Due to the prevalence of pathogens, nutrient deficits, and insect invasions, one of the most important aspects of forestry is fighting tree diseases. The forest products sector would feel the effects if tree health is compromised.
Pests and diseases in trees are a major problem for every industry that relies on them, from harvesting to environmental concerns. In addition, a healthy forest indicates a healthy populace; therefore, the general public also benefits. In this sense, foresters’ routine work of identifying and treating tree diseases is something everyone can profit from.
Typical Tree Illnesses and Their Remedies
Anthracnose
Sycamore, ash, and oak trees are particularly vulnerable to anthracnose because they are deciduous. The effects extend to shrubs like privet. Leaves, stems, blooms, and fruits develop unsightly black, sunken lesions.
Anthracnose is more common in the spring because the fungus that causes it needs water to grow and infect new plants. Anthracnose is more of a cosmetic issue than a serious threat to tree health; hence, it is rarely treated. Raking leaves and pruning diseased branches in the fall and winter can help reduce the population of this insect. If you water and fertilise your trees properly, they will thrive and quickly cover the ground.
Anthracnose is a widespread disease that can infect hardwood trees. Dead patches or flaws on the leaves are the most obvious indication of this group of diseases. Some of the most susceptible tree species include the American sycamore, black walnut, dogwood, and white oak.
Cities are particularly vulnerable to anthrax’s deadly effects. Due to the death or removal of shade trees, property values have dropped.
Treatment:
- Cut down and dispose of diseased limbs
- Watering and fertilising trees properly can lower risks and boost tree health.
- When outbreaks occur, use fungicides.
Apple Scab
Choose a variety that can withstand apple scab if you want to grow apples. To find apple cultivars well suited to your area that are also resistant to scab, contact your county’s cooperative extension service. Raking and getting rid of leaves before winter can help reduce the occurrence of apple scabs in subsequent years. Apple scab cannot be treated on infected trees but can be prevented on healthy trees using fungicides. Having the right timing is essential.
This fungal disease does, in fact, attack apple trees. Dark, scaly sores appear on branches, leaves, and fruit and cause them to rot. The spores that cause apple scab overwinter in decomposing fruit and leaves.
Treatment
- Rake and remove dead leaves and fruit to lessen the number of spores that can survive the winter.
- Use fungicides to prevent damage to young plants during the growing season.
Canker Diseases
Cytospora canker attacks pines, poplars, spruces, and willows, one of many canker diseases that attack trees. When bark or sapwood is damaged, fungi or bacteria can invade, causing a condition known as canker. Over time, the tree’s vascular system becomes congested, cutting off its water supply and nutrients. Branches may perish if this obstruction occurs near the canker. The entire tree could perish if it becomes entangled in the cord.
Stressed trees, whether from the elements, animal browsing, human intervention, etc., are the most at risk. You can prevent your trees from canker by pruning off infected branches, maintaining your trees properly, and providing them with winter protection. Between each cut, disinfect the pruners in a 10% bleach solution.
Treatment
- Between each cut, disinfect all the pruning and cutting instruments with rubbing alcohol at a concentration of 70% or a solution composed of one part household bleach to ten parts water.
- Avoid spreading the disease by only working while the bark is dry.
- Remove canker-affected portions of stems and twigs, leaving a few inches of healthy growth.
- Canked branches near the trunk should be clipped down to the collar; no stubs are allowed.
- Never try to remove a canker by cutting into it. Doing so would help the disease spread.
- If a canker appears on a tree’s trunk, you shouldn’t try to remove it. Consult an arborist for assistance in such situations.
Cedar-Apple Rust
As its name implies, the cedar-apple rust fungus requires cedar for its survival. The hawthorn tree is subject to cedar-hawthorn rust, a type of fungus.
During the cedar’s first year, the fungus feeds on it. The spores overwinter on the first host, and the following spring, the wind blows them to the second host, typically within a few hundred feet but up to a mile away.
Large fruiting bodies form on stunted branches, and the disease causes vivid yellow-orange streaks on the leaves and berries. Potential for early leaf and fruit drop. One method of cultural control that can be implemented is planting a variety resistant to cedar-apple rust (for guidance, get in touch with your local cooperative extension). Alternatively, you might use a fungicide in the spring to prevent issues. You’ll need to make multiple submissions.
