Blackberry Orange Rust Treatment: Managing Blackberries With Orange Rust
Orange rust (Cane) and Leaf Rust (Leaf) are two different types of fungi which affect black berries. They cause black berries to become discolored or even turn completely brown. If left untreated, they will eventually kill the plant.
The best way to prevent these diseases from destroying your fruit trees is by keeping them healthy and happy!
What causes orange rust?
The exact cause of orange rust is not known, but it usually results from poor growing conditions. Poor soil quality, improper pruning practices and insect infestations are some of the factors that may lead to the disease. Other possible reasons include exposure to sunlight, excessive watering and overwatering.
How does orange rust affect blackberries?
If left unchecked, orange rust can destroy a tree within three years. Symptoms of the disease include yellowing leaves and branches. These symptoms appear first on young shoots and then spread throughout the tree. Eventually, all parts of the tree will show signs of damage including dead wood and dying foliage. When this happens, it’s time to cut back on fruit production until the disease is controlled or removed from your area.
How to get rid of orange rust?
The best way to control the spread of orange rust is by planting disease-resistant blackberry plants. These plants have been bred to be immune to specific diseases. They are especially helpful if you live in an area where the particular disease occurs a lot. In addition, maintaining proper hygiene and proper pruning practices can help keep the disease from spreading. It is also important to prune back branches and leaves from infected trees. These should be burned or buried away from your property.
How to identify leaf rust?
Leaf rust is a fungal infection that affects blackberry leaves. The disease causes the leaves to become yellow and deformed. As a result, the berries may also turn yellow or drop off the stem. The best way to control leaf rust is by removing and burning all diseased leaves. If the disease becomes too severe, cut back on fruit production for one to two years.
How to prevent leaf rust?
The best way to prevent leaf rust is by planting disease-resistant blackberry varieties. These plants have been bred to resist specific diseases. In addition, it is important to provide adequate spacing between different crops. This allows good air flow and sunlight to reach each plant. It also prevents plants from competing with one another for vital nutrients. Finally, you can maintain good sanitation practices. This means removing and burning all diseased leaves, sticks, and other debris in your yard.
Common name: blackberry rust
Scientific name: Gymnosporangium spectabile (Aust.) C.F.Alexop.
and G.Endr., Ceratocystis gangene (Berk. et Broome) W.T.Wang and others.
Biology: There are several fungal diseases that plague the blackberry plant, all related in some way to the genus Gymnosporangium. Some of the most important are: orange rust (G. Spectabile), leaf rust (G.Endr.) and blackberry blister (G.Nigricans).All these fungi over-winter in dead twigs or leaves that remain attached to the plant, then in the spring send out little tubes, called haustoria, that invade the living plant tissue.These fungi need two different species of plants to complete their life cycle.
One of these, which is always a white pine, is called the “HOST FIGURE”, while the other, which is a various plants belong to the rose family (including blackberry), is called the “HOST RECEPTACLE”.
Symptoms:These diseases affect the leaves and stems of blackberry bushes, turning them first yellow, then brown and nasty-looking. Often they cause the tips of the canes to die back.The fruit does not get infected but it does lose its shine and drop off the stems prematurely.
Control:The best way to control these fungi is by keeping your plants healthy with plenty of water and nutrient, but most important of all, lots of air around them.
Blackberry rust can be a serious disease if allowed to infect your plants, but by following strict sanitation procedures it is easy to control. Any infected material such as leaves, twigs and old canes should be removed from the patch and burned. Any tools used out in the patch such as secateurs or pruning saws should be cleaned immediately after use with a solution of water and bleach.
Common name: Cane blight
Scientific name: Rhizoctonia bataticola
Biology: Cane blight is caused by a fungus that attacks the stems and roots of blackberry. The fungus survives from season to season in dead and decaying canes, so it is important keep the patch free of old canes. The disease spreads in wet seasons and in patches where canes are overcrowded.
Symptoms: Brown spots appear on the stems and black rotten spots develop at the base of infected canes. The fungus also affects the roots, which turn brown and die.
Clusters of small bristly black bunches develop on the underside of affected leaves.
Control: The key to control is removal and destruction of diseased canes as soon as they are found, and burning them. The patch should be kept weeded and free of dead canes.
The use of nitrogenous fertilizer should be avoided, as it tends to promote lush growth and hence greater disease susceptibility.
Common name: Red-headed cane beetle
Scientific name: Pyrrhalta viburni
Biology: Red-headed cane beetles attack the stems and roots of blackberries. They are small shiny black insects with a red head and grow up to 4mm long. They are active from May to September but the adults do not feed on the plants, so do not cause any direct damage.
