Does Salvia splendens get pests? Prevention and control methods for 3 diseases and 2 pests
When we grow plants, if the environment is unsuitable or the care methods are improper, it can cause the plants to get pests, and even plants with strong disease resistance and vitality are no exception. So does Salvia splendens get pests? The answer is yes. What should you do if it gets pests? Let's take a look at the prevention and control methods for Salvia splendens pests and diseases.
Does Salvia splendens get pests?
Salvia splendens can also get pests. The pests that are relatively likely to appear are red spider mites and aphids. They feed on the sap in the Salvia splendens plant, causing a lack of nutrients in the leaves, roots and stems, leading to wilting, yellowing or death of the plant, and they can also trigger other diseases, posing a considerable threat.
Prevention and control: The main preventive measures for red spider mites and aphids are to keep the environment clean, tidy, well ventilated, and with suitable temperature and light, etc. When pests appear, they need to be removed promptly. In addition to a damp cloth and a brush, omethoate emulsion at 1500 times dilution can also be sprayed.
Prevention and control methods for Salvia splendens pests and diseases
1. Viral disease
Symptoms: Viral disease has four types of symptoms, namely mosaic type, yellowing type, necrosis type, and deformity type. Its cause is that pests transmit the virus to the Salvia splendens plant, and the main transmitter is aphids. From this, it can be seen how important it is to prevent aphids and other pests.
Prevention and control: When sowing, disinfect the seeds, for example, soaking them in a 10% trisodium phosphate solution for 20 minutes, etc., which can effectively reduce the occurrence of the virus. In addition, usually spray some pesticides to prevent aphids, such as 90% trichlorfon at 1000 times dilution, etc.
2. Leaf spot disease
Symptoms: Dark brown lesions appear on the leaves of Salvia splendens, and lesions may also appear on the stems and petioles. At first, the lesions are relatively small, but if not treated in time, they will gradually expand. In the end, the lesions may become irregular in shape, with concentric rings at the edges, and the plant will eventually turn yellow and weaken.
Prevention and control: When planting, the density should not be too high, ensuring that the plants are properly spaced. If the branches and leaves become intertwined during growth, the dense branches need to be pruned promptly. After the disease occurs, 50% thiophanate at 1000 times dilution can be used for treatment.
3. Downy mildew
Symptoms: The base of the leaf is affected first, then it develops upward. Pale yellow lesions first appear on the leaf surface, nearly round or polygonal in shape. Then, when the air is relatively humid, frost-like mold spots form, and finally the leaves wither and die.
Prevention and control: When watering, try to use a small amount of water and avoid flooding irrigation. On rainy days, drainage is needed to prevent waterlogging. When the disease occurs, watering should be controlled, and the air humidity should be reduced, then spray 400-600 times dilution HILOT Kai Shuang.
Prevention and control techniques for cineraria pests and diseases
Cineraria powdery mildew mostly occurs at the seedling stage, mainly harming the leaves, and later it can also harm the flower buds and flowers. In the early stage of the disease, white powdery round spots appear on the leaf surface, but they are not obvious. The lesions gradually expand into round spots or irregular pale yellow large spots, on which many red powders grow. When the environmental humidity is relatively high, large white powdery patches cover the entire leaf, causing the leaves to twist, curl, and wither. In severe cases, the pedicels and petals can also be affected. Infected plants are short, with small, deformed flowers, and they wither prematurely.
Prevention and control methods:Strengthen cultivation management, pay attention to ventilation, do not place pots too densely, do not water too much, and do not allow water to accumulate on the leaves. Remove diseased plants as soon as they are found.
