How to prevent and control pests and diseases of Photinia × fraseri? Three major methods explained in detail

Photinia × fraseri has relatively strong resistance, and no devastating pests or diseases have been found. Common pests and diseases of Photinia × fraseri include damping-off, seedling blight, leaf spot, anthracnose, gray mold, leaf spot, or damage by scale insects. These infectious diseases often cause large-scale death of Photinia × fraseri in a short period, bringing serious losses to seedling growers. Huinong Academy, citing the views of seedling experts, introduces several comprehensive prevention and control measures for the reference of seedling grower friends when needed.

I. Chemical treatment

Starting from the seedling stage of Photinia × fraseri, every 7-10 days spray 50-75 kg of 0.5-1% Bordeaux mixture per mu of Photinia × fraseri seedbed onto the young Photinia × fraseri seedlings, so that a protective film forms on the outside of the young Photinia × fraseri seedlings to prevent pathogen invasion. At the same time, fertilization must be well controlled; fertilizer should be mainly farmyard manure, supplemented by chemical fertilizer. Garbage fertilizer, compost, and barnyard manure may carry pathogens and should be piled for fermentation and decomposition before use. After disease occurs, promptly remove diseased Photinia × fraseri seedlings, spread lime powder around the holes of diseased Photinia × fraseri seedlings to prevent spread, and apply pesticide once every 10-15 days. Per mu, 100 kg of 500-800 times dilution of Dexon, or 100 kg of 300-800 times dilution of 65% zineb may be sprayed, or 150 kg of 1:100 methyl arsenic sulfide medicinal soil, or an appropriate amount of 8:2 plant ash and lime powder mixture may be spread on the Photinia × fraseri seedbed for treatment. Copper-ammonium mixture may also be sprayed for treatment.

Gray mold can be prevented by spraying 1000 times dilution of 50% carbendazim, and during the disease period, 800 times dilution of 50% zineb can be sprayed for control. Leaf spot can be controlled with 300-400 times dilution of 60% carbendazim or 300-400 times dilution of thiophanate. Scale insects can be controlled by spraying 200 times dilution of dimethoate emulsion or 800-1000 times dilution spray. Control of cutworms should be carried out before planting; the soil should be deeply plowed appropriately, and phosphorus-containing insecticides such as Tuchong Bisha should be spread. If cutworm damage occurs after planting, remedial treatment must be carried out promptly; otherwise, once it spreads, the damage will be great, especially to Photinia × fraseri at the seedling stage, possibly causing large-scale death.

II. Seed disinfection

Before sowing, seeds should be carefully selected, and diseased and weak seeds should be eliminated. During sowing, seeds should be treated with chemicals. They can be soaked in 0.3-0.5% potassium permanganate solution for half an hour to 1 hour, or soaked in 50°C warm water for 24 hours. Then take out the sunken seeds and soak them in 0.2% formalin solution for 30 minutes, then take them out and keep them covered for 2 hours. They can also be soaked in 0.5-1% copper sulfate solution for 1-2 hours, then the seeds are taken out and rinsed with clean water to wash off the chemical solution, dried in the shade, and sown at the proper time. Pay attention to depth when sowing; the covering soil should not be too thick, so that the seeds can germinate and emerge.

III. Choose a good nursery site

A light clay loam or sandy loam with good water sources and relatively high terrain should be selected as the nursery site, and a crop rotation system should be maintained, not continuously cultivating the same kind of Photinia × fraseri on the same nursery site.

When raising seedlings, the nursery soil should be disinfected in advance. The main methods are the following 4:

① Formalin disinfection: For each square meter of nursery, use 50 ml of formalin added to 10 kg of water and spray evenly on the ground surface, then cover with plastic film or straw bags, keep sealed for about 10 days, uncover the covering to let the gas volatilize, and sow after two days.

② Carbendazim disinfection: Use 50% wettable powder, mixing 1.5 grams per square meter. It can also be prepared into medicinal soil at a ratio of 1:20 and spread on the seedbed, all of which can effectively prevent and control seedling-stage diseases.

③ Quintozene disinfection: For each square meter of nursery land, use 4 grams of 75% quintozene and 5 grams of zineb, mix them, then mix evenly with 12 kg of fine soil. When sowing, place it underneath and cover on top. It has special effects on anthracnose, seedling blight, damping-off, sclerotinia, and other diseases.

④ Ferrous sulfate disinfection: Treat the soil with 3% ferrous sulfate solution, using 0.5 kg of medicinal solution per square meter. It can control seedling blight of coniferous flowers and trees, leaf-curling disease of peach and plum, and also control chlorosis caused by iron deficiency in flowers. The nursery land is best deeply plowed in winter, and shallowly plowed once when sowing the next year.