Treatment
- To reduce spore generation, cedar galls must be removed from trees.
- When outbreaks occur, use fungicides.
- Pick apple trees that can withstand disease.
Diplodia Tip Blight
Many tree diseases, including blight, target stressed conifers like the Austrian pine. The result is stunted, discoloured, and ultimately dead new growth. Mulch and water your trees regularly, especially during dry months, to lessen the chance of diplodia tip blight. Remove and discard sick cones and branch tips, and disinfect pruning shears with rubbing alcohol or a bleach solution before each cut. Fungicides are applied greatly in the spring: once when the buds open, once when the new shoots are halfway out of the ground, and once when they are well-established.
Treatment
- Remove and discard diseased branches.
- Fungicides should be used during epidemics.
Dothistroma Needle Blight
The browning of the needle tips is a symptom of this disease in pine trees. The tip of the needle gradually becomes brown and breaks off. The needle blight caused by Dothistroma is typically found on Austrian and Ponderosa pines and can be lethal. Mulching and watering trees from below rather than spraying the leaves are also effective preventative methods. Another option is to use a fungicide.
Treatment
- Any trees that have less than 15% of the crown damaged (at the time of assessment in the winter) should be sprayed with copper fungicides in the early summer.
Fire Blight
Leaves that droop and turn black and branches that look like they’ve been charred in a fire are classic symptoms of fire blight. Due to the sporadic nature of fire blight infection, patches of dead leaves may appear anywhere on the plant. Humid, warm areas are ideal for its growth. Infected branches can be cut down to healthy wood and destroyed to control fire blight. Clean your pruning tools in a 10% bleach solution between each cut. Fruit trees are particularly vulnerable to fire blight, but there are steps you can take to preserve them.
Fruit trees like apples, pears, cherries, and hawthorns are all vulnerable to this bacterium. Cankers and darkened, wilting shoots should be looked for.
Treatment
- Remove affected limbs to a depth of 12 to 18 inches below the disease’s surface.
- Use bactericides while flowers are out. Adequate watering and fertilisation can reduce risk (and boost tree health).
Oak Wilt
As a fungal disease, oak wilt only affects oak trees. Species belonging to the red oak group (those with pointed leaf lobes) are particularly vulnerable, but those belonging to the white oak family (those with rounded leaf lobes) are less so. The tree’s leaves begin to brown and wilt from the top down. Oak wilt can be transmitted from one tree to another through its roots or by sap-sucking beetles drawn to freshly cut wood. During the growing season, oak trees should not be pruned. When pruning an oak tree during the growing season, it is recommended to use a tree wound sealant to prevent beetles from entering the wound. If you take good care of your oak trees, they will provide gorgeous fall leaves.
Treatment
- It is necessary to uproot and remove infected trees to stop the spread of oak wilt.
- It’s best if healthy and sick trees aren’t grafted together at the root.
- Fungicide injections can be used to protect healthy trees.
Powdery Mildew
Infected plants will have a white powdery coating, making powdery mildew easy to spot. The wilting, yellowing, and premature falling off of the leaves is a natural consequence of time passing. This fungus favours damp, low-rain conditions and thrives on plants in the shade.
Plants like crape myrtle and lilac are prone to this pest, so it’s best to avoid them and go with resistant types. Air out the plants you already have. A fungicide can be applied to plants to prevent disease.
Treatment
- The best course of action would be to remove and destroy all contaminated plants, which is impractical. Few gardeners are prepared to risk losing their peonies or squash when powdery mildew strikes. Fortunately, more humane ways exist to eliminate these annoying mushrooms in your yard.
Phytophthora Root Rot
Root rot due to fungal decay Phytophthora infects plants that have poor drainage. Due to drought stress, the leaves on the trees appear drooping and have taken on a pale green or yellow hue. There is no treatment for root rot, but it can be prevented. Avoid planting trees near gutters or in low-lying, wet areas. You can also plant trees like bald cypress, willow, sycamore, and black gum that do well in damp areas. Trees should not be planted any deeper than in the nursery; instead, they should be planted at the same level or slightly higher.
Treatment
Cut Down Diseased Trees and Cut Down Infected Plants
Once the tree, shrub, or plant’s contamination has been confirmed, it must be cut down and disposed of safely.
