成长记
cclecombe
2017年09月20日
I went to get some cactus soil to set these guys up again as well as all of my other cacti and succulents in insuitable soil, but they hadn't any. I read online somewhere that when the tips of the leaves start to go red, its a sign roots are about to come so hopefully I can get some soil before they shoot out!
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meriunkat：yes!🙌👍
文章
Dummer. ゛☀
2017年09月20日
Soil: Unlike most other cacti Pereskiopsis will put up with a lot of organic material in their soil. Although you should not use a rain forest mix you can and should have a soil mix that is a little more than 75% organic soil. We do this because unlike most other cacti, Pereskiopsis are heavy feeders. They grow far more quickly thanks to their leaves, and their roots are far more reaching. The other 25% should consist of an even mix of perlite, pumice, rock and sand. All of these four provide excellent drainage oxygen flow in the soil. Root rot is common in Pereskiopsis but is easily avoided by adding these.
Light: As with just about every cactus a lack of light will really harm them if you expect growth and continue to water them. You will wait for a long time if you do not have an artificial light source and humidity. Pereskiopsis live in very tropical, wet and humid regions of Central and South America. This is easy to recreate with your grow light and indoor greenhouse set up. But you must be careful to allow air circulation. This is one of the number one killers of cactus and Pereskiopsis in general behind over watering. If you have an indoor greenhouse you can easily do this by opening up the tent for several hours a day and choosing one day a week in which it is open all day. You should have two angles for air circulation to navigate. No artificial fans are need but can be helpful.
Lighting requirements for Pereskiopsis plants are about 10-14 hours of light a day. Find a balance that fits your lifestyle and that of the plants. If they react negatively toward your specifications, make the appropriate changes.
If you are just growing them during the summer, most northern states and even portions of Canada can maintain Pereskiopsis outside. The months of June, July and August will be perfect for Pereskiopsis in clay pots. Do not bother watering them and just let the rain take care of them. If you are in the western states which are much drier, just water them when the soil becomes dry. Believe it or not these cacti will be tolerant of regular potting soil in a sunny and warm location with good air circulation.
Water: Unlike most other cacti, Pereskiopsis have the unique property of wanting more water. Don’t make the common mistake though, most cacti would prefer if you watered them more. However the soil, heat and light that you have are probably not enough to accommodate them. Even in their natural habitat, cacti would prefer more water than they receive.
Grower’s Tips
Growing Pereskiopsis is not difficult at all. In fact the plant is quite tolerant of many mistakes you might throw at it, but there are some considerations you must take before planting your new grafting stock. Depending on the number you have and how you will want to display them will dictate how they are planted. Another consideration is whether you received them as cuttings or as fully rooted plants. A tray that does not separate the different plants is perfectly acceptable. However to make grafting easier as well as future cuts, it’s best to use a cell that separates the plants, one per cell. This will also make it easy to separate them when you are ready because the roots are very aggressive and will branch out.
Light: As with just about every cactus a lack of light will really harm them if you expect growth and continue to water them. You will wait for a long time if you do not have an artificial light source and humidity. Pereskiopsis live in very tropical, wet and humid regions of Central and South America. This is easy to recreate with your grow light and indoor greenhouse set up. But you must be careful to allow air circulation. This is one of the number one killers of cactus and Pereskiopsis in general behind over watering. If you have an indoor greenhouse you can easily do this by opening up the tent for several hours a day and choosing one day a week in which it is open all day. You should have two angles for air circulation to navigate. No artificial fans are need but can be helpful.
Lighting requirements for Pereskiopsis plants are about 10-14 hours of light a day. Find a balance that fits your lifestyle and that of the plants. If they react negatively toward your specifications, make the appropriate changes.
If you are just growing them during the summer, most northern states and even portions of Canada can maintain Pereskiopsis outside. The months of June, July and August will be perfect for Pereskiopsis in clay pots. Do not bother watering them and just let the rain take care of them. If you are in the western states which are much drier, just water them when the soil becomes dry. Believe it or not these cacti will be tolerant of regular potting soil in a sunny and warm location with good air circulation.
Water: Unlike most other cacti, Pereskiopsis have the unique property of wanting more water. Don’t make the common mistake though, most cacti would prefer if you watered them more. However the soil, heat and light that you have are probably not enough to accommodate them. Even in their natural habitat, cacti would prefer more water than they receive.
Grower’s Tips
Growing Pereskiopsis is not difficult at all. In fact the plant is quite tolerant of many mistakes you might throw at it, but there are some considerations you must take before planting your new grafting stock. Depending on the number you have and how you will want to display them will dictate how they are planted. Another consideration is whether you received them as cuttings or as fully rooted plants. A tray that does not separate the different plants is perfectly acceptable. However to make grafting easier as well as future cuts, it’s best to use a cell that separates the plants, one per cell. This will also make it easy to separate them when you are ready because the roots are very aggressive and will branch out.
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文章
Dummer. ゛☀
2017年09月20日
Succulents are an invaluable plant, because they are beautiful and nearly indestructible. Succulents are water-retaining and are adapted to arid climates and soil conditions. High temperatures and low precipitation have forced these plants to store water in their leaves, stems, and roots. This adaptive mechanism has resulted in an incredible variety of different leaf forms and plant shapes.
Some of the best known succulents are cacti, which are a unique subgroup that has evolved into many different species. The Succulents also includes some well known plants such as Aloe and Agave. No matter which variety of succulent you are growing, however, their requirements are very similar:
Size and Placement
Place the largest most dramatic first and the smaller ones around them. Remember many succulents can’t be cut to a lower height after they have grown. When placing plants think about how tall the plant will get in the location.
Why are some succulents smaller and more expensive than the larger succulents?
The smaller varieties generally grow slower than the faster growing varieties thus they are often older.
Temperature
Succulents can handle the cold as well as the heat. Just like the desert which can have cold nights, a succulent can live in temperatures down to even 40 degrees F (5 degrees C).
Light
Succulents prefer light such as in the open garden or in a south-facing window. Some species will scorch if exposed to direct sunlight and the leaves will change to a brown or white as the tissues are destroyed. Watch the leaves as an indication of if the sun exposure is correct. A succulent without enough light, however, will begin to stretch with an elongated stem. If this happens, provide better light and prune your succulent back to its original shape.
Water
Succulents will need more water in the summer and during establishment. Water generously but allow the soil to dry in-between watering. This is why good drainage is important. In winter, the plant will go dormant so water it every other month. If you over-water you could cause plant rot. The succulent may look healthy at first during over-watering, but eventually will die as the rot has begun in the roots and isn’t showing above ground yet.
Over-Watering
Over-watered succulents will look discolored and soft—yellow or white with loss of color. Remove it from the pot and look for rotted roots. Rotted roots should be cut off and replant your succulent in a drier area.
Under-Watering
Under-watered succulents will stop growing and shed leaves or generate brown spots on their leaves.
Planting/Potting Soils
Your succulents should be planted in a soil that provides for good drainage. Succulents will benefit from an inorganic agent like perlite which will help aeration and drainage.
Fertilizer
Fertilize during summer growing season but stop entirely during the winter.
Some of the best known succulents are cacti, which are a unique subgroup that has evolved into many different species. The Succulents also includes some well known plants such as Aloe and Agave. No matter which variety of succulent you are growing, however, their requirements are very similar:
Size and Placement
Place the largest most dramatic first and the smaller ones around them. Remember many succulents can’t be cut to a lower height after they have grown. When placing plants think about how tall the plant will get in the location.
Why are some succulents smaller and more expensive than the larger succulents?