They just lay their eggs in the soil. Under favourable conditions these eggs hatch into larvae that tunnel through the soil and attack the roots of blackberry plants.
Symptoms: The presence of red-headed cane beetles is signaled by little piles of sawdust-like material at the base of blackberry canes.
Both the adults and the larvae tunnel through the roots, which turn hollow.
Control: Periodic tilling will help to control the pest, since it will bury the insects’ eggs. Also, if only one or two plants are affected, they should be removed and burned and the area around the plant tilled lightly.
Control of this insect has not been found necessary.
Common name: Thrips
Scientific name: various species
Biology: These tiny insects are hard to see without a magnifying glass. There are many different species of thrips, some of which attack blackberries. They are less than 1mm long and have a frayed appearance.
They have a nasty habit of sucking fluids from plants, causing leaves to curl and de-green. Some species feed on the pollen and nectar as well.
Thrips are winged insects, and can move rapidly from one plant to another. This helps to spread them around, but also makes them harder to control since they can fly out of the patch before you know they are there.
One very serious species of thrips is the tomato thrips. It is barely visible to the naked eye, and attacks a wide variety of plants, including tomatoes. Blackberry leaves curl and discolour when attacked by thrips.
Control: Yellow sticky traps work well to catch adult thrips. They are only useful before the thrips appear, since after they appear it is too late.
Insecticidal soaps or horticultural oils can be used at the recommended rate. These must be applied thoroughly since thrips tend to hide in harder to reach places.
In severe cases a miticide may be used, but always follow the manufacturers instructions carefully.
Common name: Root-knot Nematode
Scientific name: Meloidogyne spp
Biology: These microscopic worms are found in the soil. The female enters the root of a plant and injects saliva which irritates the root and causes it to grow in a knotty manner. This weakens the roots and makes the plant more susceptible to drought and disease.
The female then lives inside this knot.
Serious infestations of root-knot nematodes can result in the death of the plant.
These nematodes are difficult to see without a microscope, but the symptoms they cause can be seen easily.
Control: Isolate infected plants thoroughly before removing them and burning them. The area should then be tilled and a recommended nematode poison applied to kill the remaining worms.
This is a fairly difficult procedure for the amateur, and most people will prefer to grow resistant varieties such as Blackjack, Cheyenne, Apache or Navaho.
Blackberries are prone to a variety of fungal diseases:
Common name: Blackberry Scab
Scientific name: “Mycosphaerella” species
Biology: Scab is a fungal disease that affects all parts of the blackberry plant, but is most noticeable on the leaves. It appears as dark greenish spots on the upper and lower sides of leaves. As the spots mature they turn gray or black and become rough and hard.
Scab spreads over the leaf, eventually causing it to crack and tear. Severe infestations can cause the death of the leaf.
Control: The use of bio-fungicides early in the growing season helps a great deal. It is important to choose a product that contains the ingredient Mancozeb or one of its chemic cousins. There are many fungicidal sprays that contain lime sulfur or other ingredients which will not do as good a job.
Blackberry bushes suffer from few insect infestations:
Common name: Yellow Pine Spider Mite
Biology: These tiny reddish-brown spiders are up to one-third of a millimeter long, making them difficult to see without a hand lens. They often gather in colonies and spin small webs near the base of blackberry leaves.
Mite damage appears as stippling or boiling on the top side of the leaf. Infestations cause leaves to curl and yellow, which normally leads to the death of the plant.
Mite infestations are among the most common problems faced by blackberry farmers and can only be rectified through the use of insecticides.
Control: The use of neem or horticultural oil helps to prevent mite infestations by killing the eggs. If an infestation appears, it is best to spray with one of the following:
Common name: Broad mite
Biology: These tiny yellow or reddish-brown mites generally live on the undersides of leaves. They feed on the juices of the plant and can cause a great deal of damage. Severe infestations can lead to the death of the plant.
The most obvious sign of a broad mite infestation is stippling or spotting on the underside of leaves. Leaves with heavy damage turn yellow and drop off.
Control: Begin by washing the infected plant with a strong stream of water to remove adult mites that will cause new infestations elsewhere. It is important to identify and eliminate all weeds in the area as they are often a primary breeding ground for broad mites.
The spread of these mites is largely by humans. It is important to eliminate all weeds and other host plants from the area surrounding blackberry bushes.
Spray with the following insecticides:
Common name: Root knot
Biology: These microscopic round worms live in the soil and are ingested by the plant. There they form a swelling or “knot” on the roots that decrease root function and cause leaves to wilt.