Raise Drainage Rates
Soil drainage is a crucial measure in the fight against Phytophthora. Nonetheless, extended wet periods may make issues like standing water or saturation inevitable. Loam soil, a mix of sand, clay, and silt, is called “perfect soil” because it holds water and nutrients, is well-aerated, and drains excess water to prevent illness.
Soil Testing
Regularly checking the soil’s pH and nutrient levels will help keep your plants and trees in the best shape possible. If your trees and plants are in good health, they will be more resistant to opportunistic diseases.
Hydrogen Peroxide
Soil infections and illnesses like Phytophthora can be effectively eradicated by applying a 3% solution of household hydrogen peroxide. Allow the peroxide-water solution to soak into the soil before rinsing as usual.
No Mulching or Composting
If you remove a diseased part of a specimen, don’t put it in a compost pile or mulching system where it can infect other plants.
Plant Disease Resistant Species
Root rot is a common problem in locations that have experienced Phytophthora infestations. Thus, choosing shrub, plant, or tree species resistant to the fungus is important.
Additional Advice on Tree Maintenance
A healthy tree is less likely to become infected; therefore, properly caring for your trees can go a long way towards preserving them. Pruning with the appropriate technique and at the right time (a hint: winter is good for pruning, as trees are dormant) is also essential to tree maintenance.
You need help identifying that tree. The right care can only be given if the patient is properly identified. Talk to an arborist if you want detailed advice on caring for your trees.
Leaf wilt, leaf spots, cankers, and other indicators of illness are not necessarily fatal to a tree if caught early enough. Maintain a routine of checking on your trees every time you water. If you see something unusual with trees, you should consult a professional.
Conclusion
In the forestry industry, common tree illnesses are a big problem because they are caused by pathogens, lack of nutrients, and insect infestations. These diseases have an impact on many fields, such as farming and environmental issues. Everyone gains from the work that foresters do every day to find and treat these diseases.
A lot of deciduous trees, like sycamore, ash, and oak, get anthracnose, a disease that makes leaves, stems, flowers, and seeds look ugly with black, sunken spots. In the fall and winter, raking leaves and cutting off diseased trees can help lower the number of these bugs. When you water and fertilise trees the right way, you lower their risks and improve their health.
You can treat apple scab by picking a type of tree that can handle it, raking and removing leaves before winter, and using fungicides to keep young plants from getting hurt during the growing season. Pines, poplars, spruces, and willows are all affected by canker diseases, which clog up the trees’ circulatory systems and may kill them. To stop cankers, cut off any infected stems, take good care of your trees, and protect them from the winter.
Cedar-apple rust is a kind of fungus that can’t live without cedar. It makes stems grow short and fruiting bodies that are big. It also gives leaves and berries bright yellow-orange stripes. Some cultural ways to get rid of cedar-apple rust are to plant a type that is resistant to it or to use fungicides in the spring.
Diplodia tip blight attacks stressed conifers like the Austrian pine and make new growth that is short, discoloured and dies. Diplodia tip blight is less likely to happen if you mulch, water, and clean your trimming shears regularly.
This is a disease called Dothistroma Needle Blight that turns the tips of pine needles brown. It can kill the trees. Copper fungicides can be used in early summer to treat it on Austrian and Ponderosa pines, where it is most common. Fire Blight is a fungal disease that can be spread by bugs or roots. It makes fruit trees’ leaves droop and turn black. This bacterium is especially dangerous to fruit trees. To treat it, you have to cut off any damaged branches and use bactericides while the flowers are still blooming.
A fungus called oak wilt attacks oak trees, and red oak is especially likely to get it. To stop the disease from spreading, affected trees need to be cut down and thrown away. Powdery mildew is another fungal disease that makes plants wilt, turn yellow, and lose their leaves early. Avoid plants like crape myrtle and lilac and choose ones that are more hardy.
Phytophthora Root Rot is a fungal rot that affects plants that don’t have good drainage and makes the leaves droop. It can be stopped by planting trees near gutters or in wet, low-lying places. Testing the earth and using hydrogen peroxide on a regular basis can help people stay healthy and lower their risk of getting sick.
Root rot can be avoided by choosing plant types that are not easily damaged by disease. For trees to last, they need to be properly cared for, which includes trimming with the right tools and at the right time. It’s important to find signs of illness early on, and checking on trees on a daily basis can help stop more damage.
