Crambe Tolerance to Low Temperatures

The seedling crop can tolerate temperatures in the low 20's for several hours. For example, at the Carrington Research Extension Center in 1990, temperatures of 22-23 degrees were present for about 5 hr, followed by 35 degrees as the high temperature for the day. These temperatures occurred when crambe was in the cotyledon stage (tips of true leaves just visible). Later, the cotyledons turned completely brown and the tips of the true leaves also were brown. However, the true leaves eventually emerged and the plants developed normally. Also, during the week of May 24, 1992 at the Carrington Center, low temperatures of 30 degrees for 4 hours were tolerated by crambe in the cotyledon to emerging true-leaf stage. With this data in mind, delay any decisions to destroy a frost-damaged crambe stand until the crop's condition is known. Allow about 7 to 10 days to determine if normal regrowth is occurring.