Prevention and treatment of different blackberry diseases

Anthracnose

A fungal common foliage and cane disease of blackberries

Anthracnose (causative agent - the fungus Elsinoe Veneta) is a fungal common foliage and cane disease of blackberries. This disease is first visible in the spring as small purplish spots on new canes ads as purple-bordered spots on leafs. As spots on canes enlarge, the become oval in shape and gradually turn gray. Badly infected canes dry out, crack, and cane tips die back. Leaf spots become white with age, and affected tissue frequently drops out leaving a shot-hole effect. The causal fungus also attack fruit, resulting in small, dry, scabby berries. Certain berry cultivars are very... read more

Cane Blight

This fungal disease appears only on fruiting canes, infection occurs on primocanes near the end of the growing season

Cane blight is caused by a fungus Leptosphaeria coniothyrium. On the canes spore chambers (pycnidia) are developed in which are produced enormous numbers of brown spores. These are exuded in such quantities as to form the smutty discoloration described. These pycnidia, formed on the fruiting canes, produce spores thruout the summer. In the meantime the new canes are growing up among the fruiting canes, and when these are headed back the fungus is given a chance to infect them at the wounded ends. Infection at other points on the new canes may occur during the summer, but it usually appears... read more

Crown Gall

Caused by tumor-inciting bacteria Pseudomonas tumefaciens present either in the soil or on root cuttings

Crown gall disease is caused by tumor-inciting bacteria Pseudomonas tumefaciens present either in the soil at planting time or on propagative root cuttings.
The disease can be recognized by the presence of galls or tumors on the roots or on the crowns either below or just above the soil line. Galls may range from pea-size or smaller up to several inches in diameter. Plants may be stunted or weakened by crown gall bacteria. This makes them susceptible to invasion by other soil organisms.
The galls at first ate small, light green, and soft. Later they become very large, hard, and turn to a dark... read more

Fire blight

Fire blight is a disease that is very environmentally dependent, and warm, wet weather at flowering is most conducive to serious disease development

Fire blight is a bacterial disease, caused by the bacterial pathogen Erwinia amylovora, which exhibits symptoms on leaves, canes, flowers and fruit of raspberries and blackberries. Although this is the same organism that causes fire blight on pear and apple, it is a different strain. Thus the strain that attacks raspberries and blackberries will not infect apple or pear and vice versa.
The bacteria are likely spread from plant to plant by insects, wind, and splashing water. Rain, high humidity, and warm temperatures favor disease development. It is not known how and where the bacteria... read more

Grey Mold

Widespread and very contagious fungal disease Botrytis cinerea

Grey mold is a fungal disease, caused by fungus Botrytis cinerea. It's spores are around us (in atmosphere, soil and water) all of the time, and it lives on both living and dead plant material.
Botrytis at first appears as a white growth on the plants, but very soon changes to a grayish-white, and next to dark gray. These gray spores form and are spread by the wind or in water. In greenhouses and tunnels any activity will result in a release of spores. Even automated trickle irrigation systems, when turned on, trigger a release of spores. These spores are often found on the outside of seeds.... read more

Nematodes

Lesion and dagger nematodes on bramble canes and roots

Nematodes are elongate, tubular organisms that looks like very small snakes or worms. They live in the soil and water. They are one of the most successful and adaptable of animal groups, being rivalled only by insects as regards range of habitats or number of species.
Several nematode species are parasitic to blackberry plants. Soil populations of these parasites may increase considerably as plants age, resulting in dwarfed fruiting canes and smaller fruit. Damage generally is most severe in light, sandy soils. During hot summer months or under severe moisture stress, foliage of heavily... read more

Orange Rust

A fungal disease with no treatment

Orange Rust disease is caused by a fungus Gymnoconia Interstitialis that moves systemically throughout infected blackberry plants, rendering them useless for future production.
This blackberry disease is recognized easily by the large masses of orange colored spores produced in the spring on the leaves of affected plants. As leaf expansion is completed in late March or early April, large orange pustules form on the undersides of leaves, often causing distortion and upward leaf rolling. The pustules rupture and release spores for a period of about 60 days. Rust symptoms then disappear, but... read more

Phytophthora Root Rot

Phytophthora is a very dangerous fungal incurable disease of blackberries

Blackberries that were planted in the wet soil conditions or periods of flooding are often susceptible to Phytophthora root rot.
The disease is caused by Phytophthora fragariae Hickman. These soilborne pathogens are most often associated with heavy soils (with low amount of oxygen) and poorly drained areas. Excess water not only promotes susceptibility of roots to this disease, but also aids the fungus in moving to new infection sites. New infections occur when the pathogen releases motile spores that are carried via water to susceptible hosts. These swimming spores also enable the organism to... read more

Rosette or Double-Blossom

A fungal (maybe, bacterial) disease that prevents normal blackberry growth

Rosette, also known as double-blossom or witch's broom, is another fungal (or phytoplasma bacterial as another version) disease that prevents normal fruit development. Both wild and cultivated blackberries are susceptible. Observations made at the Overton Research and Extension Center indicate varieties differ in their susceptibility to rosette. Humble has high resistance, whereas Comanche and Cheyenne are very susceptible. Cherokee, Bryson and Womack are moderately susceptible. Brazos and Rosborough are moderately resistant. Varietal resistance may not be permanent.
Symptoms of rosette are... read more

Septoria Leaf and Cane Spot

Leaf spot and Septoria cane spot is one of the most common diseases of blackberries

One of the most common diseases of blackberries, leaf spot and septoria cane spot is not usually regarded as destructive. This disease seems to be generally prevalent wherever plants are grown, and the most of varieties are susceptible. Septoria leaf spot is caused by Mycosphaerella rubi (Septoria rubi). It affects mostly erect and trailing thornless blackberry cultivars. The disease is quite successfully cured. Symptoms are very similar to Anthracnose.
Minute purple dots appear on the leaves about the first of June or later (in southern regions may be early) according to weather conditions.... read more

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