In the early stage of the disease, spray 70% thiophanate-methyl at 1000 times dilution, or 25% carbendazim wettable powder at 500 times dilution, or 25% triadimefon wettable powder at 2000 times dilution for prevention and control. Spray once every 10-15 days, for 2-3 consecutive times. Whitefly, also known as small white moth and white fly. Cineraria, chrysanthemum, Salvia splendens, nasturtium, Dianthus, marigold, geranium, Calendula, fuchsia, pansy, poinsettia and many other plants can all be affected. Mainly adults and larvae gather on the undersides of host plant leaves and suck sap to cause damage. In severe cases, the leaves fade, wilt, or even dry up, directly affecting the growth and development of the flowers. At the same time, each insect stage can also secrete honeydew, induce sooty mold, and is also an important vector insect for transmitting plant viruses.
This insect can occur for more than a dozen generations a year, and can reproduce all year round in greenhouses. The larval damage period is 8-10 days, and it overwinters on greenhouse plants in various insect stages.
Prevention and control methods:Strengthen plant quarantine, strictly prohibit all kinds of flower seedlings carrying insects from entering greenhouses or plastic tunnels, so as to reduce their overwintering rate.
Clear weeds around plastic tunnels and greenhouses to reduce insect sources. When insect infestation is found, 80% dichlorvos can be mixed with water at 1:2 and atomized for fumigation, using 1 milliliter of stock solution per square meter, once every 5-7 days, for 5-7 consecutive times. Doors and windows should be tightly closed during fumigation. Or use 2.5% fenpropathrin at 2000 times dilution, or 20% fenvalerate at 2000 times dilution, spraying once every 6 days, for 2-3 consecutive times.
Using yellow plastic boards coated with sticky oil and inserting them in greenhouses or plastic tunnels is very effective for trapping and killing adults.
Maintain and utilize natural enemy insects, such as Chrysopa sinica, Encarsia formosa, etc.
In addition, cineraria is also harmed by aphids, chrysanthemum leaf miners, etc., and can be controlled by referring to the methods introduced for other flowers.
Prevention and control of dahlia pests and diseases
Dahlia is also called dahlia pinnata, heavenly bamboo peony, sweet potato peony, sweet potato flower, dali flower, passionflower and foreign chrysanthemum. It is a perennial herb in the Asteraceae family. The colors of dahlia are brilliant and colorful, including red, yellow, orange, purple, white and other colors, very attractive. Dahlia adapts to different climates and soil qualities across the country, has few pests and diseases, is easy to manage, and is best for propagation. But it is often harmed by the following pests and diseases:Dahlia mosaic virus disease
Symptoms After the leaves are damaged, spots appear, and along both sides of the leaf veins there is brownish green, with semi-transparent "vein clearing" appearing. Pale yellow patches appear on the diseased leaves, the leaves wrinkle, growth stagnates, and the plant is short. Plants grown from virus-carrying roots rarely reach normal height.
Pathogen Dahlia Mosaic Virus. The virus particles are regular icosahedrons, transmitted by aphids and leafhoppers, and can also be transmitted through grafting. This virus can also infect zinnia, snakehead chrysanthemum, coreopsis and petunia, etc. In addition, cucumber mosaic virus (CMV), tobacco necrosis virus (TSV) and tomato spotted wilt virus (TSWV) can also cause viral disease in dahlia.
Prevention and control methods
1. The tuberous roots or sprouted buds of diseased plants cannot be used as propagation material.
2. Observe carefully and promptly pull out and burn diseased plants.
3. Spray 50% malathion at 1000 times dilution or 40% dimethoate at 1500 times dilution, 25% carbaryl at 800 times dilution to control virus-transmitting pests.
Dahlia gray mold
Symptoms The flower parts are easily affected and turn brown, then soft rot occurs. In severe cases, the flower buds cannot open, and gray mold (pathogen fruiting bodies) grows on them. Therefore, gray mold is also called flower rot. When it occurs on leaves, nearly round to irregular large lesions appear. The lesions often occur at the leaf margins, light brown to brown, sometimes showing concentric rings, water-soaked, and gray mold grows when humidity is high. Stem lesions are brown, sometimes showing concentric rings, water-soaked, and gray mold grows when humidity is high. Stem lesions are brown, irregular in shape, and in severe cases the stem softens and breaks, making it a major disease of dahlia.
