Symptoms of flax wilt: the top leaves turn yellow after seedling infection, and then wither; The stems are grayish brown or brown, contract inward, rot at the base, wither and die like fire. The root of the adult plant is grayish brown, the branch root is necrotic, the underground part is yellow and short, the leaves are withered from bottom to top, the top is drooping, and the leaves turn from green to yellow from bottom to top, so that the whole plant withers, dies and stands upright.

The stems were brown, and the diseased plants died. The base and roots rot and are easily pulled out of the soil. When the diseased stem is cut, the vascular bundle turns brown.

Under humid conditions, pink molds often grow on the roots of diseased plants. At the fruiting stage, the basal tissue of the stem is necrotic, the plant wilts, the vascular bundle of the stem browns, the root hair and lateral roots decrease, and it is easy to pull up; Capsule seeds are small and few, with poor quality and bacteria.