Report on flower diseases and insect pests in September and preservation methods of edible fungi

When it comes to White Dew, the weather in most parts of China is gradually getting cooler, but in the Autumn Equinox, there is a balance between day and night, which is the beginning of autumn in the northern hemisphere. Some flower species with summer dormancy and semi-dormancy habits will resume their growth with the decrease of air temperature, which is another important growing season for all kinds of flowers in a year.

Due to high temperature and low air humidity this month, some leaf-eating and piercing pests are still likely to occur, such as diamondback moth, pocket moth, red spider, shellfish, yellow poplar silk borer, silkworm moth, longicorn beetle, wood lice, net bugs and so on. Some diseases will continue to occur, such as Albizia wilt, powdery mildew, sweet-scented osmanthus brown spot, crape myrtle, cherry brown spot perforation, sunburn and so on. Red spot, bacterial perforation and glue disease will also occur seriously.

Main diseases occurred in September and their control countermeasures

Cherry blossom brown spot perforation

The main damage to peach, peach, plum blossom, red leaf plum, elm leaf plum and other ornamental flowers and trees, resulting in dense holes in the plant leaves, causing a large number of diseased leaves to fall off, seriously affecting the normal growth of the plant.

The disease occurs all over the country, and its pathogens are Cercospora, Trichospora, Trichosporium. It is mainly harmful to growing leaves and young branches. needle-sized purple-brown dots appear at the initial stage of the diseased leaves, which are enlarged into round spots, with a diameter of about 1Mel 4mm, purple to reddish purple on the edge, brown in the middle and slightly wheeled. There are fluffy dots on the plaque. In the later stage, the disease spot fell off and became a perforation spot. The pathogen overwintered in the shoots and fallen leaves, and the disease occurred in the lower leaves of the plant in June, and the peak period was from August to September. A large number of diseased leaves fell off from late August to late September, and only a small amount of leaves remained on the shoots. The disease is easy to occur under the conditions of dense planting, poor ventilation and weak branches, and the disease is serious.

Prevention and control countermeasures

1. Clear the fallen leaves early in autumn and winter and burn them centrally. Water them in time during the growing season.

2. Trim the inner bore branches, disease and insect branches, thin branches and dead branches regularly to ensure that the crown is well penetrated.

3. Before germination in spring, disinfect the trees with 2murl and Baumedo stone sulphur.

4. in the early stage of the disease, the plants were sprayed with 50% carbendazim wettable powder or 1000 times methyl topiramate wettable powder, once every semimonthly for 3 consecutive times, which had a good control effect.

Arbuscular disease

The main types of arbuscular disease in ornamental flowers and trees are: crape myrtle, rose, Yingshanhong, oleander, elm, bamboo, lobular magnolia, Hawthorn, clove, Catharanthus roseus, banyan and so on.

The main causes of arbuscular disease are phytoplasma and fungi. The former is a kind of plant pathogens that can not be cultured artificially. It has no cell wall and is surrounded by three layers of unit membranes. It parasites exclusively on the phloem sieve tube system of plants, causing clumps of branches, metamorphosis of floral organs, leaf yellowing, tree necrosis, growth decline and death. From the process of symptom development, first of all, the top growth of the branch was inhibited, which stimulated the growth of the lateral bud was also inhibited soon, and made its own lateral bud develop into branchlets in advance again. As a result of such repeated results, the branches of the killed flowers and trees increased their branchlets and volume with the passage of time, and the tufted branches withered that year or died year by year. From the morphology and anatomy of the branches and leaves, the main branches in the branches are not obvious, the branchlets are thin and internodes are short, the parenchyma is well developed and the mechanical tissue is underdeveloped, so it is fragile and easy to break; the leaves on the branches are small and yellowing, and the differentiation of internal tissue and sponge tissue is not obvious. The diseased branch can bear small fruit or abnormal fruit at the beginning, but then it becomes unfruitful or even no longer blossoms. Witches' broom disease caused by phytoplankton is destructive. The disease starts from individual branches and gradually spreads to the whole plant. Arbuscular disease caused by phytoplasma is mainly transmitted by insects in nature, and under cultivation conditions, it is transmitted by grafting, cutting, ramet and other reproductive materials.

Prevention and control countermeasures

The main results are as follows: 1. When propagating flowers and trees by cutting, grafting, splitting, striping and other methods, healthy mother plants must be selected.

2. When a small amount of arbuscular branches are found on potted or ground planted crape myrtle, Yingshanhong, hammer elm, rose, oleander, clove and Catharanthus roseus, the arbuscular branches should be cut and burned as soon as possible, and the pruning knives should be strictly disinfected at the same time.

