Stretching is a phenomenon that causes the stem of a plant to stretch long and thin. This may result in the plant not being able to support its own weight when it matures. Stretching can occur due to genetics but lighting, temperature, climate, and stress factor in as well.

Learn all about stretching and how to prevent it:

• How To Deal With Stretching Marijuana Plants

More plant problem definitions:

Bud rot | Stress | Pests | Diseases