After all the time, energy, and effort you put into your apple harvest, you don’t want to let the disease steal your fruits, right? Apple tree diseases spread quickly from tree to tree. To help you fight back, we’ve simplified the most common diseases and the best ways to treat them.
By doing proper care and treatment, you can control many harmful diseases. Spotting symptoms early is key to protecting your healthy apple trees from infection. However, remember that some apple varieties respond well to treatment, while others have no cure.
Apple Tree Varieties
There are thousands of apple varieties available worldwide. Each variety has its unique size, color, shape, flavor, texture, ripening time, storage life, and disease resistance. Apples fall into three categories: cider, cooking, and dessert. These categories differ in color, size, aroma, crispness, and tang.
Popular apple varieties include Red Delicious, Golden Delicious, Gala, Fuji, Granny Smith, Honeycrisp, Braeburn, McIntosh, Jonagold, and Pink Lady. Whether you’re baking, juicing, or enjoying them fresh, there’s an apple for every taste.
Apple Tree Diseases And Treatment
Apple tree diseases aren’t the only threat to your harvest. Pests like codling moths and apple sawflies can damage fruit, while lack of water limits nutrient absorption. Extreme drought or heavy rainfall may cause fruit to split, and late frost can leave lasting damage.
Apple Canker
Apple canker is a fungal disease that attacks the tree’s woody parts and occasionally the fruit. It thrives in wet climates and also affects pear trees.
How to identify apple canker
Apple canker first appears as flaking, cracked, or sunken patches on the bark, often surrounded by raised or swollen edges. The canker may girdle a shoot or branch as the disease progresses, causing it to die beyond the affected point. White pustules can form around the canker in summer, signaling fungal activity. The infection sometimes spreads to the fruit, leading to rot and drop early. It is most likely to develop on young trees, mainly when you apply too much fertilizer.
Treatment
To control apple canker, prune out affected shoots during winter. Avoid over-fertilizing, as excessive nutrients promote soft growth and make trees more vulnerable. Apple canker likes waterlogged soil, acidic conditions, and areas with poor air circulation. Improving drainage and spacing of trees can reduce the risk of infection. For long-term prevention, consider varieties that are naturally resistant to these diseases.
Apple Scab
Apple scab damages the leaves and fruit of apple trees, often causing premature leaf drop. This disease thrives in high-rainfall areas and wet summers and can also affect other trees like Cotoneaster and Sorbus.
How to identify apple scab
Infected trees develop black or brown spots on leaves and fruit in spring. Affected leaves may fall early, while fruit lesions can merge and split, making the fruit vulnerable to further infections.
Treatment
To manage apple scab, remove fallen leaves in autumn by raking or mowing. The spores overwinter and reinfect new growth in spring. To break the disease cycle, dispose of infected leaves in garden waste collections, not compost. Many apple varieties resist apple scab, making them a smart choice for disease-prone areas.
Brown Rot
Brown rot is a fruit disease that usually enters apples through tiny holes made by birds or insects.
How to identify brown rot
Infected fruit quickly develops brown patches, which spread until the entire apple is affected. The fruit may fall to the ground or remain on the tree, covering it in creamy white pustules. Brown rot spreads quickly, especially when infected apples touch healthy ones on the tree or in storage.
Treatment
Inspect trees and the ground regularly and remove any infected fruit immediately. To eliminate the source of infection, dispose of infected apples in your garden waste collection, not in compost or left in the garden.
Powdery Mildew
It is a fungal disease that looks like a white coating on the upper surface of the leaves and can also affect the blossom. If left untreated, it can lead to further infections.
How to identify powdery mildew
To identify powdery mildew, look for a white powdery coating on the upper leaf surface. As the disease spreads, the affected leaves may become reduced in size, distorted, and eventually fall early.
Treatment
Remove diseased material to break the cycle of infection. Prune out affected shoots during summer and gather fallen leaves in autumn. Thinning dense growth during winter pruning ensures good airflow and helps prevent mildew buildup. Powdery mildew thrives in dry soil, so occasionally water deeply during dry spells. While growth invigorators and chemical fungicides are available, sprays are difficult to apply on a large tree scale.
Apple Tree Care To Prevent Diseases
Apple trees require special attention as they are susceptible to various insects and diseases. By doing proper apple tree care, you can enjoy the beauty and bountiful fruit of these trees in your garden for years to come.
The best way to prevent these diseases is to grow Apple tree varieties that are naturally disease-resistant. Varieties like Crimson Crisp, Enterprise, or Gold Rush are good choices to start with.
Prune your trees every winter to remove dead, diseased, or damaged growth, as these wounds provide entry points for disease. You should thin out the canopy to promote good air circulation and prevent branches from crossing or rubbing each other, which can cause further damage and create openings for infections.
Mature apple trees thrive with organic-based fertilizers that provide both macronutrients and micronutrients. These essential nutrients support their long-term health and help the trees maintain strong growth, produce quality fruit, and resist diseases.
