Fungal Infections in Pine Trees


According to research conducted at Oregon State University, pines make up the majority of the world’s population of coniferous trees. There are over 100 different species of pine trees, of which 30 are native to the continent of North America. The plant hardiness zones that are assigned by the United States Department of Agriculture to members of the genus Pinus range from 3 to 11, depending on the specific species. Pines, according to the Clemson State University Extension, are sensitive to a wide variety of illnesses and other difficulties; however, the majority of these problems may be avoided by planting the pines according to their unique cultural needs.

Watch for Rust Infections

Pines often suffer from infestations of the rust fungus. For instance, the Cronartium ribicola fungus is responsible for the blister rust that affects white pines (Pinus strobus). Cankers are regions of a tree’s bark that get swelled and inflamed due to a fungal infection. These trees are hardy in USDA zones 3 through 8. As the cankers become larger, they wrap or girdle the branches or the whole tree, which ultimately results in the tree’s death or severe weakening. This infection takes place when plants belonging to the genus Ribes, such as currants and gooseberries, are grown in close proximity to white pines. Take down these neighbouring plants, and then use pruners that have been sterilised to cut away any damaged parts of the pine.

The pine-oak gall rust is caused by a fungus called Cronartium quercuum. Pine trees are prone to developing growths that are known as galls. According to research conducted by PennState Extension, these galls produce yellowish spores that infect red oaks. Remove galls using pruners that have been sterilised. Needle rust is a largely harmless infection that creates whitish structures on the needles. Pine-pine gall rust is a disorder that is characterised by rounded galls on the branches. Other types of rust include fusiform, which creates galls that can later become cankers; fusiform, which creates galls that can later become cankers; and needle rust. Remove galls from plants using pruners that have been sterilised.

Check for Needlecast Disorders

The vast majority of pine species are vulnerable to needlecast diseases. The Ploioderma lethale fungus infects and kills vegetation that has previously grown in prior years. According to the Texas A&M AgriLife Extension Service, the needles on the lower crown of the tree turn brown and then fall off. This fungus does not have a substantial influence on older trees, but it may have an adverse effect on younger trees. Allocating sufficient space between the trees would facilitate healthy air circulation and make it easier to collect needle litter.

Cyclaneusma needlecast is caused by the fungus known as Cyclaneusma minus. The needles become a yellowish colour, and the surface develops some brownish stripes. The needlecast disease caused by Lophodermium typically strikes a tree around a year after it has been infected. The needles in the lowest part of the tree start to turn a different hue and eventually fall to the ground. The fungus Mycosphaerella dearnessii is responsible for the disease known as brown spot needle blight, which manifests on the leaves as bands or spots. In order to assist in the management of these diseases, increasing the light and air penetration into young pines is recommended.

Identifying Root and Wood Rot

Infections with rot almost often result in the death of trees. The fungus known as Heterobasidion annosum is responsible for the annosus wood and butt rot. Near the trunks of diseased trees, fungal bodies begin to grow, and the surrounding foliage dwindles and becomes sparse. As the roots rot and become weaker, the trees become more susceptible to being uprooted by storms. Cotton root rot may affect Afghan pines, also known as Pinus eldarica, which are prone to growing in alkaline soil and are hardy in USDA zones 10 through 13.

According to Texas A&M AgriLife Extension, the fungus known as Phymatotrichum omnivorum is the one to blame for the illness known as cotton root rot. The tree quickly withers and turns its leaves a yellowish-brown colour. White pines are susceptible to root rot brought on by the fungus Verticicladiella procera. The needles become a yellowish colour and eventually die, yet they do not fall off the tree. Near the soil line, cankers that leak fluid develop. Take down any sick trees and avoid planting pines in that area in the future.

Watch for Other Infections

The disease Sphaeropsis tip blight is caused by Sphaeropsis sapinae. The new development at the bottom part of the tree is susceptible to cankers, which are lesions that harm new growth and often result in the death of the lower branches. The blight that affects seedlings may be caused by a number of different fungus, including Pythium and Sclerotium. These fungi are responsible for the death of early seedlings.

Pitch canker is caused by a fungus that belongs to the genus Fusarium moniliforme and species subglutinans. Cankers that are sticky and ooze resin form on the tree’s branches and trunk. The Phytophthora cinnamomi fungus is responsible for the littleleaf disease that affects shortleaf pines like Pinus echinata, which is said to be hardy in USDA zones 6 through 9 according to the Missouri Botanical Garden. There is a possibility that the needles could get discoloured or small, and the crown will become thinner. After an infestation, it takes infected trees anywhere from one to six years to die. Control may be helped along by having enough cleanliness, ventilation, and drainage for the soil.