Harm and control of Angelica rust

The pathogen is Angelica sinensis stalk rust (P.angelicae). The summer spores are ovate to long oval, yellowish brown, (25Mu42) microns × (22Mel 30) microns, with small spines on the surface and 3 germination pores. Teliospores elliptic to clavate, chestnut brown, (32 / 49) × (17 / 26) microns, round at both ends, slightly constricted at septum; stalk colorless and detachable. Monospore teliospores sometimes occur.

1. Harmful symptoms: damage to leaves, petioles and fruit stalks. Summer spores scattered or grouped on abaxial surface of leaves, bare, brown. Teliospore pile attached to both sides of leaves, bare, black.

2. the law of disease: the pathogen overwintered with winter spores on the diseased residual branches and leaves and on the roots and stems of plants in the field. The sexual spore organ will be formed in the spring of the following year, and a pile of summer spores and summer spores will be produced around it, infecting the newly produced leaves. Summer spores are transmitted by wind, rain and seedlings, and can be repeatedly infected. It spread rapidly under the condition of temperature 18 ℃ 22 min and relative humidity 75 mi 80%, and the disease was serious from July to August.

3. prevention and control measures

After ① harvest, the residual plants and diseased leaves were cleaned up and burned to reduce the source of overwintering bacteria.

After the onset of ②, the diseased plants were dug up in time, and the diseased plants were sprayed with Bordeaux solution of 1, 1 and 200 Bordeaux every 10 days, 3 times in a row.

At the initial stage of the onset of ③, Baumei 0.2 degree stone sulfur mixture or 97% dipyridamole 400x solution was sprayed. Once every 7 days, spray 2muri for 3 times.

④ strengthens field management and improves plant disease resistance.