1961 18 Jan, Guardian (cited after OED):

When people continue to use the 'R' word, it's hurtful," Seckler added.

However, the procedure has been applied only to those below the threshold and who might move up, and not to those just above, who might move down. This has had a very distorting effect on the distributions.

[T]he only reason that buckwheat is considered valuable as a honey plant, is because it blooms generally in dry weather late in the fall, when the difference in the temperature between two o'clock in the day and two o'clock at night is sufficient to favor the production of honey.