Pathogen Botrytis cinerea Pers., belonging to Deuteromycotina. Conidiophores are slender, branched, sometimes nearly dichotomous near the top, with single-celled, ovoid conidia borne on short stalks, usually producing black, irregular sclerotia.
Transmission route The pathogen mainly overwinters as sclerotia with diseased plant residues. Under suitable conditions, the sclerotia grow conidiophores and produce conidia, causing secondary infection. The conidiophores produced on the lesions produce conidia, causing primary infection. The conidia produced on the lesions rely on wind and rain for transmission, causing re-infection. Damage is severe in rainy seasons, and the pathogen has a wide host range.
Prevention and control methods
1. Because Botrytis cinerea is both parasitic and saprophytic, promptly cut off diseased flowers and leaves and bury them deeply.
2. Practice crop rotation. Or replace with new pathogen-free soil.
3. Strengthen cultivation management, avoid planting too densely, so as to facilitate ventilation and light transmission. When watering, do not pour water over the plants, so as to avoid splashing water droplets and spreading the pathogen. After rain, pay attention to draining accumulated water.
Dahlia powdery mildew
Symptoms Dahlia powdery mildew harms leaves, tender buds, flower stalks and flower buds. A layer of white powdery substance, namely conidia, is produced on the surface of the diseased parts. Several small lesions on the leaves can connect into large lesions. After being damaged, the plant is short, and the leaf surface is uneven or curled, and the tender shoots develop abnormally. After the flower buds are damaged, they cannot bloom or only produce deformed flowers. In severe cases, the leaves can dry up, or even the whole plant can die. In autumn and winter, gray mycelium and a few small black dots are produced. The small black dots are cleistothecia.
Pathogen Erysiphe polygoni DC., belonging to Ascomycetes, Erysiphales. The mycelium grows on both the front and back sides of the leaves.
Transmission route Overwinters as mycelium. When the temperature rises to 18°C-25°C the following year, the mycelium begins to grow and produces a large number of conidia. When environmental conditions are suitable, it germinates and grows mycelium, produces haustoria, and absorbs nutrients from the tissue. High temperature and high humidity favor the disease.
Prevention and control methods
1. Prune and destroy diseased plants.
2. During the disease season, use 15% triadimefon wettable powder at 1500 times dilution, or 70% thiophanate-methyl wettable powder at 700 times dilution, or 50% carbendazim wettable powder at 500 times dilution for spray control
Dahlia bacterial wilt
Symptoms After the roots and tuberous roots are infected by the pathogen, they turn brown and rot, and the aboveground leaves wilt, droop and die. When the diseased roots and stems are cut crosswise, the xylem is yellowish brown, and bacterial pus overflows.
Pathogen Pseudomonas solanacearum E.F. smith.
Transmission route The pathogen can live saprophytically in diseased plant residues or soil, and under high temperature and high humidity environmental conditions it multiplies in large numbers, and invades the host through wounds. When transplanting in hot and rainy seasons, if the soil or fertilizer carries the bacterial wilt pathogen, the disease is most likely to occur.
Prevention and control methods
1. Cultivate disease-free seedlings and avoid selecting propagation material in diseased areas.
2. Do not use soil where this disease has occurred for planting. Strengthen seedling management and avoid causing wounds. Water appropriately, and prevent irrigation water from diseased areas from flowing to healthy plants. Diseased plants should be pulled out and burned.
3. Improve the soil: Spread 100-150 kg of slaked lime per mu, apply sufficient decomposed farmyard manure, and turn and level the soil, making the soil fertile, loose, and slightly alkaline, so as to inhibit pathogen reproduction and enhance plant resistance.
4. Chemical control:
1) Promptly remove and burn diseased plants, pour 2% formaldehyde solution or 20% limewater into each hole for disinfection, and lime powder can also be spread.
