, but ripening has slowed due to heat. In the next few weeks, fall agritourism activities like corn mazes and pick-your-own pumpkins will open for the season.