3. From spring, 10% imidacloprid wettable powder (2000 times) or 40% omethoate EC (1500 times) should be sprayed regularly to kill aphids, thrips, bugs, scale insects and other stinging pests, and to eliminate transmission media.

4. Injection of tetracycline drugs into the diseased plants has a better therapeutic effect.

Albizia wilt

Albizia wilt is a devastating disease that can be prevalent. The disease can occur from immature seedlings to big trees, and when the disease is serious, a large number of trees wither and die, which is common in Beijing, Nanjing, Jinan, Hefei and other places in China. After infected with Fusarium wilt, the leaves wilted, drooped, dried and shrunk, then the leaves fell off and the branches withered. There are plenty of one or two branches or several branches to show symptoms, some half of the branches die, and in serious cases, the whole plant dies. A whole circle of discoloration ring appeared on the cross section of the trunk and branches, and the root cortex of the diseased plant turned brown and rotted. In summer, the trunk becomes rough, or the trunk secretes black liquid to rest, and the lenticels are swollen. Under wet conditions, cinnamon to white powdery mildew layer can be produced in the lenticels of diseased plants.

The pathogen remains in the soil, diseased tissue and seeds, and invades directly from the underground root or through the wound, resulting in plant death. In the nursery, the roots of some diseased seedlings are intact, but the cut ends become withered, and after longitudinal cutting, the interior has turned brown. Bacteria can also be isolated from brown sapwood, and cutting is one of the main ways for pathogens to invade. The disease is a systematic infectious disease, which can occur throughout the growing season, with symptoms in May, the peak period from June to August, and the disease can continue until October. High temperature and humidity are conducive to pathogen proliferation and infection, rainstorm and irrigation are conducive to pathogen transmission, but water shortage and drought will also promote the occurrence of diseases.

Prevention and control countermeasures

The disease has a wide source of bacteria, a long period of infection, spread through the soil, but also a systemic disease, which is difficult to detect in the early stage, and difficult to save once the symptoms appear, so it is necessary to give priority to prevention and comprehensive control.

1. Choose a suitable planting site. Acacia grows better in loose soil, solid soil on the street and poor permeability, so it is best not to use it as a street tree, but to plant it in the green belt on both sides of the road.

2. Strengthen tending and management, such as loosening the soil regularly, increasing soil permeability and paying attention to drought prevention and drainage. Prune as little as possible, and the wound should be protected after pruning. Eliminate seriously diseased plants to reduce the source of infection

3, pay attention to chemical control, before there are no symptoms in the growing season, open holes to irrigate internal absorbent agents, such as 50% topiramate 500 times solution, 40% carbendazim glue suspension 800 times solution and so on. When transplanting, 1% copper sulfate solution is dipped in the root, and the wound on the branch is coated with a protective agent to prevent bacterial infection.

Powdery mildew

It continued to occur in various parts of the country in September, harming many kinds of flowers, such as crape myrtle, ten meritorious works, heather, big leaf yellow poplar, rose, hibiscus, a string of red, calendula, impatiens, melon leaf chrysanthemum, purple jasmine, peony, peony and so on.

The pathogen is harmful to leaves, tender shoots and inflorescences, and the damaged parts produce a layer of white powdery mildew, which then turns gray-white, which often causes leaves to wrinkle, fade, can not expand normally, branches bend, abnormal atrophy, inflorescences twist and buds lose color, which seriously affects the normal growth and flowering of flowers and trees. The pathogen overwintered as mycelia lurking in the dormant buds of infected plants. From late March to early April in the coming year, with the growth of buds, the mycelia began to expand and spread when the climate was suitable. And the formation of conidia spread to the tender shoots, new leaves and inflorescences of new host plants by wind and rain, and the conidia could be re-infected many times. Under the condition of poor ventilation and light transmission and planting too dense code, the disease is particularly serious. In general, the disease begins in spring every year, and the peak is from June to September, and the disease gradually alleviates after late September.

Prevention and control countermeasures

1. Control the density, increase ventilation and light transmission, increase the application of phosphorus and potassium fertilizer, and improve the disease resistance of the plant.

2. For the species of flowers and trees that are prone to the disease, or if powdery mildew has occurred nearby, during the germination and shoot-shooting period after each pruning, the new shoots and tender leaves are sprayed with 1 Bomedo stone-sulfur mixture or 27% high-fat film 500 times solution, once every 10 days, 23 times in a row.

3. Cut off the newly infected shoots in time and burn them centrally.

4. At the initial stage of the disease, 1000 times of 15% triadimefon wettable powder or 2500 times of triadimefon wettable powder were sprayed alternately.