2) In the early stage of the disease, use streptomycin at 4000 times dilution or 30% DT (copper succinate-glutarate) wettable powder at 500 times dilution, 70% DTM wettable powder at 500-600 times dilution for spraying, or 77% Kocide wettable powder at 500 times dilution. Spray once every 7-10 days, for 3-4 consecutive times.
3) The above agents can also be used to drench the roots, with 0.5 kg of liquid per plant, combined with spraying, once every 7-8 days, for 3-4 consecutive times.
Dahlia dark leaf spot disease
Symptoms Circular or semicircular dark green concentric-ring lesions occur on the leaf surface and leaf margins. The lesions later turn dark brown, with the center grayish green. Small black dots are scattered on the surface of the lesions. When the disease is severe, the leaves wilt and droop.
Pathogen Phyllosticta dahliaecola Brunaud., called dahlia leaf spot fungus, belonging to Deuteromycotina fungi.
Transmission route The pycnidia remain on the surface of the ground with diseased residues to overwinter. The following year, conidia are released and germinate, producing germ tubes that invade the host. Later, pycnidia and conidia are produced again in the diseased parts, spreading through wind and rain for re-infection. A temperature of 21°C favors its occurrence or epidemic.
Prevention and control methods
1. After harvest, thoroughly remove diseased residues and burn them in a concentrated way or plow the land deeply to reduce the primary infection source.
2. In the early stage of the disease, spray 75% chlorothalonil wettable powder at 500 times dilution, 40% carbendazim-sulfur suspension at 500-600 times dilution, 50% mixed sulfur suspension at 500 times dilution, 1:1:200 Bordeaux mixture, 77% Kocide wettable powder at 500 times dilution, 50% copper succinate-glutarate (DT) wettable powder at 400-500 times dilution, once about every 10 days, for 1 or 2 treatments.
Dahlia flower blight
Symptoms The corolla is affected. The top part of the petals is light brown, with circular or nearly circular spots occurring, which then spread on the petals. The petals wither from the affected area and gradually turn brown and die. The outer corolla is affected and develops toward the inner corolla, causing the rotting petals to droop.
Disease conditions The pathogen can grow at 5-25°C, and grows best at 20-25°C. The disease is severe in autumn with more rain and on large double flowers.
Pathogen Itersonilia perplexans Derx, belonging to fungi Deuteromycotina, Moniliales, Itersonilia, flower blight Itersonilia. The mycelium of the pathogen easily forms clamp connections, and some cells of the mycelium form sterigmata, bearing asymmetrical colorless ballistospores, which are forcibly discharged. The pathogen surviving on diseased flower residues is the infection source of the disease.
Prevention and control methods Refer to chrysanthemum black spot disease. Dahlia southern blight
Symptoms Wet rot occurs at the base of the plant, initially brownish black, then white silky mycelium is produced, and sclerotia the size of rapeseeds are formed.
Pathogen Sclerotium rolfsii Sacc., belonging to Deuteromycotina. The mycelium is white, loose or aggregated into linear forms and closely attached to the substrate, forming sclerotia. The sclerotia are small (0.5-1.0 mm in diameter) and neat, initially white, later turning yellowish brown, with a grayish white interior.
Transmission route The pathogen survives in the soil and plant residues for many years as mycelium and sclerotia, and infects the host from the root crown. The pathogen has a wide host range, and iris, orchid, peony, pyrethrum, peach, pear, etc. are also often infected, causing damping-off, root rot, basal rot and fruit rot.
Prevention and control methods
1. Pull out diseased plants, collect the sclerotia in the soil and burn them in a concentrated way, spread lime in the diseased holes, or fill them with toxic soil made by mixing 70% quintozene powder with new soil at 100 times for disinfection.
2. In the early stage of the disease, use 50% thiophanate wettable powder at 500 times dilution or 50% carbendazim wettable powder at 500 times dilution to irrigate the stem base of diseased plants, and irrigate again after 7-10 days.
Phassus excrescens
Phassus excrescens, also known as the oriental swift moth, belongs to Lepidoptera, Hepialidae.
