Spring weather is unpredictable. One of the major risks associated with strawberry production is cold damage in the spring. Open strawberry flowers can not tolerate temperatures lower than 30°F, popcorn stage flowers and tight buds may tolerant temperatures low to 26 and 22°F, respectively. If strawberries are in the early blooming stage, the damage might be delayed harvest. However, if strawberries are in full blooming stage, low temperatures may cause dramatic yield loss. This is because inflorescences are initiated at day length <14h (June-bearing cultivars). If all the flowers were killed by low temperatures before setting fruit, there would be no more flowers for the year.
In this article, we update the cold damage that happened last week on plasticulture strawberries in Vincennes, IN. Figure 1 is the recorded temperatures (°F) at the height of strawberry canopies from 2:00 pm Apr. 13— 1:00 pm Apr. 18. Temperatures dropped below 30°F and lasted for about 8 hours on the night of Apr. 15. The lowest recorded temperature was 24.5°F (Figure 1). Not surprisingly, the temperature killed all open blooms. Some ‘popcorn’-stage flowers were killed by the low temperatures (Figure 2).
Row cover (1.5 oz/sq) was used for cold production. Under row covers, temperatures were about 30 °F on the coldest night. Very few strawberry flowers were damaged under row covers. The cold protection strategy successfully saved open strawberry flowers during this frost event.
Figure 1. recorded temperatures (°F) at the height of strawberry canopies from 2:00 pm Apr. 13— 1:00 pm Apr. 18.
Figure 2. Cold damage on ‘Popcorn’ stage strawberry flowers.