Mosaic disease

Due to the invasion of virus, some symptoms such as yellow and green alternation and deformity appear in the leaves and shoots of flowers and trees. Virus is a kind of acellular structure organism, after invading the flower plant, it sometimes shows yellow-green mottle or stripes on the leaves, such as a string of red and tea plum "mosaic". On the surface, it is somewhat similar to the yellowing caused by hypoxia, but it is not difficult to find that the chlorosis caused by mosaic disease is uneven. It is a kind of yellow-green color block, which is distributed in blocks or strips on the leaves. Not only the distribution of the diseased leaves on the plant is irregular, but also the distribution of yellow disease spots in the leaves is irregular, which is often characterized by leaf shrinkage and non-luster, smaller or narrower leaves. There is little necrosis and the whole plant grows poorly. It starts with a small number of plants, and gradually increases from light to heavy, and is obviously contagious. once the virus enters the flower plant, it "replicates" and propagates in large quantities, so it is difficult to kill or eliminate it, and it will carry the virus for life. It's a very annoying and troublesome disease. Different from fungal diseases, it is not fixed in a certain part of the plant after entering the body, but reaches every part of the plant through the circulation of plant juice; the main damage to the plant is not to kill the tissue, but to make the good characters of the plant degenerate step by step, and then the resistance decreases and weakens, and it is easy to die caused by other diseases and pests.

Flower species prone to mosaic disease are: gladiolus, canna, lily, red, tulip, orchid, geranium, cyclamen, dahlia, cycad, camellia, tea plum, carnation and so on. Piercing mouthparts insects are the most important viral media in nature, such as aphids, shell insects, bugs, leafhoppers and so on. When it sucks the juice on the diseased plant, it also sucks in some virus, and then injects the virus into the healthy flower plant by sucking the juice of other plants. In addition, scions, cuttings, rhizomes and bulbs may carry the virus, and coring, pruning and other operations may also spread the virus.

Prevention and control countermeasures

1. Kill the pests of piercing and sucking mouthparts in time, prohibit the propagation of poisonous branches or bulbs, remove the diseased plants and burn them as soon as possible, and strictly disinfect the tools used in grafting and cutting.

2. The plants with mild disease can be controlled with pesticides such as antiviral agent No. 1, Shiduqing, virus A, Zhanshengling, Virobike and so on.

In September, the more serious flower and plant diseases include mildew, algal spot, black spot, glue, sunburn, leaf swelling and so on, which should be paid more attention and timely and effective comprehensive control measures should be taken.

Main insect pests occurred in September and their control countermeasures

Woolly aphid, APHIS gossypii

It occurs all over the country, mainly harming bonsai plants and greening trees of elm trees such as hammer elm, thorn elm, white elm, drunken Weng elm, Langya elm and so on. Because it is a parasitic insect, it also harms many kinds of ornamental plants of Gramineae. The overwintering host is mainly elm, and the alternate host is mainly Gramineae, which occurs more than 10 generations a year, overwintering eggs in bark cracks such as hammer elm and drunken elm, and overwintering eggs hatch in April of the following year, harming leaves and forming galls. After developing into adults, the migratory aphids were produced and migrated to the roots of Gramineae plants from May to early June. The aphids developed into adults from September to October and produced sexual aphids on elm trees. After mating, they spawned in the sunny and leeward cracks in the trunk of more than 4-year-old elm trees and overwintered with eggs. At the turn of spring and summer, sparse or dense granular galls are formed on the leaves of elm, which not only affect the ornamental, but also endanger the normal growth of the plant.

Prevention and control countermeasures

In the display of nut elm pile bonsai, or near the seedlings where elm seedlings are cultivated, especially in May-June, it is the inter-host that completely removes Gramineae weeds and autumn four-veined woolly aphid. In the overwintering egg hatching stage, after the aphids moved back to the elm, they were sprayed with 2000 times of imidacloprid wettable powder. It can also be sprayed on the trunk of elm stump or elm in autumn and winter, which can effectively kill the overwintering eggs. If a small amount of light red autumn four-vein aphid gall appears on the bonsai plant, it can be removed as soon as possible.

Spodoptera litura Linnaeus

It is mainly harmful to flowers and trees such as gardenia, big-leaf yellow poplar and coffee, and the young larvae gnaw on the young shoots of tender leaves, resulting in more gaps or holes in the middle and upper part of the crown of flowers and trees such as potted or ground-planted gardenia, thus reducing their ornamental value; when a large number of larvae occur, the whole plant or pieces of gardenia leaves can be eaten up. It is the most important leaf-eating pest to damage gardenia.

In the Yangtze River basin, the kidney overwintered in the soil layer of 5 cm deep, and emerged in late April of the following year. The adults of the second and fourth generations appeared in June, August and October, respectively. The adult is about 10 months after emergence. Adults mate and lay eggs about 10 hours after Eclosion. Eggs are mostly laid on concealed young leaves, new shoots, buds and petals, laying 2 eggs in each place, female adults can lay about 200 eggs, and the egg period is 3 mi for 5 days. The newly hatched larvae first ate the eggshell, then ate the tender leaves, and the food intake increased after the 4th instar, and the larval stage was about 45 days.

