What is an indicator that cotton is ready for harvest?

When evaluating whether cotton is ready for harvest, the most reliable indicator is that the bolls are cracked open. This phenomenon signifies that the cotton fibers have matured and are ready to be picked. When bolls crack open, it indicates that the seeds inside have developed fully and that the cotton lint has reached its optimal moisture content for harvesting.

Other factors such as the falling of leaves or the plant turning yellow may indicate stress or certain growth stages, but they do not specifically indicate the maturity of the cotton bolls. Additionally, the height of the plant does not directly relate to the readiness of the cotton for harvest; it is rather a factor of the growth environment and conditions. Thus, observing the cracking of the bolls provides the clearest sign that it is time to harvest the cotton.