The figure of the constellation Boötes carries a sickle in his left hand. (A sickle is an tool with a short handle and curved blade for cutting grain or grass.) The figure represents the reaper of the harvest, the one who will judge between the grain that is brought in and the chaff, or waste, that will be burned. Boötes is from a root meaning to come, and carries the idea that a judgement day is coming.
The following poem is in the old style called alliterated measure. Many of the terms are no longer familiar. Looking them up will be a good language lesson for the day.
Boötes the Ploughman
The ploughman prepares a plot to sow,
Smoothly strews the seed to grow
Waters and waits, watching his field
As his grain greens and gains in height.
Ranging rank and ragged are tares
Allowed to linger, later to burn.
Then scythe and sickle he sets to the task
And forth from the field he faithfully brings
The stalks to stack and store, then thresh.
Goodly grain he garners at last,
But chaff, cherished not, he chooses to burn:
Boötes the omen of oncoming harvest.
"His winnowing fork is in his hand, and he will clear his threshing floor, gathering his wheat into the barn," Matthew 3:12.