Control: Areawide control of nematodes can be obtained by applying milky spore, a naturally occurring bacteria that kills all soil nematodes.
In the past, farmers have treated their soil with nematode-free loam or imported topsoil. Weaker chemicals such as chlorophacinone (trade name Diphacin) also help to control root knot.
Biological control is also possible through the use of nematode parasites.
For serious root knot problems, replant the area with strawberries, tomatoes, potatoes, or other plants that are susceptible to root knot.
Common name: Root rot
Biology: Many types of fungi live in the soil and attack the roots of plants. These fungi can live in the soil for years without causing damage but will attack when the plant is weakened or under stress.
Control: Avoid excess moisture which encourages fungal growth. Carefully examine new plants for signs of root rot before purchasing. Purchase plants from a reliable grower rather than a big-box store.
Bare root plants are most likely to be infected with root rot fungi. Plant as soon as possible after purchase, as the longer a plant is out of the ground, the more chance there is that it will become infected.
Control: Plant in well-drained soil, make sure the soil is not excessively wet. Water deeply, avoiding the crown of the plant where the roots are located.
Many pesticides are ineffective against fungi and those that are effective (such as mancozebe and mandipropamid) have not been approved for use on blackberries.
Biological control through the use of beneficial fungi such as trichoderma is currently under development.
To prevent shot-hole disease:
Common name: Shot-hole
Biology: The fungi that causes shot-hole is present in all areas where blackberries are grown. The disease enters the plant through the leaves, and then attacks the water-conducting system (the xylem). This causes tiny yellow spots about 1 to 5mm in diameter to appear on the top of younger leaves.
As the disease progresses, these spots enlarge into ‘shot-holes’. The leaves then turn yellow and fall off, while new leaves appear deformed.
Control: Isolate your patch from any others to prevent the spread of disease.
Inspect new plants before purchase and destroy those with signs of disease as they will almost certainly die.
Practice crop rotation to prevent infestation of the soil.
When pruning, remove all shoots three years or older as this is when the disease becomes active. The fungus overwinters in the shoots.
During the season, water plants from below and keep the soil on the dry side. This prevents infection.
In some areas, a virus causes blackberries to become covered in a fine white powdery substance. The leaves first turn yellow and then fall off. To prevent this, isolate new plants from infected plants and destroy them.
Although uncommon, rabbits are a constant threat to plants, especially young ones. They like to eat many common blackberry cultivars such as ‘Brazos’ and ‘Navaho’.
For a short period of time after planting, nitrogen will build up in the soil. This may lead to an overgrowth of weeds, grasses, along with other plants such as lambsquarter, pigweed, morning glory, goosefoot, and purslane. Prevention and removal is important to ensure the new plant has all the nutrients it needs to grow.
Young blackberry plants need to be protected from grazing animals such as deer and cattle. The animals will severely wound or kill the plant by trampling it while eating the leaves, stems, and fruits. Use of fencing is essential to ensure the blackberry patch survives the first few years.
The fruits have sharp points around the seeds that will tear holes in shirts, hands, and lips when harvesting. Care should be taken to avoid getting pricked.
The fruits stain very easily, so you should always wear clothing and gloves when harvesting and handling the fruit. The stains will usually come out of clothing, but not always. They also stain anything the hands touch, such as tools and other items.
Blackberries should be harvested as soon as they ripen since they do not keep well. If you wait until they are completely ripe, most will fall to the ground and rot before you can get to them.
Blackberry canes will creep along the ground and root where their nodes contact the soil. If not pruned, Blackberry patches can become huge. If this is allowed to happen, the patch will eventually stop producing flowers and fruits and will be taken over by weed plants.
New rows will have to be started to keep the patch productive.
Trees and other plants can be covered with a dense layer of vines if not kept trimmed.
Dogs, raccoons, and other small animals will sometimes dig up the soil when searching for food such as grubs or worms. This will expose the canes. A layer of mulch will prevent this.
When gathering seed, be sure to collect from several different plants. This will ensure some have better germination rates than others.
Blackberries will crossbreed very easily with other varieties. If close neighbors are growing other varieties, you will get some of the seeds mixed in with yours. It is best to isolate the rows by 500 feet (150m) if possible.
This isn’t always practical, so expect some of your blackberries to be mixed.
Blackberries can take nutrients from deep in the soil and bring them up into the canes. This is good since you don’t need to add much, but if left unchecked, blackberries can draw so much that other plants will have a hard time growing around it. This can be avoided by adding an organic fertilizer high in N and other nutrients or growing other types of plants between the rows.
