Rust of common diseases of canna

Canna

Banana rust is a disease with a high incidence and often occurs in the south, which is mainly threatened by a pathogen called stalk rust in fungi. The damaged plants will have dry leaves and dark brown spots. At the same time, it will also produce some cracked black spots. So what should I do if the canna is infected with rust?

First, symptoms

In the early stage of infection of canna leaves, yellow watery round spots can appear on both sides of the front and back, especially on the back of the leaves. After that, the plaque gradually expanded, with blister-like processes, and the plaque was orange to brown, with a diameter of 2Mel 6 mm. Some varieties had a yellowish-green halo on the edge, and the blister processes of the plaque cracked and scattered orange powdery matter, that is, the summer spores and summer spores of the pathogen. The dark brown powdery matter produced on the disease spot in winter is teliospore pile and teliospore. The seriously damaged diseased leaves are heavily diseased and can be linked into irregular patches, resulting in local necrosis of the leaves.

II. Pathogen

Banana rust (Puccinia thaliae) is caused by fungi of basidiomycetes subphylum, Dipterospora, Puccinia, Puccinidae and Puccinia. The teliospores are yellow-white to orange-yellow, long ovate to elliptic, thick-walled, spiny, born on short peduncles, the size of the teliospores is 20 ~ 25 × 16 ~ 22 microns; the teliospores are long-elliptic to clavate, the top is rounded or slightly flattened, the base is narrow, and the double cells contract slightly at the septum, yellowish to yellow, and the size is 35 ~ 60 × 13 ~ 18 microns.

Third, occurrence regularity

Banana rust began to occur in Guangzhou from March to April. Except for high temperature in summer and cold and dry weather in winter and spring, other cool climate diseases were very serious. The bacteria transmit the summer spores to the healthy leaves through wind blowing and water splashing, and the spores germinate, invade and do harm repeatedly. Sometimes there are many gray-black-brown spots on the diseased leaves, on which there are small black dots, but the yellow rust powder gradually decreases, which is the parasitic fungus of rust (Darluca filum). This fungus and rust fungus compound damage, often aggravate the disease, can make the disease spot expand rapidly, the leaves curl and wither.

IV. Prevention and control methods

1. The introduction or export of breeding materials with disease is strictly prohibited. Diseased leaves should be cut off and disinfected before planting in the disease area.

two。 Remove the diseased leaves and remains of the garden in winter and burn them centrally.

3. In the disease-prone season, spray 1000-1500 times of shark liquid, 65% Fumei zinc 400 times solution or 20% trimethoprim emulsion 2000000 times, once every 7 times every 10 days, pay attention to alternate use, play a role in disease prevention. When the disease is serious, 2000-3000 times liquid of Penicillium can be used for prevention and treatment.

Banana rust

Banana rust is a common disease in cities in southern China, with a high incidence. In the early stage of infection, yellow watery round spots appeared on both sides of the diseased leaves, especially on the back of the leaves. In the later stage, the small round spot is enlarged, and there are orange to brown blister-like processes, with yellowish green halo on the edge, 2mur6mm in diameter, the epidermis of the blister process is ruptured and scattered with orange powder (pile of summer spores of bacteria). After autumn, brown powdery matter is produced on the disease spot (pile of winter spores), and the seriously damaged leaves are covered with disease spots, and can be connected into irregular necrotic areas, and the diseased leaves turn yellow, and finally become brown and dry.

Pathogen and pathogenesis: the pathogen is a kind of stalk rust in fungi. This strain is often parasitized by a kind of rust parasitic bacteria, which causes dense black-brown spots on the original disease spots and produces some small black dots that crack. The two kinds of harm are combined, the condition is aggravated, and the diseased leaves curl and wither. The disease generally occurred in April in Guangzhou. Except for the mild hot and dry weather, the disease was still very serious from October to December when the climate was cool.

Prevention and control measures:

The main results are as follows: 1. To strengthen the sanitary management of the courtyard, combined with garden cleaning in winter, diseased leaves should be removed in time to reduce the spread of infection, and the remains of diseased plants should be thoroughly removed and burned. The diseased leaves were removed in time during the onset period in order to reduce the spread of infection.

2, medicament prevention and cure: at the initial stage of the disease, 0.2mur0.3 Baumedu stone sulfur mixture or 20% verapamil EC 400 times can be used, and the medicine can be sprayed every 10 times every 15 days, which can reduce the harm degree. Spray 65% formazin 400 times or 20% trimethoprim emulsion 2000 mi 3000 times every 7 mi 10 days. Pay attention to alternate use, which can alleviate the disease.

3. The introduction or export of breeding materials with disease is strictly prohibited. Diseased leaves should be cut off and disinfected before planting in the disease area.

How to control banana rust

Banana rust is a common disease in cities in southern China, the incidence rate is very high, the leaves of the damaged plants will gradually turn brown and dry. The root cause is due to a kind of stalk rust in fungi, which is often parasitized by a kind of rust parasites, resulting in dense dark-brown spots on the original disease spots and producing some cracked black spots. The two kinds of harm are combined, the condition is aggravated, and the diseased leaves curl and wither.

The main results are as follows: 1. in the early stage of canna leaf infection, yellow waterlogged round spots can appear on both sides of the front and back, especially on the back of the leaves. After that, the plaque gradually expanded, with blister-like processes, and the plaque was orange to brown, with a diameter of 2Mel 6 mm. Some varieties had a yellowish-green halo on the edge, and the blister processes of the plaque cracked and scattered orange powdery matter, that is, the summer spores and summer spores of the pathogen. The dark brown powdery matter produced on the disease spot in winter is teliospore pile and teliospore. The seriously damaged diseased leaves are heavily diseased and can be linked into irregular patches, resulting in local necrosis of the leaves.

2. The pathogen banana rust (Puccinia thaliae) is caused by fungi of basidiomycetes subphylum, Dipterospora, Puccinia, Puccinidae and Puccinia. The teliospores are yellowish white to orange-yellow, long ovate to elliptic, thick-walled, spiny, born on short peduncles, the size of which is 20mur25 × 16mur22 microns; teliospores are long oval to clavate, the top is rounded or slightly flattened, the base is narrow, the double cells contract slightly at the septum, yellowish to yellow, and the size is 35My60 × 1318 microns.

Third, the occurrence regularity of banana rust began to occur in Guangzhou from March to April. except for high temperature in summer and cold and dry weather in winter and spring, other cool climate diseases were very serious. The bacteria transmit the summer spores to the healthy leaves through wind blowing and water splashing, and the spores germinate, invade and do harm repeatedly. Sometimes there are many gray-black-brown spots on the diseased leaves, on which there are small black dots, but the yellow rust powder gradually decreases, which is the parasitic fungus of rust (Darluca filum). This fungus and rust fungus compound damage, often aggravate the disease, can make the disease spot expand rapidly, the leaves curl and wither.

IV. Prevention and control methods

(1) the introduction or export of breeding materials with disease is strictly prohibited, and the diseased leaves of seedlings in the disease area should be cut off and disinfected before planting.

(2) remove the diseased leaves and remnants of the garden in winter and burn them centrally.

(3) in the disease-prone season, spray 1000-1500 times of shark, 65% Fumei zinc 400 times or 20% trimethoprim emulsion 2000000 times, once every 7 times every 10 days, pay attention to alternate use, play a preventive role in the disease. When the disease is serious, 2000-3000 times liquid of Penicillium can be used for prevention and treatment.