Harm and Control Methods of Angelica Rust

The pathogen is Puccinia angelicae (P. angelicae). Urediniospores are oval to oblong-elliptical, yellowish-brown, (25-42) micrometers x (22-30) micrometers, with small spines on the surface and 3 germ pores. Teliospores are elliptical to club-shaped, chestnut-brown, (32-49) x (17-26) micrometers, with rounded ends and slightly constricted at the septum; the stalk is colorless and deciduous. Single-spored teliospores sometimes occur.

1. Damage symptoms: It damages leaves, and also damages petioles and fruit stalks. Uredinial pustules are scattered or clustered on the underside of leaves, exposed, brown. Telial pustules adhere to both sides of the leaves, exposed, black.

2. Disease development pattern: The pathogen overwinters as teliospores in latent form on diseased fallen branches and leaves and on the rhizomes of field plants. In the following spring, spermogonia form, and around them uredinial pustules and urediniospores are produced, infecting newly sprouted leaves. Urediniospores are spread by wind and rain and by seedlings, and can cause repeated infections multiple times. Under conditions of 18-22°C and 75-80% relative humidity, it spreads rapidly, and the disease is severe from July to August.

3. Control measures

(1) After harvest, collect and burn diseased fallen leaves and plant residues to reduce overwintering sources of inoculum.

(2) After the disease occurs, promptly dig out and remove diseased plants, and spray 1:1:200 Bordeaux mixture once every 7-10 days, for 2-3 consecutive sprays.

(3) In the early stage of the disease, spray 0.2 degree Baumé lime sulfur mixture or 97% dinocap 400-fold solution. Once every 7 days, for 2-3 consecutive sprays.

(4) Strengthen field management to improve the disease resistance of the plants.