Content Summary
- Combatting tree diseases is essential for forestry due to pathogens and nutrient deficits.
- Tree health directly impacts the forest products sector.
- Industries reliant on trees face major challenges from pests and diseases.
- A healthy forest signifies a healthy populace, benefiting everyone.
- Foresters regularly identify and treat tree diseases for community benefit.
- Anthracnose commonly affects sycamore, ash, and oak trees.
- Sunken lesions are symptoms of Anthracnose on leaves and fruits.
- Wet conditions in spring promote Anthracnose spread.
- Proper watering and fertilisation can help trees resist Anthracnose.
- Anthracnose can lead to a drop in property values in cities.
- Apple Scab affects apple trees, causing dark, scaly sores.
- Contact your county’s extension service for apple scab-resistant apple varieties.
- Fungicides prevent Apple Scab on healthy trees when applied timely.
- Canker Diseases, like Cytospora canker, affect pines, spruces, and more.
- Damaged bark or sapwood can lead to canker, blocking nutrient flow.
- Stressed trees are more susceptible to canker diseases.
- Regular pruning and proper tree maintenance reduce canker risks.
- Disinfect pruning tools with bleach solution to prevent canker spread.
- Cedar-Apple Rust requires cedar trees for its life cycle.
- Cedar-apple rust causes yellow-orange streaks on leaves and fruits.
- Fungicides can be used in spring against Cedar-Apple Rust.
- Diplodia Tip Blight targets stressed conifers like the Austrian pine.
- Regular mulching and watering can prevent Diplodia Tip Blight.
- Dothistroma Needle Blight affects pine trees, leading to needle browning.
- Copper fungicides can be used against Dothistroma Needle Blight.
- Fire Blight causes drooping and blackening of leaves.
- Humid conditions promote the growth of Fire Blight.
- Fruit trees, like apples and pears, are vulnerable to Fire Blight.
- Pruning infected branches helps control Fire Blight.
- Oak Wilt, a fungal disease, specifically targets oak trees.
- Oak wilt can spread via roots or beetles attracted to fresh cuts.
- Pruning oaks during the growing season can risk Oak Wilt spread.
- Powdery Mildew is identifiable by a white powdery coating on plants.
- Shade and damp conditions make plants prone to Powdery Mildew.
- Resistant plant varieties can help combat Powdery Mildew.
- Phytophthora Root Rot affects plants in poor drainage areas.
- Proper drainage and planting in suitable areas prevent root rot.
- Bald cypress and willow trees thrive in damp areas, reducing root rot risks.
- Regular soil testing helps prevent diseases like Phytophthora.
- Using hydrogen peroxide can eradicate soil infections effectively.
- Diseased plant parts should not be composted or mulched.
- Planting disease-resistant species helps combat root rot.
- Proper tree care and maintenance reduce the risk of diseases.
- Pruning during winter helps maintain tree health.
- Identifying trees correctly ensures they receive the right care.
- Arborists can provide detailed tree care advice.
- Early detection of leaf wilt or cankers can save a tree.
- Regular tree checks help in early disease detection.
- Consult professionals upon spotting unusual tree symptoms.
- A routine tree care regimen ensures a thriving and disease-free forest.
FAQs About Trees
What Is Apple Scab, And How Can I Manage It In My Apple Trees?
Apple Scab leads to scaly, black lesions on apples and leaves. Regular pruning, fungicides, and selecting disease-resistant apple varieties can help manage it.
What Are The Signs Of Verticillium Wilt, And Can It Be Treated?
Verticillium Wilt causes wilting, yellowing leaves and branch dieback. There is no cure, but managing the disease includes pruning affected branches and maintaining tree health.
How Can I Identify And Treat Powdery Mildew In My Trees?
Powdery Mildew results in a white, powdery growth on leaves. Pruning, improving air circulation, and using sulphur-based fungicides can help control it.
What Is Brown Rot, And How Can I Protect My Stone Fruit Trees From It?
Brown Rot affects stone fruit trees like peaches and plums. Remove infected fruit, prune affected branches, and apply fungicides during the growing season.
How Do I Prevent Tree Diseases In The First Place?
To prevent tree diseases, maintain proper tree care, provide good soil drainage, avoid overcrowding, and select disease-resistant tree varieties. Regular inspections and timely treatment are also crucial for early disease management.
