What to Do When Fritillaria thunbergii Gets Soft Rot? Symptoms and Control Methods

Fritillaria thunbergiiSoft rot is an important disease affecting Fritillaria thunbergii during its summer-over seed retention. In recent years, the damage has become increasingly severe, seriously affecting the development of Fritillaria thunbergii production.

Symptoms: The affected bulbs initially become water-soaked and spread very quickly, and finally the bulbs soft-rot and turn into a mushy "tofu dregs" or "paste" consistency, or become a slimy "snot"-like state, with a distinctive foul odor.

Disease pattern: Bulbs that remain in the field over summer mostly develop the disease during the moldy rainy season (May to June), the dog days (August), and the season of frequent rainstorms. It is especially more likely to occur when the field is low-lying and waterlogged, the soil is heavy and clayey with poor aeration, or the bulbs were not fully spread out to dry before storage and the wounds or insect scars have not healed, or when the sand used for storage is too moist.

Control methods:

(1) The seed retention plot should be chosen as medium sandy soil with high, dry terrain, good drainage, and rich organic matter.

(2) Use 50% carbendazim or 75% chlorothalonil for seed soaking.

(3) Frequently open ditches in the field for drainage and keep the field from becoming waterlogged.

(4) Effectively carry out pest control to prevent the seed coat from being bitten through. When harvesting the bulbs, care should be taken to prevent damaging the seed coat.