The smaller varieties generally grow slower than the faster growing varieties thus they are often older.
Temperature
Succulents can handle the cold as well as the heat. Just like the desert which can have cold nights, a succulent can live in temperatures down to even 40 degrees F (5 degrees C).
Light
Succulents prefer light such as in the open garden or in a south-facing window. Some species will scorch if exposed to direct sunlight and the leaves will change to a brown or white as the tissues are destroyed. Watch the leaves as an indication of if the sun exposure is correct. A succulent without enough light, however, will begin to stretch with an elongated stem. If this happens, provide better light and prune your succulent back to its original shape.
Water
Succulents will need more water in the summer and during establishment. Water generously but allow the soil to dry in-between watering. This is why good drainage is important. In winter, the plant will go dormant so water it every other month. If you over-water you could cause plant rot. The succulent may look healthy at first during over-watering, but eventually will die as the rot has begun in the roots and isn’t showing above ground yet.
Over-Watering
Over-watered succulents will look discolored and soft—yellow or white with loss of color. Remove it from the pot and look for rotted roots. Rotted roots should be cut off and replant your succulent in a drier area.
Under-Watering
Under-watered succulents will stop growing and shed leaves or generate brown spots on their leaves.
Planting/Potting Soils
Your succulents should be planted in a soil that provides for good drainage. Succulents will benefit from an inorganic agent like perlite which will help aeration and drainage.
Fertilizer
Fertilize during summer growing season but stop entirely during the winter.
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文章
Dummer. ゛☀
2017年09月19日
Cacti are remarkably durable and low in maintenance. The succulents need little more than sun, well drained soil and rare moisture. The pests and problems common to the plant group are minimal and usually easy to surmount. Cactus problems may range from sucking pests, like whitefly, to common rots from bacteria or fungal disease. One of the telltale signs of a problem is a soft, mushy cactus.
The arid gardener may ask, “Why is my cactus going soft?” Likely causes are disease, cultivation and improper site and ambient conditions.
Cacti generally have low moisture needs. They thrive in temperatures above 70 to 75 °F (21 to 24 °C) in sunny locations and require little supplemental nutrients. Potted plants need good drainage holes and a soil mix with plenty of grit. In-ground plants have similar requirements.
As with any plant, cacti can become diseased or damaged. A common problem is soft spots in the flesh of the plant. These may be discolored or corky around the spot and the center is mushy and wet. The reasons for such spots may be disease or simply mechanical injury to the pads and stems of the cacti. Cactus rot issues must be dealt with quickly to prevent spread to the rest of the plant and serious loss of vigor, which may become permanent.
Problems with Fungal and Bacterial Diseases
Bacteria and fungus are introduced to the plant from openings in the flesh. The open areas may be from insect or animal activity, damage from inanimate objects or heavy weather, such as hail. The action of injury isn’t important, but the damage from fungal spores or bacteria is crucial.
Warm, moist conditions accelerate the production of fungi spores and increase bacterial production. Once the organism takes hold in your plant, you will see soft, mushy cactus. Symptoms to watch for include small sunken spots, discolored scabs, round soft areas surrounded by fruiting bodies, and black or other colored dots on the surface of the cacti skin. You may even notice some oozing of your cactus plants.
Treating
Cactus problems that have gotten into the root usually result in a slowly dying plant, while topical issues in the upper body can be treated easily. Most cacti respond well to excising the diseased tissue. Use a sharp sterile knife to dig out the damaged flesh and allow the hole to dry out. Don’t water overhead as the wound closes.
If the damage has infected the roots, there is very little you can do. You can try to repot the plant, removing diseased soil and replacing it with sterile soil. You should wash the roots off well before replanting in fresh potting medium.
A soft, mushy cactus can also be saved by taking cuttings and letting them root for a fresh new plant. Allow the cutting to callus over for a few days before you insert it into sand. Rooting the cutting may take several weeks. This method of propagation will produce a healthy cactus that is the same as the parent plant.
The arid gardener may ask, “Why is my cactus going soft?” Likely causes are disease, cultivation and improper site and ambient conditions.
Cacti generally have low moisture needs. They thrive in temperatures above 70 to 75 °F (21 to 24 °C) in sunny locations and require little supplemental nutrients. Potted plants need good drainage holes and a soil mix with plenty of grit. In-ground plants have similar requirements.
As with any plant, cacti can become diseased or damaged. A common problem is soft spots in the flesh of the plant. These may be discolored or corky around the spot and the center is mushy and wet. The reasons for such spots may be disease or simply mechanical injury to the pads and stems of the cacti. Cactus rot issues must be dealt with quickly to prevent spread to the rest of the plant and serious loss of vigor, which may become permanent.
Problems with Fungal and Bacterial Diseases
Bacteria and fungus are introduced to the plant from openings in the flesh. The open areas may be from insect or animal activity, damage from inanimate objects or heavy weather, such as hail. The action of injury isn’t important, but the damage from fungal spores or bacteria is crucial.
Warm, moist conditions accelerate the production of fungi spores and increase bacterial production. Once the organism takes hold in your plant, you will see soft, mushy cactus. Symptoms to watch for include small sunken spots, discolored scabs, round soft areas surrounded by fruiting bodies, and black or other colored dots on the surface of the cacti skin. You may even notice some oozing of your cactus plants.
Treating
Cactus problems that have gotten into the root usually result in a slowly dying plant, while topical issues in the upper body can be treated easily. Most cacti respond well to excising the diseased tissue. Use a sharp sterile knife to dig out the damaged flesh and allow the hole to dry out. Don’t water overhead as the wound closes.
If the damage has infected the roots, there is very little you can do. You can try to repot the plant, removing diseased soil and replacing it with sterile soil. You should wash the roots off well before replanting in fresh potting medium.
A soft, mushy cactus can also be saved by taking cuttings and letting them root for a fresh new plant. Allow the cutting to callus over for a few days before you insert it into sand. Rooting the cutting may take several weeks. This method of propagation will produce a healthy cactus that is the same as the parent plant.
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文章
Dummer. ゛☀
2017年09月19日
Root-knot nematodes are microscopic, plant-parasitic roundworms in the genus, Meloidogyne. Normally they exist in sandy soil in hot climates or short winters, but they have spread to our region as well. In Missouri alone 40 species of parasitic nematodes exist. About 2000 plants are susceptible to infection by these nematodes, and they can cause global crop loss. Root-knot nematode larvae infect plant roots that drain the plant’s ability to take up water and sufficient nutrients. Because of their microscopic size the nematodes go unnoticed until serious symptoms appear. The pathogenic nematodes can allow entrances for root rots, and wilts. They can also transmit viral diseases.
Symptoms and Diagnosis
A plant infected with root-knot nematodes often exhibits the same signs of nutrient deficiency. It may be stunted, yellowed, or wilted, and can lead to premature death of the plant. Below the ground, the roots of the plant are swollen or knotted with root galls, and unless a plant is removed from the soil to examine the roots, the cause of the poor plant growth remains undetected. The appearance of the galls on the roots can be confused with nitrogen-fixing nodules common in the legume family. However it is easy to distinguish between them, as the nitrogen nodules can be easily rubbed off while the nematode galls cannot be removed.
Life Cycle
The root-knot nematode is parthenogenic, that is a single female can reproduce without males and a new generation can occur every 28 days if conditions are ideal. Inside the gall, the enlarged female appears as a shiny white body, the size of a pinhead. She deposits 300 to 500 eggs in a protective jelly-like material. These glistening white to yellow egg masses are present on the root surfaces. Juveniles emerge from the eggs in the soil and penetrate between and through cells at the center of the root, usually near the growing tip. These larvae actively feed and remain at this same site. The juvenile stage can over-winter even under very unfavorable conditions. New adult nematodes develop from the larvae and start the cycle again.
