If you work in an orchard, there’s a good chance that you know everything there is to know about your particular produce. You know the exact soil pH your trees need, the amount of pressure you expect to see your fruit withstand from the penetrometer, and the proper sugar content average from fruits across the orchard.

But like most industries, many of the people who tend to orchards have become compartmentalized. Two hundred years ago a person could be an expert in every type of fruit tree and plant, but later they’d have to specialize in citrus trees. Today you have to be a specialist in a particular fruit, and often a particular variety of fruit.

Because everyone has become so specialized, it’s natural for those in one orchard to have no idea what’s going on in a separate growing industry. If you deal in citrus, you might not know apples very well. Here are some of the problems facing apple growers starting with those that mainly cause cosmetic problems and moving on to diseases which can kill the whole tree.

Sooty Blotch

While it sounds like a villain in a Charles Dickens' novel, Sooty Blotch is actually a fungus that affects the apple itself. It leads to gray or black spots on the fruit; fortunately, the fruit isn’t technically damaged at all are are perfectly edible. Unfortunately, it makes the fruit considerably harder to sell.

The fungus most often occurs in areas where there is poor air circulation and and humidity is high during the cool season. Growers can’t control the humidity, but they can properly prune trees so that they get enough circulation in order to discourage the fungus. Not planting trees too close together is another good preventive tactic.

Flyspeck

Like sooty blotch, flyspeck doesn’t make the fruit any less edible as long as you peel it. Once again, though, it can make an entire crop unappealing to potential buyers.

Flyspeck is caused by a fungus called Zygophiala jamaicensis, which creates tiny groups of specks on the apples. Like most fungi, Zygophiala jamaicensis thrives in moist, dark conditions. Opening up a tree’s canopy with proper pruning can increase air circulation and keep the fungus from thriving.

Powdery Mildew

Powdery mildew doesn’t just affect apple trees and can be a bane of many orchards and farms. Powdery mildew is a fungus that covers leaves and can reduce the amount of blossoms (and therefore fruit) on a tree. Some varieties of apple trees are simply more susceptible to powdery mildew than others.

Treatments include fungicides, but like funguses powdery mildew can be prevented by proper pruning of the tree’s canopy, allowing more air to flow through.

Apple Scab

Apple scab certainly make apples look ugly! This fungus causes lesions to grow on the undersides of leaves, causing them to crinkle. This means that the fungus is close to the blossoms and incoming fruit. When the fruit grows, brown lesions grow and cause the easily noticeable scab to form.

Fungicides are often the most common way to treat the problem. Stopping the problem once it’s noticed on the leaves will usually prevent it from transferring to the fruit. Another great option is to clear away the leaves from the orchard, because the fungus overwinters on dead leaves.

Apple Rust

You don’t often think about evergreens and deciduous trees affecting each other, considering how different their life cycles are. But when it comes to apple rust, the cedar apple is to blame. Cedar apples are actually fungal gauls that grow on cedar trees. This fungus then blows to nearby apple trees where it starts to do damage. Leaves become infected first, turning yellow and orange long before fall. The infection can also travel to the apples themselves. If the infection is bad enough, the entire tree can become defoliated.

Prevention is the most surefire way of handling the problem. Removal of red cedar trees within a two mile radius will fix the problem, or removing the gauls when they are small and not yet producing spores. These options aren’t always an option when dealing with neighboring properties, so fungicides are also available.

Black Rot

Black rot is caused by the fungus Botryosphaeria obtusa. It begins on the leaves as small purplish spots. Over time the ring remains purple while the inside of the spot turns brown or yellow. Heavily-infected leaves can drop from the tree, but more than likely they’ll pass the fungus to the blossom and then the fruit. Green apples should be green, but with black rot you’ll notice purple or red flecks that grow as the fruit does, often causing blossom end rot.

Unfortunately, the probably only gets worse year after year. The best way to prevent black rot from happening in subsequent years is to remove fallen leaves and cankers that form and then destroying the infected material immediately.

Fire Blight

Despite its name, fire blight isn’t caused by the tree being touched by fire. Fire blight is actually bacterial and affects the entire tree. Branches will die, and blossoms and leaves may be stunted and simply die on seemingly healthy branches. Branches can also show depressions and signs of discoloration, which are actually signs that the tree is dying and rotting on the inside.

Fire blight affects apple trees as well as other members of the Rosaceae family, including pears. Unless treated, it often leads to the death of the tree, and possibly the entire orchard.

Collar Rot

Collar rot is caused by the fungus Phytophthora and attacks the root collar. It most often affects young trees in their first years of producing fruit.

There are certain problems to look out for when identifying collar rot. Like many diseases, the branches will probably be stunted, fruit will be smaller, and leaves might be discolored, especially if the leaves turn red too early in late summer. Cankers will begin to form at the root collar.

Prevention includes proper planting of the tree; since it’s a water-borne fungus, soil must be well drained at the base. Some rootstocks are more susceptible than others, so if collar rot is common in your area you might want to investigate which apple trees to plant in the first place. In established trees, exposing the roots at the collar and scraping the infected area can help. In most cases a fungicide will be necessary in order to save the tree. If caught early enough, fungicides can have an excellent success rate.

Phew, apple trees can be hard work! If you can, you’ll probably want to avoid the use of fungicides as much as possible, and that often means opening up the canopy of a tree with loppers and pruners. Shovels can also be a great option when you’re exposing roots. Frostproof Growers supply is here to help!