A common disease of Canna plantain

Canna

Canna bract disease is a serious disease mainly distributed in southern China. If it is not controlled, it will be a great loss of wealth for farmers. Therefore, understanding the characteristics and incidence of this disease will be more convenient for farmers to cultivate and control.

I. Characteristics of harm

Larvae often roll leaves into a bud, eating leaves, serious when the bracts are numerous, resulting in incomplete scorched leaves, affecting plant photosynthesis.

II. Shape characteristics of banana bract insect

Female adults are 28-31 mm long and have wing spans of 60-80 mm; male adults are 24-27 mm long and have wing spans of 55-70 mm. Body blackish brown, head and thorax densely covered with taupe scales. Antennas hammer-shaped, black-brown, nearly swollen mostly white. Both wings are black and the hair is white. Front wing front edge near the base is grayish yellow scale hair; wing center has two yellow square large spots, near the outer edge has a square small spot.

The eggs are red, steamed bun shaped, 2 mm in transverse diameter. The egg shell surface has radial white longitudinal striations.

The old larva is 50-64 mm long and has white wax powder on its body surface. The head is triangular and black. Each section of the body has transverse wrinkles and dense fine hairs.

The pupa is slightly cylindrical, 35-41 mm long, yellowish white, and whitewashed. Muzzle up to or beyond the end of the abdomen, after the muzzle does not separate from the pupal body. Abdominal buttock thorn end many hook thorn.

III. Rules of occurrence

In Fujian Province, it overwinters in leaf bracts as mature larvae, and adults appear in the middle and late March of next year. 1-3 The adults emerge from mid-June to early October, and the larvae enter the overwintering stage in November. In summer and autumn, egg stage lasts about 5 days. The larva stage lasts 25 days and the pupa stage 10 days. Adults prefer cool environment, in the sunny morning and evening activities, cloudy activities throughout the day, generally scattered eggs on the host leaves, tender stems, petioles. Larvae hatch after climbing to leaf edge bite leaves into a notch, and then spin silk sticky leaves roll, into a cylindrical bract. The larvae in the bract lean out of the bract in the morning and evening to feed on nearby leaves. 8-9 The month is the peak period of harm.

IV. Control methods

1. During the larval period, the insect bud can be removed artificially and the larvae can be killed.

2. Protection and utilization of natural enemies.

3. Late autumn and early winter, clean up sick leaves, dead leaves, eliminate overwintering larvae.

Common pests of Canna plantain and their control methods

Canna

Canna is a kind of plant with low requirements for living environment. It is easy to breed, easy to reproduce and has long flowering period. It is a common greening and environmental protection plant on the roadside. It is a plant that beautifies the environment in many courtyards. Under normal circumstances, as long as there is sufficient sunlight and sufficient water, it can be fed anywhere. But no matter where the plantain grows, it can't avoid being disturbed by pests. So what are the common pest diseases of plantain?

1. mosaic disease

symptoms

The leaves of susceptible plants showed mosaic or yellow and green flower spots, petals became smaller and formed variegated, and when the disease was serious, the leaves became abnormal, rolled in, and the patches died.

control methods

1. Because canna is sub-root propagation, easy to make the virus passed from year to year, so in reproduction. Virus-free mother plants should be used as propagation materials. Discovered diseased plants are immediately removed and destroyed to reduce the source of infection.

2. The disease is transmitted by aphids, and insecticides are used to control aphids and reduce vectors. 40% omethoate 2000 times solution, or 50% malathion, 20% diazinon, 70% promethion 1000 times solution spray.

II. Whiteflies

Any of various small white powdery waxy insects of the family Aleuropidae, usually of the order Homoptera, that swarm to damage plants. It is easy to occur when the cultivation ventilation is poor. It often harms the tender leaves and flower buds of Canna. When it is harmed, it inserts its piercing mouthparts from the back of the leaves to absorb the juice from the plant tissues, causing the leaves to turn yellow, and often excretes a large amount of honeydew at the wound site, inducing coal pollution, mold and other diseases. Because of its strong reproductive ability, whitefly can reproduce 9~10 generations in a year in greenhouse, and can form a large number in a short time.

control methods

Because whitefly adult body has white waxy powder, bring difficulty to control, so control should be timely, drug control to nymph stage is better, commonly used 2.5% deltamethrin, or 10% permethrin, or 20% metributin diluted 2000 times solution, the effect is better; also can use 40% dimethoate, or 80% dichlorvos, or 50% marathon emulsion every 5~6 days once, to spray 2~3 times continuously. Can also use pests such as natural enemies aphid, also has a certain effect.