Integrated Pest Management Strategies
1. Never buy or plant any stunted-yellowed plants. When a new plant’s roots are examined and its roots contain root knots that will not easily rub off, do not plant it. If someone gives you a division of their plant whose roots contain these root-knots, never add it to your garden because it will contaminate all of your healthy plants with the nematodes.
2. Keep plants healthy and avoid stressing plants and water plants during periods of high temperatures and drought. Also keep other insect pests and fungal diseases under control. Control weeds as they can act as hosts to these nematodes. Keep tools clean.
3. ;Rotate crops, planting nematode resistant plants when possible. It may take 3-5 years to kill off these nematodes before replanting the same plant.
4. Destroy any plants you discover that are infested with root-knot nematodes and don’t compost them. Replace all the soil before adding a new plant to this area.
5. Soil solarization has demonstrated some success in eliminating root-knot nematodes. Thoroughly moisten the soil and cover with clear plastic in full sun during the hottest months of the year. The soil must maintain these high temperatures for a period of at least 4-6 weeks to be effective. Re-moisten the soil under the plastic if it dries out.
6. No chemical controls are advised for home gardeners. Some restricted use chemicals are available for commercial, licensed applicators.
Symptoms and Diagnosis
A plant infected with root-knot nematodes often exhibits the same signs of nutrient deficiency. It may be stunted, yellowed, or wilted, and can lead to premature death of the plant. Below the ground, the roots of the plant are swollen or knotted with root galls, and unless a plant is removed from the soil to examine the roots, the cause of the poor plant growth remains undetected. The appearance of the galls on the roots can be confused with nitrogen-fixing nodules common in the legume family. However it is easy to distinguish between them, as the nitrogen nodules can be easily rubbed off while the nematode galls cannot be removed.
Life Cycle
The root-knot nematode is parthenogenic, that is a single female can reproduce without males and a new generation can occur every 28 days if conditions are ideal. Inside the gall, the enlarged female appears as a shiny white body, the size of a pinhead. She deposits 300 to 500 eggs in a protective jelly-like material. These glistening white to yellow egg masses are present on the root surfaces. Juveniles emerge from the eggs in the soil and penetrate between and through cells at the center of the root, usually near the growing tip. These larvae actively feed and remain at this same site. The juvenile stage can over-winter even under very unfavorable conditions. New adult nematodes develop from the larvae and start the cycle again.
Integrated Pest Management Strategies
1. Never buy or plant any stunted-yellowed plants. When a new plant’s roots are examined and its roots contain root knots that will not easily rub off, do not plant it. If someone gives you a division of their plant whose roots contain these root-knots, never add it to your garden because it will contaminate all of your healthy plants with the nematodes.
2. Keep plants healthy and avoid stressing plants and water plants during periods of high temperatures and drought. Also keep other insect pests and fungal diseases under control. Control weeds as they can act as hosts to these nematodes. Keep tools clean.
3. ;Rotate crops, planting nematode resistant plants when possible. It may take 3-5 years to kill off these nematodes before replanting the same plant.
4. Destroy any plants you discover that are infested with root-knot nematodes and don’t compost them. Replace all the soil before adding a new plant to this area.
5. Soil solarization has demonstrated some success in eliminating root-knot nematodes. Thoroughly moisten the soil and cover with clear plastic in full sun during the hottest months of the year. The soil must maintain these high temperatures for a period of at least 4-6 weeks to be effective. Re-moisten the soil under the plastic if it dries out.
6. No chemical controls are advised for home gardeners. Some restricted use chemicals are available for commercial, licensed applicators.
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文章
Dummer. ゛☀
2017年09月19日
Most plants growing in average garden soil in the St. Louis area receive sufficient nutrients from the soil that deficiencies are not a problem. The most notable exception is iron chlorosis of trees and shrubs, which is more likely to result from a high soil pH than a lack of iron in the soil. See below for more information on this deficiency. Also, because of the higher nitrogen requirement of turf grasses and leafy vegetables in the vegetable garden they may benefit from some additional nitrogen fertilizer. Also, nutrient deficiencies are likely to occur in plants growing in containers that are not fertilized regularly because of the reduced soil volume and the lower nutrient holding capacity of soil-less mixes used for container plants.
Following is some brief information on the symptoms of common nutrient deficiencies:
Macronutrients
Nitrogen
Lack of nitrogen shows up as overall yellow-green leaves instead of a dark green, yellowing and dropping of lower leaves (can be caused by many factors), and overall reduced plant size and slow growth. Although most garden plants receive adequate nitrogen from the soil and dissolved in rainwater, applying nitrogen in a complete, balanced fertilizer such as 20-20-20 once a year around perennials and shrubs is usually sufficient to provide adequate growth. Leafy vegetables can benefit from additional nitrogen. Most trees do not suffer from lack of sufficient nitrogen. Although lawns respond quickly and dramatically to the application of nitrogen, becoming green and lush, its use should be tempered, as this lush growth is also more susceptible to attack by insects and disease. Nitrogen in best applied to cool-season grasses in fall and on warm season grasses as they begin to grow in early summer. Nitrogen should be applied to container plants in a complete fertilizer, such as 20-20-20.
Phosphorus
Lack of phosphorus typically results in reduced growth and in some plants purplish foliage, especially older leaves. Although it may be observed on container grown plants most soils in Missouri contain ample phosphorus so more rarely would deficiencies be noticed in a garden situation. If you suspect your plants are showing symptoms of lack of phosphorus, have your soil tested. Then add phosphorus as required by the test results. Container grown plants require regular fertilizing with a complete fertilizer such as 20-20-20.
Potash
Again, lack of potash is rare in Missouri soils but deficiency symptoms typically result in stunted growth. Older leaves may yellow and leaf edges may roll up. If a deficiency is suspected have your soil tested and follow the recommendations provided with your soil test results. Container grown plants require regular fertilizing with a complete fertilizer such as 20-20-20.
Calcium, Magnesium and Sulfur
These three elements complete the macronutrients. They are frequently available in adequate amounts in St. Louis soils.
Micronutrients
Several micronutrients are required for good plant growth. These include: iron, manganese, copper, zinc, boron, chlorine, molybdenum, and nickel. Symptoms are almost entirely crop specific, hence, listing general symptoms of little use. Also, their identification can be difficult from symptoms alone. Some are well known and a plant disease reference of well-studied crops may show pictures of the classic symptoms of a particular nutrient deficiency on a crop. Frequently, however, short of sending leaf tissue off to a lab for analysis the gardener is left questioning whether the symptoms they are seeing are caused by a nutrient deficiency or not. If in doubt, treat the plant with a micronutrient fertilizer or a complete fertilizer containing micronutrients. Since most micronutrients are used in very small amounts the fertilizer will provide the plant what it needs if the soil is indeed lacking in a micronutrient. Follow the product’s label directions. In the St. Louis area the most commonly encountered micronutrient problem is with iron.
Iron
Lack of iron most notably causes what is referred to as iron chlorosis or yellowing leaves where the veins remain green. New growth is most affected. Lack of iron in the soil, a high soil pH (over 7) that restricts availability of iron in the soil, and environmental conditions can all result in iron chlorosis. For detailed information on iron chlorosis see the IPM page “Iron Chlorosis of Trees and Shrubs” herein. Potted plants showing iron chlorosis can be watered with a fertilizer containing iron or a specific iron fertilizer such as chelated iron.
