Blossom Drop
The flower stem and calyx turn yellow and the flowers or small fruit abort and drop off. In jointless varieties, the flowers may remain attached.
Tomato blossom drop may be caused by stress conditions such as temperatures above 32°C (90°F) daytime or 21°C (70°F) nighttime or, below 20°C (70°F) daytime or 10°C (50°F) nighttime. Other contributors may include high relative humidity, windy conditions, improper nutrition, disease or insect damage.
Some varieties are less susceptible to blossom drop or to high or low temperatures.
Tomato plants may naturally lose blossoms when already carrying a heavy fruit load. Blossom drop is not generally of economic concern.
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