This disease was observed mid-June 2020 on Long Island in a small garden planting of a Chinese specialty vegetable, Hon Tsai Tai (Brassica rapa). This Asian green is also known as Kailaan and purple-flowered Choy Sum. Plants were past prime at the time. Conditions had been warmer and drier than typical. Symptoms have not been observed in commercial plantings of other crucifers, which are different species (mostly Brassica oleracea). Powdery mildew has been observed in winter-grown kale (Brassica oleracea var. sabellica) in the region.
