They are called here, though I do not know why, ratoon oysters.
"Letters of a Traveller" by William Cullen Bryant
The first season is denominated "plant cane," and each of the subsequent growths, "ratoons.
"The Commercial Products of the Vegetable Kingdom" by P. L. Simmonds
The first is called plant cane; the second is known as first-year stubble, or ratoon.
"Agriculture for Beginners" by Charles William Burkett