Distribution and damage Distributed in Heilongjiang, Jilin, Liaoning, the former Soviet Union, Japan and other places. It harms many kinds of flowers and trees.
Damage symptoms Larvae bore into branches and trunks. The borehole entrance often appears as a sunken ring, and is covered with wood chips stuck together by silk threads, forming a wood chip packet.
Morphological characteristics Adult Body length 35-44 mm, wingspan 66-70 mm. Body powdery brown to tea brown. Antennae short, linear. Forewings with ring-shaped markings along the anterior margin, with 1 dark, slightly green, angular marking in the center, and 2 broad brown diagonal bands on the outer edge of the marking. Hindwings narrow and small, abdomen large. Egg Spherical, diameter 0.6-0.7 mm, black, slightly glossy. Larva Dark brown, thorax and abdomen dirty white, cylindrical, body with yellowish brown tubercles, mature larva body length 44-57 mm.
Life history and habits In Liaoning, mostly 1 generation per year, a few 2 generations per year, overwintering as eggs on the ground, or as larvae at the base. Hatching begins in mid-May of the following spring. In early June, they move to the stems of fruit trees, forest trees or weeds and other plants to feed. Pupation begins in early August and ends in late September. They emerge as adults in late August. The peak emergence period is mid-September, and the last are seen in mid-October. After emerging, adults mate and lay eggs. They overwinter as eggs. Some larvae that hatch later, or larvae whose development is delayed by other disturbances, overwinter as larvae. The following year, in early July, they begin to emerge as adults and then lay eggs, completing 1 generation in 2 years. Adults mostly emerge from 16:00-18:00. During the day, adults mostly hang motionless on tree trunks, undergrowth or weeds, and only begin to fly, mate and lay eggs after sunset. Adults are negatively phototactic. After mating, they lay eggs immediately. There is no fixed place for egg laying. Most, with trembling of both wings, lay eggs one by one, and some lay eggs while mating; most lay eggs without mating. The number of eggs laid by females ranges from several hundred to several thousand.
Prevention and control methods
1. Prune off seedlings and branches with wood chip packets.
2. Chemical control: From late May to early June, when young larvae are active on the ground, spray 50% parathion at 1000 times dilution on the ground. When middle-instar larvae move into the trunk, drip 50% dichlorvos at 10 times dilution into the insect holes.
Atractomorpha sinensis
Grasshoppers, commonly known as locusts, are widely distributed. The flowers they harm include Impatiens, cockscomb, Salvia splendens, pansy, snapdragon, globe amaranth, Calendula, zinnia, daisy, chrysanthemum, Echinacea, Chinese rose, jasmine, hibiscus, dahlia, gardenia, etc.
Damage symptoms Young nymphs like to gather and feed on leaves. The damaged leaves appear net-like. Shortly afterward, they disperse to feed, causing leaf notches and holes. In severe cases, only the main veins remain on the entire leaf.
Morphological characteristics Adult Body length 21-31 mm, light green to brown and pale yellow. The head protrudes forward. The hind legs are well developed as jumping legs. Forewings green. Hindwings red at the base, green at the tip. Egg Egg masses are sealed on the outside with a yellowish brown secretion. Single eggs are milky white, oval. Nymph Initially light green, with white spots, resembling the adult, wingless, with only wing buds. Life history and habits This insect has 2 generations a year in the Yangtze River basin and other areas. It overwinters as eggs in the soil. The eggs hatch in May-June of the following year. In early July, the first-generation adults begin to lay eggs. Mid-to-late July is the peak egg-laying period. The second-generation nymphs begin hatching in late July, and mid-to-early August is the peak hatching period. From mid-to-late September to early October, the second-generation adults begin to lay eggs, and late October to early November is the peak egg-laying period.
Prevention and control methods
1. When young nymphs gather to cause damage, capture and kill them manually.
2. Spray 50% fenitrothion emulsion at 1000 times dilution, or 25% phosmet at 1000 times dilution.