Following is some brief information on the symptoms of common nutrient deficiencies:
Macronutrients
Nitrogen
Lack of nitrogen shows up as overall yellow-green leaves instead of a dark green, yellowing and dropping of lower leaves (can be caused by many factors), and overall reduced plant size and slow growth. Although most garden plants receive adequate nitrogen from the soil and dissolved in rainwater, applying nitrogen in a complete, balanced fertilizer such as 20-20-20 once a year around perennials and shrubs is usually sufficient to provide adequate growth. Leafy vegetables can benefit from additional nitrogen. Most trees do not suffer from lack of sufficient nitrogen. Although lawns respond quickly and dramatically to the application of nitrogen, becoming green and lush, its use should be tempered, as this lush growth is also more susceptible to attack by insects and disease. Nitrogen in best applied to cool-season grasses in fall and on warm season grasses as they begin to grow in early summer. Nitrogen should be applied to container plants in a complete fertilizer, such as 20-20-20.
Phosphorus
Lack of phosphorus typically results in reduced growth and in some plants purplish foliage, especially older leaves. Although it may be observed on container grown plants most soils in Missouri contain ample phosphorus so more rarely would deficiencies be noticed in a garden situation. If you suspect your plants are showing symptoms of lack of phosphorus, have your soil tested. Then add phosphorus as required by the test results. Container grown plants require regular fertilizing with a complete fertilizer such as 20-20-20.
Potash
Again, lack of potash is rare in Missouri soils but deficiency symptoms typically result in stunted growth. Older leaves may yellow and leaf edges may roll up. If a deficiency is suspected have your soil tested and follow the recommendations provided with your soil test results. Container grown plants require regular fertilizing with a complete fertilizer such as 20-20-20.
Calcium, Magnesium and Sulfur
These three elements complete the macronutrients. They are frequently available in adequate amounts in St. Louis soils.
Micronutrients
Several micronutrients are required for good plant growth. These include: iron, manganese, copper, zinc, boron, chlorine, molybdenum, and nickel. Symptoms are almost entirely crop specific, hence, listing general symptoms of little use. Also, their identification can be difficult from symptoms alone. Some are well known and a plant disease reference of well-studied crops may show pictures of the classic symptoms of a particular nutrient deficiency on a crop. Frequently, however, short of sending leaf tissue off to a lab for analysis the gardener is left questioning whether the symptoms they are seeing are caused by a nutrient deficiency or not. If in doubt, treat the plant with a micronutrient fertilizer or a complete fertilizer containing micronutrients. Since most micronutrients are used in very small amounts the fertilizer will provide the plant what it needs if the soil is indeed lacking in a micronutrient. Follow the product’s label directions. In the St. Louis area the most commonly encountered micronutrient problem is with iron.
Iron
Lack of iron most notably causes what is referred to as iron chlorosis or yellowing leaves where the veins remain green. New growth is most affected. Lack of iron in the soil, a high soil pH (over 7) that restricts availability of iron in the soil, and environmental conditions can all result in iron chlorosis. For detailed information on iron chlorosis see the IPM page “Iron Chlorosis of Trees and Shrubs” herein. Potted plants showing iron chlorosis can be watered with a fertilizer containing iron or a specific iron fertilizer such as chelated iron.
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文章
Dummer. ゛☀
2017年09月19日
Crown gall is a plant disease caused by the soil-inhabiting bacterium, Agrobacterium tumefaciens. The bacterium causes abnormal growths or galls on roots, twigs, and branches of euonymus and other shrubs primarily in the rose family. The bacterium stimulates the rapid growth of plant cells that results in the galls. In addition to being unsightly, the galls weaken and stunt the growth of the plant. Although galls can disrupt the flow of water and nutrients up the roots and branches, they usually do not cause total plant death. The disease can spread to other susceptible plants through contaminated soil and tools. Most chemical treatments are not effective.
The galls on forsythia, viburnum, highbush blueberry, American elm, hickory, maple, oak, and privet are believed to be caused by a fungus, Phomopsis sp. Since its cultural controls are the same as for bacterial crown gall, both are treated together herein. Chemical treatments, however, will differ. Chemical treatments for both are of very limited value to the home gardener. Only those relating to bacterial crown gall have been addressed.
Symptoms and Diagnosis
Galls are most commonly found near ground level on the roots and lower branches of the plants. As the galls enlarge, they become woody and hard. The outer layer turns brown and corky. The plant may be weakened and stunted with some branch or tip dieback. Symptoms may not develop immediately after infection. Galls grow most rapidly during the warm months of the year.
Life Cycle
Crown gall forming bacteria inhabit the soil and survive for many years. The bacterium can initially be brought in on the roots of infected plants. It then spreads by soil and water movement or contaminated pruning tools. Bacteria enter the plant through wounds possibly caused by chewing insects, cultivation damage, or from grafting and pruning tools. The crown gall bacterium has been known to survive more than two years in the soil in the absence of susceptible plants. It can live for several years in decomposing galls buried in the soil. Crown gall is likely to be more serious in limed soil than in acid soils so soil pH could be important in limiting the disease.
Integrated Pest Management Strategies
1. Prune out infected material. Crown gall cannot be eliminated from a shrub even though the infected plant may live for many years. To improve the appearance of the plant, prune out and destroy infected stems below the galled area. Sterilize the pruning shears after each cut with a mixture of one part bleach to nine parts water.
2. Destroy infected plants. Destroy the infected plant. The bacterium will remain in the soil so it is important to plant a resistant plant species. If the same species needs to be planted in the area, remove and replace the soil or consider soil sterilization.
3. Sterilize the soil. Soils known to be infected with crown gall bacteria can be sterilized using chemicals, heat, or antibiotics. This is not practical for most home gardeners. A biological control has been introduced using a bacterium, Agrobacterium radiobactor strain 84. This bacterium was discovered to be antagonistic to crown gall bacterium. It is available for use as a preplant treatment by dipping nursery stock in a suspension of the live bacteria in water.
4. Exclude the problem. When purchasing forsythia and euonymus plants, inspect them carefully for signs of galls. Do not purchase plants that show gall-forming symptoms.
5. Replant with a more resistant plant species. The following plants recommended by the University of Illinois show greater resistance to bacterial crown gall: barberry, hornbeam, true cedars, ginkgo, golden raintree, tulip tree, mahonia, spruce, linden, boxwood, catalpa, beech, holly, larch, magnolia, black gum, pine, Douglas fir, bald cypress, hemlock, birch, firethorn, redbud, smoke tree, sweet gum, deutzia, serviceberry, yellowwood, yew, and zelkova.
The galls on forsythia, viburnum, highbush blueberry, American elm, hickory, maple, oak, and privet are believed to be caused by a fungus, Phomopsis sp. Since its cultural controls are the same as for bacterial crown gall, both are treated together herein. Chemical treatments, however, will differ. Chemical treatments for both are of very limited value to the home gardener. Only those relating to bacterial crown gall have been addressed.
Symptoms and Diagnosis
Galls are most commonly found near ground level on the roots and lower branches of the plants. As the galls enlarge, they become woody and hard. The outer layer turns brown and corky. The plant may be weakened and stunted with some branch or tip dieback. Symptoms may not develop immediately after infection. Galls grow most rapidly during the warm months of the year.
Life Cycle
Crown gall forming bacteria inhabit the soil and survive for many years. The bacterium can initially be brought in on the roots of infected plants. It then spreads by soil and water movement or contaminated pruning tools. Bacteria enter the plant through wounds possibly caused by chewing insects, cultivation damage, or from grafting and pruning tools. The crown gall bacterium has been known to survive more than two years in the soil in the absence of susceptible plants. It can live for several years in decomposing galls buried in the soil. Crown gall is likely to be more serious in limed soil than in acid soils so soil pH could be important in limiting the disease.