Latest pest and disease control list

            Lace bug: Mainly harms plants such as firethorn, cherry blossom, and rhododendron. This year lace bugs also caused damage on London plane leaves, and some London plane trees were severely damaged. The front of the damaged leaves changed color obviously, and on the back of the leaves adult lace bugs, nymphs, and large amounts of secretions were clearly seen, directly affecting plant growth. It can be sprayed with 1:1000 dilution of Dachongling.
Longhorn beetles and other trunk-boring pests: Recently, a small number of adult longhorn beetles are still active. The more obviously damaged plants include London plane, Chinese scholartree, and redleaf plum. At present, many boreholes are found on damaged trunks, and fresh insect frass and other materials are continuously discharged from the holes. Manual digging and inserting poison sticks and other measures should be organized as soon as possible to kill the larvae. For adults, 300 times dilution of Green Weilei can be sprayed. Prevent once more after 10 days.
Powdery mildew: Mainly occurs on shrubs such as large-leaf boxwood and Mahonia. Because since the beginning of summer this year, high-temperature and high-humidity climate conditions have favored the spread of this disease, measures should be taken promptly for prevention and control. Control method: remove infected leaves by pruning, handle them centrally, and spray 1:800 dilution of triadimefon powder continuously 2 times, with an interval of 10 days.
Shrub leaf withering: In every high-temperature season, affected by weather and various other reasons, leaf withering symptoms easily appear on golden-leaf privet and large-leaf boxwood. Entering August is the peak period of this symptom, so special attention should be paid to strengthening watering, and reducing pruning frequency during high temperatures. If pruning is truly needed, it is recommended to use large scissors for light pruning, and immediately after pruning spray 1:1000 dilution of carbendazim or thiophanate for prevention and control.
Tea bagworm: Commonly known as small bagworm, it harms camphor, firethorn, redleaf plum, photinia, and others. At this stage, it is exactly the occurrence period of the first-generation larvae of this insect, and larval damage has already been seen on plants such as photinia and camphor, so attention should be paid to inspection and control. For control chemicals, 1:2000 dilution of beta-cypermethrin can be sprayed. Manual removal of insect bags can also be adopted for elimination.
Tortricid moth: Entering August, on shrubs such as golden-leaf privet, large-leaf boxwood, and firethorn, tortricid larvae form nests and cause damage. Combined with pruning, cut off the insect nests, handle them centrally, and spray 1:1000 dilution of trichlorfon or 1:1500 dilution of Kuaishaling for control.
Bischofia caterpillar moth: Recently it is exactly the peak emergence period of the second-generation adults, and the number is relatively large. In addition, the recent temperature is suitable. According to forecasting, in early August the third-generation larvae will appear and feed and cause damage. Control should be carried out around August 15, and once more after 7 days. For control chemicals, 1:1000 dilution of dichlorvos or 1:2000 dilution of beta-cypermethrin can be sprayed.
Boxwood leafroller: Recently the green hedges and planting blocks of Chinese boxwood have been damaged by this larva, and the damage symptoms are relatively obvious, so control should be carried out promptly on sunny days. For control chemicals, 1:1000 dilution of nicotine emulsion or 1:1000 dilution of Kuaishaling can be sprayed, and once more after 10 days.
Lawn pests: Entering August, it is the peak damage period of larvae of cotton leafworm, silver-marked moth, and black cutworm, especially cool-season turf such as tall fescue, which suffers more severe damage because it is tender and green. Upon inspection, a very small number of young larvae have recently been seen. For control of such pests, the spraying time should be chosen in the evening. For control chemicals, 1:1000 dilution of phoxim or 1:1000 dilution of Dachongling can be sprayed or irrigated.
Scale insects: Entering August, the main scale insect species to control include: crape myrtle felt scale on crape myrtle, camphor shield scale on camphor, pomegranate felt scale on flowering pomegranate, white wax mealybug on golden-leaf privet, and Japanese wax scale on French holly, etc. For all kinds of scale insects, control should be carried out promptly on sunny days as soon as possible. For control chemicals, 1:1500 dilution of imidacloprid or 1:1000 dilution of emamectin benzoate-phoxim emulsion can be sprayed.
Golden-leaf privet leaf-mining flea beetle: At present, it is exactly the adult activity and feeding period of this insect. It is predicted that in early August a new generation of young larvae will appear and cause leaf-mining damage. In the near future, 1:1000 dilution of Kuaishaling can be used to control adults, and in early August 1:1000 dilution of Kuaishaling can be used to control the leaf-mining larvae, so as to control their damage.
Leafhoppers: Mainly harm shrubs such as redleaf plum and osmanthus. When this insect causes damage, adults and nymphs exist at the same time. At present, redleaf plum on roads has been found to be obviously damaged. Entering August is even more the peak damage period, so inspection and control should be carried out promptly. It can be controlled by continuously spraying 1:2000 dilution of beta-cypermethrin or 1:1000 dilution of nicotine emulsion 2-3 times, with an interval of 10 days.
Spider mites: Commonly known as red spiders. Recent investigation found damage on plants such as pagoda tree and cherry blossom, causing symptoms such as loss of green color, discoloration, curling, and drooping of damaged leaves. When spider mites cause damage, adults, nymphs, and eggs exist at the same time, so regular inspection and control should be carried out. It can be controlled by spraying 1:1000 dilution of dicofol on the back of leaves, and once more after 7-10 days.

