Fruit and Nut Tree Diseases in Arkansas

Arkansas produces a wide variety of peaches, apples, plums, and pecans throughout the majority of the state. An active evaluation program is in place at Fayetteville, Arkansas on the University of Arkansas campus. The fruit substation located at Clarksville, Arkansas is one of the largest fruit research areas in the United States. Testing of developments at the Southwest Research and Extension Center in Hope are carried out by the University of Arkansas. 

The most significant tree fruit diseases are caused by various fungal organisms which can affect both fruit quality and quantity.

Bitter rot of apple

Pecan scab

Peach Scab

Peach leaf blister/curl

Important Tree Fruit and Nut Diseases

Leaf Blister/Curl

This fungus disease is a common foliar disease of peach. Leaf deformities, defoliation, and reductions in fruit load are the primary effects of this disease. This disease is often mistaken for insect damage.

Scab

Scab is primarily a fungus disease of peaches, plums, and pecans. It damages the fruit or nut directly. Fungicide resistance has been documented for scab on pecans.

Bitter Rot

This fungus disease can be important on apples. It causes fruit lesions and associate fruit rot. It is usually characterized by circular and sunken lesions with concentric lines that represent sporulation of the fungus.

Fire Blight

A specific bacterium is responsible for fire blight. This disease is common on apples and pears. It results in a blighting of branches. Bacteria usually infect the open blossoms in the springtime during cool and wet conditions. This disease also affects the ornamental pear.

Cedar-Apple Rust

The fungus which causes this disease spends part of its life on the cedar and part on the apple. On apple, it produces large orange leaf spots that are raised. It can also causes a fruit rot. The fungus produces an ornate and showy telial growth stage on cedar during the spring.

Brown Rot

Brown rot attacks plums, peaches and nectarines in Arkansas. Fruits rot on the tree and are often covered by a gray "fuzz" which is the fungus that sporulates on the fruit. This disease can be severe under moist or humid weather conditions

Black Knot

This fungus disease is often confused with insect activity. Branches of the plum develop dark swellings which can kill and break as a result of infection.