What diseases do flowers need to prevent in autumn

The moderate temperature and humidity and good light in autumn create favorable conditions for the breeding, reproduction and infection of some bacteria, and often cause serious harm to some flowers and plants. The symptoms and control methods of several major diseases are introduced as follows, so that flower growers can prevent and cure them in time.

I. anthrax

1. Symptoms:

The disease mainly occurs in leaves, and can also damage petioles, twigs, stems, buds and petals.

After the damage to the leaves, the initial stage showed a small round pale water-immersed dot, and then gradually expanded, showing a grayish brown, surrounded by a brown edge, slightly raised. Finally, the central part of the lesion faded from gray to white, and the disease was extremely thin, translucent and easy to perforate. There are also some disease first from the tip of the leaf, and then spread to the leaf. The disease spot can often reach 1 ax 3-1 pm 2 of the whole leaf surface, and finally the leaf dies. Some plants are constantly falling off and seriously damaged, often without a single leaf in the whole plant.

When the petiole was damaged, the diseased part became brown, slightly sunken, spread to the main vein, branch vein and even the whole leaf browned, and the disease spot continued to spread downward, from petiolule to total petiole, branchlet, and even stem browned and withered.

In moist conditions, reddish slime is often produced on the disease spot, which is the spore disk produced by bacteria. The damaged plants, the light ones affect the normal growth and development, lose the ornamental value, and the severe ones lead to the death of the whole plant.

Camellia, rose, Milan, white orchid, lily, magnolia, southern bamboo, evergreen, gentleman orchid, cactus, plum blossom, orchid and other flowers are prone to this disease.

2. Prevention and control methods:

Strengthen cultivation management, properly increase phosphorus and potassium fertilizer, avoid partial application of nitrogen fertilizer, watering should not be too much, basin soil should not be too wet, at the same time, ventilation and light transmission should be enhanced and humidity should be reduced. Diseased leaves and petioles should be cut off and burned immediately, and dead plants should be removed in time.

During the onset of the disease, 50% anthrax Fumei wettable powder or 70% methyl topiramate can be sprayed 1000 times, and 75% chlorothalonil can be sprayed once every 10-15 days, 2-3 times continuously, and the control effect can be improved by using agents alternately.

2. Powdery mildew

1. Symptoms:

It mainly harms leaves and can also infect petioles, tender shoots and pedicels, buds, petals and other parts. The damaged part first showed sporadic white powder spots, then gradually expanded and spread, and developed rapidly. Under suitable conditions, the whole leaf could be covered in 7-10 days, and the leaf surface was covered with a layer of white powder, just like defrosting. Damaged leaves, due to the destruction of cell tissue, often make leaf shoots twisted, wilted and ossified, seriously affecting plant growth and development and photosynthetic use. Some can not bloom normally, and some even die as a whole.

Chrysanthemum, impatiens, big leaf yellow poplar, melon leaf chrysanthemum, dahlia, Chinese wolfberry, crape myrtle, honeysuckle, hundred-day grass, rose and other flowers are vulnerable to it.

2. Prevention and control methods:

Strengthen cultivation management, poor ventilation, muggy and so on. Powdery mildew is serious in high temperature and humid environment. Therefore, the flowerpot should be placed in a place with better ventilation and light transmission conditions. Pay attention to the application of phosphorus and potassium fertilizer, avoid partial application of nitrogen fertilizer, watering should not be excessive. And in time to remove diseased leaves, cut off diseased branches, diseased buds. Remove the diseased plant, burn it centrally, and reduce the re-infection of the pathogen.

At the beginning of the disease, you can spray the same amount of Bordeaux liquid, and after the onset of the disease, you can spray 1000 times of the wettable powder or 1000 times of the methyl topiramate. In severe cases, spray once every 10 days or so for 2-3 times in a row.