Disorders Associated with Roots

Causes of Root Disorders

Fungi, insects, vertebrates, mechanical damages, as well as disruption of the gas exchange process between the roots and the atmosphere can damage roots of woody ornamentals.

Root Diseases

Root diseases can be caused by fungi that attack the fine feeder roots only and cause death and decline of the tree or by fungi that can kill the larger roots and decay them. Root diseases are doubly important in forest situations since many of the fungi can attack and kill living trees but then remain living on the dead roots and stump waiting to attack future trees. Follow the links below for additonal information about root diseases.

Root Feeding Insects

The larva of the black vine weevil and the larva of several species of Scarab beetles live underground and feed on the roots of many woody ornamental plants. Follow the link below for additional information about root feeding insects.

Root Feeding Vertebrates

Vertebrates such voles, deer mice, and pocket gophers can tunnel into the ground around woody ornamentals and feed on the roots, disrupting the movement of water from the soil to the above ground plant parts. Follow the link below for additional information about vertebrates that feed on roots.

Oxygen Starvation of Roots

Healthy plant roots require oxygen. Conditions or events that disrupt the exchange of oxygen in the root zone will have a negative impact on plant health. Follow the link below for additional information about oxygen starvation of roots.

Diagnosis Hints

Diagnosis of root diseases is difficult and can seldom be accomplished without excavating and looking for symptoms and signs on roots. Above ground symptoms include yellowing of foliage, reduced tree growth, reduced leaf size, thinning of crown and death. The same symptoms are found with over watering, drought, bark beetles, vascular wilts, and phytoplasma diseases to name a few. Examining the root crown and larger roots for stain, decay, mycelial fans, rhizomorphs, resin, and fruiting bodies characteristic of each disease is necessary for diagnosis. Look for these symptoms and signs on recently killed or better dying trees since secondary insects and fungi destroy the signs and symptoms after a year of so. It is not always necessary to figure out exactly what fungus is involved but to determine if it is an abiotic or fungal caused problem so the appropriate management options or chosen.

Annosus Root Disease Armillaria Root Disease Black Stain Root Disease Phytophthora Root and Crown Rots Root Collar Rot Root Feeding Insects Root Feeding Vertebrates Abiotic Disorders-Oxygen Starvation of Roots Abiotic Disorders - Impact of Deicing Materials on Woody Ornamentals <<< Needs a fact sheet page!