Integrated Pest Management Strategies
1. Prune out infected material. Crown gall cannot be eliminated from a shrub even though the infected plant may live for many years. To improve the appearance of the plant, prune out and destroy infected stems below the galled area. Sterilize the pruning shears after each cut with a mixture of one part bleach to nine parts water.
2. Destroy infected plants. Destroy the infected plant. The bacterium will remain in the soil so it is important to plant a resistant plant species. If the same species needs to be planted in the area, remove and replace the soil or consider soil sterilization.
3. Sterilize the soil. Soils known to be infected with crown gall bacteria can be sterilized using chemicals, heat, or antibiotics. This is not practical for most home gardeners. A biological control has been introduced using a bacterium, Agrobacterium radiobactor strain 84. This bacterium was discovered to be antagonistic to crown gall bacterium. It is available for use as a preplant treatment by dipping nursery stock in a suspension of the live bacteria in water.
4. Exclude the problem. When purchasing forsythia and euonymus plants, inspect them carefully for signs of galls. Do not purchase plants that show gall-forming symptoms.
5. Replant with a more resistant plant species. The following plants recommended by the University of Illinois show greater resistance to bacterial crown gall: barberry, hornbeam, true cedars, ginkgo, golden raintree, tulip tree, mahonia, spruce, linden, boxwood, catalpa, beech, holly, larch, magnolia, black gum, pine, Douglas fir, bald cypress, hemlock, birch, firethorn, redbud, smoke tree, sweet gum, deutzia, serviceberry, yellowwood, yew, and zelkova.
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求助
cclecombe
2017年09月18日
I'm having a go at propergating succulents and im starting to wonder if the conservatory I'm keeping in them is getting too hot and drying the soil out too quickly. If I spray at 08:30 and my midday theyre bone dry again!
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sarajordan2993：@cclecombe - not a problem , anything i can do to help 😊
cclecombe：@sarajordan2993 Ah! Thank you so much! That's really helpful. I'll grab some different soil tomorrow and start over!
meriunkat：😅 the same thing is happening to mine, but don't worry they don't need to be wet too often when you begin propagating, only spray water after you see them growing roots so it won't rot right now.
sarajordan2993：do they already have roots ? it looks like they dont , but my eyes are horrible . firstly , dont water them until you start to notice roots . when they start to root , only water maybe 2 times per week . succulents dont like a lot of water as we all know , so cuttings wont be any different . i noticed also that you may have them in peat moss ?? if so , peat moss is very known for retaining moisture & squeezing the air out of the soil; therefore, creating an unhealthy environment for any type of plants . your best bet is to get a regular potting soil (miracle gro, etc) & mix equal parts of that with perlite & sand . ( 1 part soil , 1 part perlite , 1 part sand ) . i really hope this helped!
文章
Dummer. ゛☀
2017年09月17日
Mushrooms growing in lawns are common occurrences especially during rainy weather. They live off decaying organic matter in the soil, often decaying tree roots, and are not harmful to the lawn. They will naturally disappear as they age or they may be collected and composted, knocked down with a rake or hoe, or mowed over with your lawnmower. Mushrooms should never be collected and eaten unless you are expert in their identification. To the novice gardener, many poisonous mushrooms can look very similar to edible ones. Don’t take a chance.
Mushrooms that develop in a ring in the lawn are called fairy rings. They will be the focus of the remainder of this sheet.
Fairy rings are caused by many different soilinhabiting fungi of the class Basidiomycetes. These fungi can cause the development of rings or arcs of deep green grass as well as unthrifty or dead grass.
Fairy ring fungi do not attack grass directly, but break down organic matter in the soil. As a result, nitrogen is released which the grass uses, causing it to grow and develop a contrasting green ring. In cases where the mycelia of the fungus get very dense and inhibit water movement into the soil, grass in the arc may turn brown. Mycelia may also deplete soil nutrients and produce toxic levels of hydrogen cyanide. The mushrooms that appear after rainfall are the fruiting bodies of the fungus.
The organic matter fairy rings break down is often old tree stumps, roots, logs, lumber, and other larger pieces of organic material in the soil below the lawn. Once this material is depleted, the fairy ring will disappear. This may take considerable time. Several fairy rings may appear relatively close together, especially on lawns that exist on sites that were previously wooded areas. When this occurs, it becomes noticeable that fairy rings do not cross each other, as fungal activity ceases when fungi from different rings contact each other.
Symptoms and Diagnosis
Dark green circles, arcs, or rings of thick, fastgrowing grass develop anytime from green-up in the spring (most common) until the first hard frost in the fall. These rings are most commonly between 2 and 15 feet in diameter, although they may be larger or smaller. Mushrooms or puffballs may appear under wet conditions in the same ring pattern. In some cases, a ring of brown or dead grass may appear.
Life Cycle
Approximately 50 species of fungi are known to form fairy rings in turf, with Marasmius oreades, Agaricus campestris, Lycoperdon spp., and Scleroderma spp. being the most common. These fungi decompose organic debris in the soil and thatch.
Fairy ring starts from a piece of mycelium or spore at a single point feeding in the thatch layer or on soil organic matter. The uniform outward growth of the fungus results in the development of rings.
Under certain conditions, and with certain fairy ring fungi, a ring of dead grass develops. Some of the responsible fungi have been shown to penetrate and kill root cells resulting in dead rings of grass. In addition, the mycelia of some fairy ring fungi are reported to be hydrophobic, creating a waterimpervious layer resulting in drought-stress problems for the grass. Once the soil under this mycelial layer becomes dry, it is very difficult to wet, and the roots of the grass plant die.
Integrated Pest Management Strategies
1. Fertilizer. Use of a nitrogen fertilizer can mask the symptoms of fairy ring by causing the rest of the lawn to green up. Using a soil needle (deep root feeder) to aerate and irrigate dead and dying rings is recommended.
2. Removal. Fairy ring development can be traced to buried organic debris. Undecomposed tree roots, wood scraps from construction projects, and other organic debris are commonly colonized by the fairy ring fungi and should be removed before establishing a new lawn. Use clean, ring-free sod for a new or renovated lawn.
Destroying existing turf may be required in persistent cases. Discard or kill a strip of sod 1 to 2 feet wide on each side of the zone of lush turf with a non-selective herbicide. Cultivate the area repeatedly to thoroughly mix the ring and nonring soil. Eliminate dry spots by soaking the cultivated area with water. Reseed or install clean, ring-free sod.
3. Thatch. Eliminate thatch buildup with a dethatching program.
4. Fungicides. Some fungicides are available for suppression of fairy ring, however, they may be only temporary as the decaying material may still be present.
Organic Strategies
Strategies 2 and 3 are strictly organic approaches. Using an appropriate organic fertilizer would be a viable organic approach to Strategy 1.
Mushrooms that develop in a ring in the lawn are called fairy rings. They will be the focus of the remainder of this sheet.
Fairy rings are caused by many different soilinhabiting fungi of the class Basidiomycetes. These fungi can cause the development of rings or arcs of deep green grass as well as unthrifty or dead grass.
Fairy ring fungi do not attack grass directly, but break down organic matter in the soil. As a result, nitrogen is released which the grass uses, causing it to grow and develop a contrasting green ring. In cases where the mycelia of the fungus get very dense and inhibit water movement into the soil, grass in the arc may turn brown. Mycelia may also deplete soil nutrients and produce toxic levels of hydrogen cyanide. The mushrooms that appear after rainfall are the fruiting bodies of the fungus.
