October 8, 2003 | By: Aimee D. Heald

Mother Nature just won’t let up on burley growers in 2003. She kept them from planting on time. Then they had to deal with a late and wet cutting, causing more green tobacco sickness than normal. Now the unseasonably cool fall weather means more problems.

“The last thing growers needed was an early cold snap,” said Bob Pearce, University of Kentucky Extension tobacco specialist. “But that is just what we got.”

He said relatively large acreages of burley remained in the field when the first fall frost hit many parts of Kentucky, and even though the cold spell appears to be over for now growers will continue to feel its effects.

“During a frost, water inside the leaf freezes and expands, causing the cells to burst and leak out all over the leaf,” he said. “One of the compounds that leaks out is chlorophyll, the pigment that causes plants to be green. Once chlorophyll leaks out, it may dry very quickly without breaking down and that can cause the leaf to have a green appearance even after curing.”

Growers who got their crop into the barn before the cold snap may still see some green in their cured burley. Pearce explained that the ideal temperature range for burley curing is 65 to 90 degrees Fahrenheit. Chemical reactions that cause color changes occur faster at higher temperatures. Low temperatures in the first week of curing often result in green color regardless of humidity, he said.

During cooler weather growers don’t have to worry as much about houseburn, so tobacco should be housed closer together and farmers should close barns up to minimize ventilation and slow the drying rate. Pearce said yellow and light-colored tobacco usually can be improved by time and cycling in and out of case, but once a green cast is set it is difficult to remove.

“Green is just not a desirable color for cured burley tobacco,” he emphasized. “So growers will need to be careful during stripping and grading to separate green tobacco. Typically it’s much better to separate green leaf and to keep it from dragging down the grade and price of the entire crop.”


Writer: Aimee D. Heald 859-257-4736, ext. 267
Source: Bob Pearce 859-257-5110