Question of the Week – Heat Stress

This week, the question was: What is what is going on with the different sized beads and color variation in this broccoli head?

This broccoli head is showing a symptom known as “cat eye” where there are clusters of small, lighter-colored beads surrounded by larger, darker-colored beads. This is a common symptom of heat stress in broccoli. This is more often seen in broccoli grown in the spring as temperatures heat up during head formation, especially if spring temperatures heat up quickly. The head pictured here would be unmarketable. Heat has been one of the biggest challenges to growing broccoli on the east coast; therefore, selecting heat-tolerant varieties (pg. 49) is extremely important when planning a broccoli crop.

This week’s question is from Justin Ballew, Extension Fruit and Vegetable Research Associate.