The organic matter fairy rings break down is often old tree stumps, roots, logs, lumber, and other larger pieces of organic material in the soil below the lawn. Once this material is depleted, the fairy ring will disappear. This may take considerable time. Several fairy rings may appear relatively close together, especially on lawns that exist on sites that were previously wooded areas. When this occurs, it becomes noticeable that fairy rings do not cross each other, as fungal activity ceases when fungi from different rings contact each other.
Symptoms and Diagnosis
Dark green circles, arcs, or rings of thick, fastgrowing grass develop anytime from green-up in the spring (most common) until the first hard frost in the fall. These rings are most commonly between 2 and 15 feet in diameter, although they may be larger or smaller. Mushrooms or puffballs may appear under wet conditions in the same ring pattern. In some cases, a ring of brown or dead grass may appear.
Life Cycle
Approximately 50 species of fungi are known to form fairy rings in turf, with Marasmius oreades, Agaricus campestris, Lycoperdon spp., and Scleroderma spp. being the most common. These fungi decompose organic debris in the soil and thatch.
Fairy ring starts from a piece of mycelium or spore at a single point feeding in the thatch layer or on soil organic matter. The uniform outward growth of the fungus results in the development of rings.
Under certain conditions, and with certain fairy ring fungi, a ring of dead grass develops. Some of the responsible fungi have been shown to penetrate and kill root cells resulting in dead rings of grass. In addition, the mycelia of some fairy ring fungi are reported to be hydrophobic, creating a waterimpervious layer resulting in drought-stress problems for the grass. Once the soil under this mycelial layer becomes dry, it is very difficult to wet, and the roots of the grass plant die.
Integrated Pest Management Strategies
1. Fertilizer. Use of a nitrogen fertilizer can mask the symptoms of fairy ring by causing the rest of the lawn to green up. Using a soil needle (deep root feeder) to aerate and irrigate dead and dying rings is recommended.
2. Removal. Fairy ring development can be traced to buried organic debris. Undecomposed tree roots, wood scraps from construction projects, and other organic debris are commonly colonized by the fairy ring fungi and should be removed before establishing a new lawn. Use clean, ring-free sod for a new or renovated lawn.
Destroying existing turf may be required in persistent cases. Discard or kill a strip of sod 1 to 2 feet wide on each side of the zone of lush turf with a non-selective herbicide. Cultivate the area repeatedly to thoroughly mix the ring and nonring soil. Eliminate dry spots by soaking the cultivated area with water. Reseed or install clean, ring-free sod.
3. Thatch. Eliminate thatch buildup with a dethatching program.
4. Fungicides. Some fungicides are available for suppression of fairy ring, however, they may be only temporary as the decaying material may still be present.
Organic Strategies
Strategies 2 and 3 are strictly organic approaches. Using an appropriate organic fertilizer would be a viable organic approach to Strategy 1.
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文章
Dummer. ゛☀
2017年09月17日
Many ornamental trees and shrubs are susceptible to Phytophthora root rot and can develop root and crown rot, particularly if the soil around the base of the plant remains wet for long periods of time. Typical symptoms of a root disease are apparent on infected plants. The leaves will appear droughtstressed and may die quickly as the weather warms in late spring or early summer. Trees that are especially susceptible include oak and dogwood.
Symptoms and Diagnosis
Leaves will appear drought stressed, sometimes turning dull green, yellow, red, or purple as they wilt. Infected trees may survive a few years before the disease kills the whole plant. The bark around the soil-line may appear darkened. Cutting away some bark should reveal red-brown discoloration in the wood underneath it. Disease symptoms are distinguishable from Armillaria root rot because mycelial mats do not develop in tissues infected with Phytophthora root rot.
Life Cycle
Root rot-causing Phytophthora species can survive in the soil for years, as long as moist conditions persist. It can spread through splashing rain, irrigation water, and runoff water. Disease fungi can spread through contaminated soil and garden equipment as well. Rot is more likely to spread in early spring and late fall during cool, rainy weather. But symptoms are more likely during stress periods of low rainfall. Flooded and saturated soil conditions for 6–8 hours are especially conducive to the spread of root rots. Wounds are not required for infection.
Integrated Pest Management Strategies
1. Improve water drainage. Prior to planting, make amendments to the soil composition to help manage drainage away from tree roots. Don’t allow water to pool around the collar or root system. Core aerate to improve drainage and lessen compaction.
2. Raise the planting site to avoid poor drainage and prevent pools of standing water from forming around valuable ornamentals. Plant on mounds of soil. Never plant trees deeper than they were planted at the nursery.
3. Separate plants, shrubs, and trees according to their irrigation needs, and avoid overwatering.
4. Remove soil. If soil has been piled up over the crown, remove it carefully to expose root flare. This is where fungal infection is likely to occur.
5. Plant resistant or less susceptible varieties. Consider replanting with tolerant plants after Phytophthora root rot has been diagnosed. Trees that are tolerant to Phytophthora root rot include white cedar and American arborvitae.
Symptoms and Diagnosis
Leaves will appear drought stressed, sometimes turning dull green, yellow, red, or purple as they wilt. Infected trees may survive a few years before the disease kills the whole plant. The bark around the soil-line may appear darkened. Cutting away some bark should reveal red-brown discoloration in the wood underneath it. Disease symptoms are distinguishable from Armillaria root rot because mycelial mats do not develop in tissues infected with Phytophthora root rot.
Life Cycle
Root rot-causing Phytophthora species can survive in the soil for years, as long as moist conditions persist. It can spread through splashing rain, irrigation water, and runoff water. Disease fungi can spread through contaminated soil and garden equipment as well. Rot is more likely to spread in early spring and late fall during cool, rainy weather. But symptoms are more likely during stress periods of low rainfall. Flooded and saturated soil conditions for 6–8 hours are especially conducive to the spread of root rots. Wounds are not required for infection.
Integrated Pest Management Strategies
1. Improve water drainage. Prior to planting, make amendments to the soil composition to help manage drainage away from tree roots. Don’t allow water to pool around the collar or root system. Core aerate to improve drainage and lessen compaction.
2. Raise the planting site to avoid poor drainage and prevent pools of standing water from forming around valuable ornamentals. Plant on mounds of soil. Never plant trees deeper than they were planted at the nursery.
3. Separate plants, shrubs, and trees according to their irrigation needs, and avoid overwatering.
4. Remove soil. If soil has been piled up over the crown, remove it carefully to expose root flare. This is where fungal infection is likely to occur.
5. Plant resistant or less susceptible varieties. Consider replanting with tolerant plants after Phytophthora root rot has been diagnosed. Trees that are tolerant to Phytophthora root rot include white cedar and American arborvitae.
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文章
Dummer. ゛☀
2017年09月16日
This creeping juniper (Juniperus) died from overwatering
Overwatering is one of the more common causes of plant problem. Heavy and poorly drained soils are susceptible to becoming waterlogged. Roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. The longer the air is cut off, the greater the root damage. The dying roots decay and cannot supply the plants with nutrients and water. Damage caused by over watering is frequently misdiagnosed as pest damage. However, pest damage rarely causes roots to concentrate near the surface of the soil. Plants stressed or injured by waterlogging can become abnormally susceptible to certain fungal pathogens. Phytophthora spp. for example, cause root rot most often in soils that are periodically waterlogged.