III. Bud rot

symptoms

Before canna leaves open and bloom, bud rot bacteria invade through stomata of young leaves and flower buds. When canna leaves open, many small spots appear on the leaves and gradually expand, connecting with each other along the veins to form large spots, sometimes the spots form stripes. The spots begin to appear greyish white and soon turn black. Infected flower buds blackened and died before flowering. Lesions can spread downward along petioles, causing young stems and buds to die. When the old leaves are injured, the disease spots expand slowly, irregularly, yellow, and the edges are water-stained.

control methods

1. Healthy rhizomes are selected as propagation materials. The rhizomes suspected of carrying bacteria are soaked in 500~1000 times solution of streptomycin for 30 minutes before planting, which can not only prevent diseases, but also promote the growth of buds and branches.

2. It should be planted in sunny, fertile and humid areas with good drainage to avoid over-dense planting.

3. At the early stage of plant disease, Bordeaux mixture (1:1:200) or 77% KCD WP 500 times solution, 14% complex ammonia copper solution 400 times solution, etc. were sprayed.

4. Remove seriously diseased plants and sick bodies at any time and burn them.

Canna

IV. Banana bract insect

The adults lay eggs on the leaves, tender stems and petioles of Canna plantain, and after hatching, they climb to the leaf edge to bite the leaves, and spin silk to stick the leaves into curly bracts. In the morning and evening, they climb out of the bracts to bite the nearby leaves. In severe cases, there are numerous bracts and incomplete leaves on the plants, which affect the growth and viewing effect.

control methods

Remove the bracts and kill the larvae in time;

Before the larvae hatch and form leaf bracts, kill the larvae with 90% trichlorfon 1000 times solution, or spray them with 1000 times solution of chlorpromazine in the morning or evening.

V. Little cutworm

Small cutworm also known as ground silkworm, black soil silkworm, etc., moth larvae, yellow brown to dark brown body, back line obvious, rough skin, 1 year can reproduce 4~5 generations. Its adults are medium-sized moths, with brown front wings, reniform striations and black wedge spots, which are obvious. When it is damaged, wormholes will be seen on the leaves of plants, and serious flower buds will be damaged, resulting in the production of flowerless plants.

control methods

In the cultivation management process, remove surrounding weeds and keep the environment clean. Available black light or sweet and sour trap adults, with a pile of grass or bait trap larvae. Such as 90% crystal trichlorfon and wheat bran or bean cake crumbs 1:50 water stir with the right amount, in the evening when scattered in the rhizosphere trap. Can also be poured on the rhizosphere or seedbed 50% phoxim, or 40% dimethoate, or 80% dichlorvos 1000 times liquid poison black cutworm.

Whether breeding animals or plants, farmers are most worried about diseases. Generally, common diseases can be treated as long as the cause is found and drugs are found. However, infectious diseases are not controlled by farmers, so prevention is critical.

Control of main diseases and insect pests of Canna grandiflora

Common pests and diseases of large flower canna include:

① Mosaic disease. When Canna grandiflora was infected with mosaic virus, chlorosis and intermittent yellow stripes appeared along the veins to the leaf margin, and extended to most of the leaves in the later stage, even the whole leaves appeared yellow, wrinkled and curly, and the petals appeared broken color stripes when flowering.

Control methods:

a. Virus-free, robust rootstock material should be selected for reproduction, and aphids, the vector of the disease, should be controlled throughout the growth period;

b. Discovered diseased plants should be removed and destroyed in time.

2. Banana bud insect. The adults lay eggs on the leaves, tender stems and petioles of Canna grandiflora. After hatching, the larvae climb to the edge of the leaves to bite the leaves, and spin silk to stick the leaves into curly bracts. They climb out of the bracts in the morning and evening to bite the nearby leaves. In severe cases, there are numerous bracts and incomplete leaves on the plants, which affect the growth and viewing effect.

Control methods:

a. Remove bracts and kill larvae in time;

b. Kill larvae with 90% trichlorfon 1000 times or spray them with chlorpromazine 1000 times in the morning or evening before they hatch and form bracts.