Prevention and control countermeasures

1. During the period of larval occurrence, the host flowers and trees such as Gardenia jasminoides are often checked and the larvae are artificially killed.

2. Ploughing the soil around the flowers and trees in late autumn and early winter to kill the overwintering pupae

3. If it occurs in a large area, the plant can be sprayed with 90% trichlorfon crystal 800 times liquid, which can quickly kill its larvae.

Bombyx mori moth

Chinese tallow silkworm moth, also known as Sapium sebiferum, is distributed in Northeast China, Shandong, Anwei, Jiangsu, Zhejiang, Shanghai, Jiangxi, Sichuan and other provinces, mainly harming camphor, Chinese tallow, Toona sinensis, du Ying, Platycladus orientalis, Maple Poplar, Michelia mollissima, holly, Albizia, citrus, Robinia pseudoacacia, paulownia and other ornamental plants. The insect has two generations a year, overwintering as pupa in cocoon, the first generation larvae hatch in late May, the damage period of the second generation larvae is from September to late October, the newly hatched larvae are clustered and dispersed after the 4th instar, the mature larvae form cocoons on trees, and the overwintering generations often form cocoons on miscellaneous shrubs.

Prevention and control countermeasures

At the end of August, making use of the phototaxis of adults, black light or frequency vibrating lights were hung near the seedlings of camphor trees to trap and kill adults. In the stage of low instar larvae, using its gregariousness, for low camphor seedlings, the dense leaves of the larvae can be removed manually and killed centrally; or in the stage of larval damage, 90% trichlorfon crystal 800x liquid or 2.5% fenvalerate 1500 times liquid can be sprayed; cocoons formed on miscellaneous shrubs can be cut off and burned in time, which can lead to a large number of insect pests in the coming year.

Short-forehead negative locust

Because the male adult copulates on the back of the female, it is known as the "negative locust". Mainly distributed in the Yangtze River basin, harming a bunch of red, pansy, rose, gardenia, chrysanthemum, tail and other flower species, gnawing leaves and petals, resulting in imperfections and holes, reducing the ornamental value of flowers. There are two generations a year in the Yangtze River basin, overwintering with eggs in the soil. The second generation nymphs began to hatch from late June to mid-late August, Eclosion from mid-August to mid-late October, and spawning from late November to mid-December. The adults and larvae mostly feed on the branches and leaves and like to do harm in clusters, and the eggs are laid in blocks in the soil with few weeds in the wasteland and wrapped in colloid.

Prevention and control countermeasures

1. Remove the weeds around the flowers and plants, plough the nursery in late autumn and early winter, and kill the eggs.

2. During the period of larval damage, manual hunting in the morning can be used as a high-quality protein food for poultry.

3. When it occurs on a large scale. It can be sprayed with 1500 times of 90% trichlorfon crystal or 75% insecticidal double EC.

Stinging moths

The hot and dry environment in September is a period of crazy damage to the larvae of stinging moths. The second generation larvae of Spodoptera litura damaged the leaves of cherry blossoms, crape myrtle, sweet-scented osmanthus, white magnolia, pumpkin elm, green peach, plum blossom, camphor, du ying and other flowers and trees from mid-August to late September, while the second generation larvae of Spodoptera litura reached its peak from mid-August to September, mainly harming the leaves and shoots of cherry blossoms, rose, begonia, plum blossoms, white wax, holly, Chinese tallow, bauhinia, elm and other ornamental plants. From late August to September, the second generation larvae of mulberry brown diamondback moth damaged the leaves of camphor, French holly, Sapium sebiferum, Sapium sebiferum, ginkgo biloba, seven-leaf tree, Eucommia ulmoides, green peach, cherry blossom and other flowers and trees. The second generation larvae of Plutella xylostella and Spodoptera litura damaged the leaves of begonia, plum blossom, bauhinia, crape myrtle, rose, sweet-scented osmanthus, pomegranate, peony and other flowers and trees from August to mid-September. When the larva density is high, the leaves and shoots of the whole plant can be eaten up.

Prevention and control countermeasures

1. Use black light or frequency vibrator to trap and kill adults.

2. For serious nursery or garden green space, the larvae can be sprayed with 2000 times of 25% trichlorfon crystal or 1000 times of omethoate EC at the stage of newly hatched larvae.

In March and September, there are other pests that often occur in September, such as bag moth, red spider, Sik Wei leaf wasp, elm three-leaf wasp, net bugs, wax cicadas, shell insects and so on.