Symptoms and Diagnosis
Plants growing in soil that is too wet suffer from a lack of oxygen which leads to the death of roots and a loss of vigor in the plant. Stunted slow growth with yellowing leaves is a symptom of over watering. Plants may suffer from leaf scorch or leaf burn. Water soaked spots and blisters (Oedema) may appear on stems and leaves. The crown of the plant may rot. Damaged roots have little defense against the entrance of rot causing soil organisms. And so the plant dies of root rot.
Integrated Pest Management Strategies
1. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease. Also make sure you don't have leaking irrigation pipes or downspouts that are keeping the soil too wet in a location.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---organic matter can improve drainage in heavy clay soils. Take care to keep mulch away from stems.
4. Use appropriate plants. Evaluate your site for new plantings. Choose plants with the appropriate water and cultural needs that will thrive on your site. Use water loving plants for moist poorly drained soils. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary. Most plants will normally wilt in hot sun and may recover on their own later in the day as the sun moves. Make sure soil is not too wet based on the needs of particular plants before watering; you may end up by over watering.
6. A dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture. Check for overwatering by digging into root zone or knocking a small potted plant out of its container. Soil that has been too long without oxygen usually smells sour or rotten.
7. Give priority to watering newly planted trees and shrubs. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Remember that when plants are fully established, they will require less water.
Overwatering is one of the more common causes of plant problem. Heavy and poorly drained soils are susceptible to becoming waterlogged. Roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. The longer the air is cut off, the greater the root damage. The dying roots decay and cannot supply the plants with nutrients and water. Damage caused by over watering is frequently misdiagnosed as pest damage. However, pest damage rarely causes roots to concentrate near the surface of the soil. Plants stressed or injured by waterlogging can become abnormally susceptible to certain fungal pathogens. Phytophthora spp. for example, cause root rot most often in soils that are periodically waterlogged.
Symptoms and Diagnosis
Plants growing in soil that is too wet suffer from a lack of oxygen which leads to the death of roots and a loss of vigor in the plant. Stunted slow growth with yellowing leaves is a symptom of over watering. Plants may suffer from leaf scorch or leaf burn. Water soaked spots and blisters (Oedema) may appear on stems and leaves. The crown of the plant may rot. Damaged roots have little defense against the entrance of rot causing soil organisms. And so the plant dies of root rot.
Integrated Pest Management Strategies
1. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease. Also make sure you don't have leaking irrigation pipes or downspouts that are keeping the soil too wet in a location.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---organic matter can improve drainage in heavy clay soils. Take care to keep mulch away from stems.
4. Use appropriate plants. Evaluate your site for new plantings. Choose plants with the appropriate water and cultural needs that will thrive on your site. Use water loving plants for moist poorly drained soils. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary. Most plants will normally wilt in hot sun and may recover on their own later in the day as the sun moves. Make sure soil is not too wet based on the needs of particular plants before watering; you may end up by over watering.
6. A dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture. Check for overwatering by digging into root zone or knocking a small potted plant out of its container. Soil that has been too long without oxygen usually smells sour or rotten.
7. Give priority to watering newly planted trees and shrubs. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Remember that when plants are fully established, they will require less water.
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文章
Dummer. ゛☀
2017年09月16日
Herbicide damage can be hard to diagnose. A trained individual can generally tell when damage from an herbicide is a possible cause, but validation requires a laboratory test of the plant tissue and/or the soil while the chemical is still present. Such tests can cost between $65 and $150 per sample or more. Individual tests need to be made for each suspected herbicide. Testing may not be available for some herbicides. More commonly, a circumstantial case is made after a thorough examination of the damaged plant(s), surrounding plants, the pattern of damage, the likelihood of damage occurring given the suspected point of herbicide application, and the history of the symptoms.
Symptoms and Diagnosis
General symptoms can include one or more of the following symptoms: curling or cupped leaves, stunted growth, discolored leaves, or leaves with dead spots. The same herbicide may cause different symptoms on different plant species.
Since herbicides do not leave a "calling card" like mites, insects, and diseases (but the damage they cause can be mistaken for herbicide damage), it is advised to rule these out first. Other disorders that produce symptoms that can resemble herbicide damage include virus diseases, adverse weather, salt damage, drought, soil compaction, misapplied fertilizers, root stress, and nutrient deficiencies. Excluding these as causes requires close examination of the site and attention to patterns. Is the pattern of damaged plants consistent with drifting spray? Is more than just one kind of plant affected? Did the symptoms appear within one or two days (in most cases) of the suspected application of an herbicide? Were any lawn weed control products used in the area, including weed and feed products containing an herbicide? The answer to these and other questions can help make a circumstantial case of herbicide damage.
Recovery Prognosis
Recovery of plants damaged by herbicides is dependent upon many factors including amount of initial damage incurred as well as what herbicide caused the damage. Trees and shrubs that receive minor damage from a broadleaf herbicide such as 2,4-D are likely to recover or have only minor damage. Trees and shrubs that have been damaged by dicamba which was applied to a lawn area and then was washed down into the root system of trees and shrubs can show damage for several years as they gradually recover. Plants damaged by soil sterilant herbicides are the least likely to recover.
Plants that show signs of growing out of the problem will likely recover. Plants that appear to lose vigor may not. The survival of damaged plants can be increased by reducing other stresses. Water during dry periods, fertilize according to a soil test report to increase vigor, and watch for and control any insect or disease problems.
Symptoms and Diagnosis
General symptoms can include one or more of the following symptoms: curling or cupped leaves, stunted growth, discolored leaves, or leaves with dead spots. The same herbicide may cause different symptoms on different plant species.
Since herbicides do not leave a "calling card" like mites, insects, and diseases (but the damage they cause can be mistaken for herbicide damage), it is advised to rule these out first. Other disorders that produce symptoms that can resemble herbicide damage include virus diseases, adverse weather, salt damage, drought, soil compaction, misapplied fertilizers, root stress, and nutrient deficiencies. Excluding these as causes requires close examination of the site and attention to patterns. Is the pattern of damaged plants consistent with drifting spray? Is more than just one kind of plant affected? Did the symptoms appear within one or two days (in most cases) of the suspected application of an herbicide? Were any lawn weed control products used in the area, including weed and feed products containing an herbicide? The answer to these and other questions can help make a circumstantial case of herbicide damage.
Recovery Prognosis
Recovery of plants damaged by herbicides is dependent upon many factors including amount of initial damage incurred as well as what herbicide caused the damage. Trees and shrubs that receive minor damage from a broadleaf herbicide such as 2,4-D are likely to recover or have only minor damage. Trees and shrubs that have been damaged by dicamba which was applied to a lawn area and then was washed down into the root system of trees and shrubs can show damage for several years as they gradually recover. Plants damaged by soil sterilant herbicides are the least likely to recover.
Plants that show signs of growing out of the problem will likely recover. Plants that appear to lose vigor may not. The survival of damaged plants can be increased by reducing other stresses. Water during dry periods, fertilize according to a soil test report to increase vigor, and watch for and control any insect or disease problems.
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文章
Dummer. ゛☀
2017年09月16日
The water needs of different plants vary greatly. Some factors to consider include the species and age of the plant, the type of soil in which it is planted, and its exposure. The symptoms of drought stress may be similar to the symptoms of over watering or even to some pest and disease problems. It is important to identify the causes of the problem in order to take corrective steps.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
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文章
Dummer. ゛☀
2017年09月16日
Sclerotia of southern blight (resembling mustard seeds) at the crown of Japanese anemone (Anemone)
Crown rot, sometimes called southern blight or southern stem rot, is caused by several soil-borne fungi. It affects herbaceous plants and some woody plants but is most commonly found on ajuga, anemone, campanula, chrysanthemum, delphinium, hosta, hydrangea, iris, narcissus, phlox, rudbeckia, scabiosa, sedum, and tulip. The problem generally requires removal of the diseased plant.