Cutting propagation technology of Photinia × fraseri

In production, Photinia × fraseri is mainly propagated by cuttings. Cutting propagation has the characteristics of low cost, simple operation, and high survival rate. It is a propagation technology that can be produced in ordinary plastic greenhouses and is suitable for promotion and application in most nurseries. Now let us take a look at the cutting propagation technology of Photinia × fraseri!

Cutting preparation for Photinia × fraseri

Choose field land with good drainage, fields that dry after rain, a relatively low groundwater level, convenient transportation, and a stable water source to build the nursery. For cutting in a single-span greenhouse, greenhouse film should be covered, plus a shade net. After the ground inside the greenhouse is leveled, build a ground-level cutting seedbed, with a width of about 100 cm. Install 10-12 cm high baffles around it, and lay a layer of fine sand at the bottom to facilitate drainage. The cutting substrate can be vermiculite plus peat, or clean yellow subsoil plus fine sand. The seedbed and substrate should be disinfected with fungicides and insecticides to prevent pests and diseases.

Cutting method for Photinia × fraseri

1. Cutting time: The requirements of Photinia × fraseri for cutting time vary by region. In the middle and lower reaches of the Yangtze River, spring, summer, and autumn are better. Generally speaking, temperatures between 15-35°C are all acceptable, and 20-30°C is most suitable. Therefore, late April to late June and late August to mid-October are the golden seasons for cutting Photinia × fraseri.

2. Selection of cuttings: Select vigorous, semi-lignified one-year-old branches as cuttings. Cut the cuttings to a length of 3-5 cm, with flat cuts at both the upper and lower ends. In the golden cutting season, because the temperature is suitable, generally half a leaf is retained. According to experience, retaining a little less than half for large leaves and a little more than half for small leaves is more appropriate. Pay attention to keeping the cuttings moist, shading, and sprinkling water. When cutting the cuttings, it is best to use special scissors, which make smaller wounds than ordinary flat-mouth scissors. The cutting wound has phloem inward and xylem slightly concave toward the center, making it easy for the cuttings to produce callus tissue and take root, with a high survival rate. It is best to choose cloudy days, before 10 a.m., and after 4 p.m. for cutting and inserting cuttings.

3. Cutting method: The rooting time of Photinia × fraseri cuttings can be advanced from 40 days to 7-15 days by using rooting agents, so before cutting, the cuttings should first be treated for rooting. Commonly used rooting agents include finished products ABT and Guoguang, and biochemical raw materials naphthalene acetic acid and indolebutyric acid. Before cutting, first water the seedbed thoroughly. The cuttings should not be inserted too deeply into the soil, generally 2/3 of the cutting. Use 400-700 plants per square meter. The leaves at the top of the cuttings should face the same direction so that they receive uniform light, which is conducive to early rooting and early sprouting. After inserting, water thoroughly again. After the moisture on the leaves dries, spray 600-800 times dilution of thiophanate-methyl or chlorothalonil to prevent disease. Finally, cover the entire seedbed tightly with a small arched greenhouse film.

Post-cutting management of Photinia × fraseri

1. Shading and topdressing: From cutting to rooting and sprouting, shading is required, maintaining a shading rate above 75%. After cutting, foliar topdressing should be carried out frequently, which can be done together with spraying chemicals for disease prevention. From callus formation to young root growth, spraying a nitrogen fertilizer solution at a concentration of 50×10-6 is sufficient. After roots form in large numbers and before transplanting, the nitrogen fertilizer concentration can be increased to 100×10-6 to 150×10-6.

2. Pest and disease prevention: After cutting, pest and disease control should be strengthened. Immediately after cutting is completed, spray 800 times dilution of carbendazim and thiophanate-methyl. After that, spray once every 5-7 days. After rain, fungicides must be sprayed promptly. During the cutting period, anthracnose is mainly likely to occur, requiring periodic control. The main control chemicals include anthracnose Fumei, mancozeb, and chlorothalonil. Pests mainly include aphids and moth larvae. The main control chemicals include imidacloprid and beta-cypermethrin.

3. Strengthen management: After 15 days, some cuttings begin to root, and the moisture content of the substrate should be appropriately reduced, generally maintaining about 40%. When more than 50% of the cuttings begin to root, ventilation can be gradually opened by removing the film, and shading can be reduced to about 50%. When all cuttings have rooted and more than 50% have leafed out, gradually remove the greenhouse shade net and film, give relatively sufficient light, and begin hardening the seedlings.

4. Hardening and potting: For potting rooted seedlings, the medium is 80% peat + 20% perlite. Generally, lime should be added to peat to adjust the pH value, while supplementing calcium. When potting seedlings, generally do it so that they are lifted, planted, and watered together. During the seedling stage, frost damage is likely to occur, so small seedlings are best overwintered in a greenhouse, or reduce water supply and do not fertilize. In summer high temperatures, it is best to spend the summer in a shade shed. Water management should pay attention to drying and wetting alternately. For fertilizer management, generally mix 4 kg of slow-release fertilizer into each cubic meter of medium when potting, and after potting regularly apply 700-1000 times dilution of nitrogen water-soluble fertilizer.