Symptoms and Diagnosis
Crown rot causes deterioration and rotting of the tissues at the crown of the plant causing the leaves to turn yellow, collapse, and die. When the temperature exceeds 70 degrees F, infected plants develop discolored, water-soaked stem lesions near the soil line. During periods of high humidity, coarse cottony webbing (mycelium) develops and fans out over the stem base and surrounding soil. Sclerotia, which resemble mustard seeds and vary from white to reddish tan to light brown in color, develop at the base of the plant. Enough sclerotia may form to create a crust on the soil.
Life Cycle
The fungi which cause crown rot (Pellicularia rolfsii, Sclerotium delphinii, and Sclerotium rolfsii) survive in the soil and are spread by flowing water, transported or contaminated soil, transplants, and tools. Conditions of 86–95 degrees F for several days with intermittent rains are conducive for fungal development.
Integrated Pest Management Strategies
1. Remove diseased plants as soon as they are noticed. Plants can be buried, but do NOT place them in your compost pile.
2. Excavate surrounding soil. Dig out and replace the soil to a depth of 8 inches and 6 inches beyond the diseased area.
3. Solarize the soil. If you do not remove the soil and the area receives at least two to three hours of direct sun, solarize it. Cover the area with clear plastic and leave it for two to three months in the heat of the summer.
4. Provide better drainage. Increasing the organic content of the soil and improving drainage will make the environment less desirable to the fungus.
5. Sterilize all tools. Clean all tools used in digging with a solution of 1–part bleach to 9–parts water to disinfect the tools and reduce spreading the disease to other locations in your garden.
6. Try fungicides. Pesticides registered for control of crown rot include mancozeb and thiophanate methyl (Cleary 3336).
Crown rot, sometimes called southern blight or southern stem rot, is caused by several soil-borne fungi. It affects herbaceous plants and some woody plants but is most commonly found on ajuga, anemone, campanula, chrysanthemum, delphinium, hosta, hydrangea, iris, narcissus, phlox, rudbeckia, scabiosa, sedum, and tulip. The problem generally requires removal of the diseased plant.
Symptoms and Diagnosis
Crown rot causes deterioration and rotting of the tissues at the crown of the plant causing the leaves to turn yellow, collapse, and die. When the temperature exceeds 70 degrees F, infected plants develop discolored, water-soaked stem lesions near the soil line. During periods of high humidity, coarse cottony webbing (mycelium) develops and fans out over the stem base and surrounding soil. Sclerotia, which resemble mustard seeds and vary from white to reddish tan to light brown in color, develop at the base of the plant. Enough sclerotia may form to create a crust on the soil.
Life Cycle
The fungi which cause crown rot (Pellicularia rolfsii, Sclerotium delphinii, and Sclerotium rolfsii) survive in the soil and are spread by flowing water, transported or contaminated soil, transplants, and tools. Conditions of 86–95 degrees F for several days with intermittent rains are conducive for fungal development.
Integrated Pest Management Strategies
1. Remove diseased plants as soon as they are noticed. Plants can be buried, but do NOT place them in your compost pile.
2. Excavate surrounding soil. Dig out and replace the soil to a depth of 8 inches and 6 inches beyond the diseased area.
3. Solarize the soil. If you do not remove the soil and the area receives at least two to three hours of direct sun, solarize it. Cover the area with clear plastic and leave it for two to three months in the heat of the summer.
4. Provide better drainage. Increasing the organic content of the soil and improving drainage will make the environment less desirable to the fungus.
5. Sterilize all tools. Clean all tools used in digging with a solution of 1–part bleach to 9–parts water to disinfect the tools and reduce spreading the disease to other locations in your garden.
6. Try fungicides. Pesticides registered for control of crown rot include mancozeb and thiophanate methyl (Cleary 3336).
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文章
Dummer. ゛☀
2017年09月15日
Wilting plant leaves, sagging stems, and aborting flowers and fruits. Dry soil, especially where new plants have not had a chance to put down deep roots. Dry compost in pots and hanging baskets, and pots blowing over.
Plants affected
All plants are affected.
About Wilting through lack of water
Plants have a vascular system which enables water and nutrients to be taken from the environment through a complex root system.
The continual flow of water and nutrients ensures that the vascular system remains firm, and that the plant continues to grow in a healthy way.
Lack of water results in a loss of firmness which causes the symptoms of wilting.
Plants respond to lack of water by closing down areas of the vascular system, which consequently results in leaf, flower and fruit loss.
Plants can usually recover from short periods of lack of water, but sustained periods of drought often result in death.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Wilting through lack of water
There is no chemical control available for this problem.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Water wilted plants as soon as possible.
Plunge pots with very wilted plants into a bucket of water for an hour or so.
After plunging or watering, place pots with wilted plants in the shade to recover, and consider moving them to a shady spot permanently.
Move wilted plants out of windy spots, and avoid putting them back in the same place.
If the problem is affecting plants in the greenhouse, after watering them, damp down the floor with a hose or watering can.
Prevention
Regularly monitor plants for wilting symptoms.
Design a watering schedule for plants based on their individual needs. As a general guide, pots need watering once a day, hanging baskets twice a day, new plants in the border need careful monitoring in their first year and will probably need watering two or three times a week. Established border plants will have deeper roots and will benefit most from one long drink each week rather than a daily dose.
For potted and hanging basket plants, water-retaining gel granules can be used in the compost.
The base of the pot or basket can also be lined with a plastic bag to help retain water. If lining a pot, make a few small holes in the bag with a kitchen fork so the compost does not get waterlogged.
Avoid planting delicate plants in locations of intense sunlight, or strong winds.
During summer use shading to protect greenhouse crops.
Incorporating mulch and organic material into the soil improves its water retention.
Plants affected
All plants are affected.
About Wilting through lack of water
Plants have a vascular system which enables water and nutrients to be taken from the environment through a complex root system.
The continual flow of water and nutrients ensures that the vascular system remains firm, and that the plant continues to grow in a healthy way.
Lack of water results in a loss of firmness which causes the symptoms of wilting.
Plants respond to lack of water by closing down areas of the vascular system, which consequently results in leaf, flower and fruit loss.
Plants can usually recover from short periods of lack of water, but sustained periods of drought often result in death.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Wilting through lack of water
There is no chemical control available for this problem.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Water wilted plants as soon as possible.
Plunge pots with very wilted plants into a bucket of water for an hour or so.
After plunging or watering, place pots with wilted plants in the shade to recover, and consider moving them to a shady spot permanently.
Move wilted plants out of windy spots, and avoid putting them back in the same place.
If the problem is affecting plants in the greenhouse, after watering them, damp down the floor with a hose or watering can.
Prevention
Regularly monitor plants for wilting symptoms.
Design a watering schedule for plants based on their individual needs. As a general guide, pots need watering once a day, hanging baskets twice a day, new plants in the border need careful monitoring in their first year and will probably need watering two or three times a week. Established border plants will have deeper roots and will benefit most from one long drink each week rather than a daily dose.
For potted and hanging basket plants, water-retaining gel granules can be used in the compost.
The base of the pot or basket can also be lined with a plastic bag to help retain water. If lining a pot, make a few small holes in the bag with a kitchen fork so the compost does not get waterlogged.
Avoid planting delicate plants in locations of intense sunlight, or strong winds.
During summer use shading to protect greenhouse crops.
Incorporating mulch and organic material into the soil improves its water retention.
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