Blackberries can be harvested year round, but most are not available in the Winter. The months of May through July have the most selection with the majority being harvested in June.
Wild blackberries are one of the highest sources of antioxidant (behind only blueberries and strawberries) with a higher ORAC value than cultivated berries.
The nutrients listed below are from blackberries grown in Tennessee and may vary in different climates and if fertilized.
One ounce (28 grams) of fresh blackberries contains:
0.8 mg vitamin C (1% Recommended Daily Allowance)
3.2 mg vitamin K (5% Recommended Daily Allowance)
6.5 mcg vitamin B1 (8% Recommended Daily Allowance)
2.3 mg iron (15% Recommended Daily Allowance)
3.4 mg magnesium (5% Recommended Daily Allowance)
0.1 mg vitamin B3 (1% Recommended Daily Allowance)
2.1 mg copper (8% Recommended Daily Allowance)
0.1 mcg vitamin B2 (1% Recommended Daily Allowance)
5.5 mg phosphorus (6% Recommended Daily Allowance)
0.3 mg vitamin B6 (2% Recommended Daily Allowance)
26.0 mg potassium (2% Recommended Daily Allowance)
1.3 mg zinc (2% Recommended Daily Allowance)
0.2 mcg vitamin E (1% Recommended Daily Allowance)
0.2 mg vitamin A (1% Recommended Daily Allowance)
Almost all these nutrients will become more concentrated when blackberries are dried.
Blackberries are very low in protein and fat and contain no cholesterol.
Blackberries are an especially good source of certain flavonoid antioxidants, which is what gives them their dark blue color and is also found in many other brightly-colored plants.
These flowers are named after a plant called ragged sailors (or dusty doors) that has yellow flowers and grows in sea ports. Sailors would pick the yellow flowers and bring them home to their girlfriends. These flowers are also known as wild cosmos.
The ragged sailors, yellow flowers that they are, have no scent. Black-eyed Susans on the other hand are heavily scented. They smell like a combination of magnolias and gardenias.
The only problem is that the scent is very faint and you really have to be downwind in order to smell it.
The Black-eyed Susan is the state flower of Kansas and Texas.
Black Wattle (Acacia Merica).
This tree blooms in the late Winter to early Spring, the flowers are yellow and pea sized. It’s common along river banks and in open woodlands. It has large compound leaves that give it a distinctive look, the tree is easy to identify even when no flowers are present.
It is also called the Golden Wattle.
The flowers produce a lot of nectar and are a good source of food for many insects and birds.
These berries are related to the raspberry, they can be black, purple or red. They have a bad reputation as a invasive species and a common allergen. In some places they have been listed as a noxious weed.
Black-Eyed Susans (Rudbeckia Heterotrphylla).
This is an ornamental flower that has been naturalized in the United States from Canada to Mexico. It gets it’s name from the fact that the center of the flower is usually a solid black, like the eye of the popular children’s toy.
It’s a member of the Asteraceae (Aster) family and is closely related to the Coneflower.
Black-eyed Susans are usually white, yellow or orange, with very few being blue. The black spot is always in the same place on each flower and is surrounded by a ring of yellow. Both the petals and the center cone have hairs (known as pubescence).
They grow in prairies, open woodlands and along roadsides.
The Black-eyed Susan is the state flower of both Texas and Oklahoma.
Black-Eyed Susans are edible, the entire flower is eaten including the cone and petals. They are usually eaten raw, but sometimes they’re boiled for 5-10 minutes in water to reduce the bitter taste.
The leaves can be used as a tea substitute. The tea has a minty flavor.
They also make good bait for fishing.
Black-eyed Susans are rich in vitamin C and have some vitamin A and calcium.
Blazing Star (Liatris).
This flower is also known as the Gayfeather. It’s part of the Lilaceae family and related to the Wild Garlic, neither of which have much of an odor, they’re both slightly garlicky tasting though. The Blazing Star is sometimes called the Common Gayfeather.
The flowers bloom from July through September. They have a 2-3 inch diameter, the petals are purple and rayed. The flower heads sit atop 15-30cm stems.
The leaves are lanceolate shaped and up to 15cm long.
Blazing Stars grow in sunny meadows and open areas with disturbed soil. They’re common throughout most of North America.
They’re edible and have a mild, onion or garlic flavor. The leaves can be eaten raw or cooked. They can also be dried and stored for later use.
Blazing Star is also called the Gnome’s Onion, which leads to the interesting suggestion that they can keep hobbits alive under the right conditions.
Black Locust (Robinia Pseudoacacia).
This tree produces white flowers in late Spring that give off a sweet scent. They’re poisonous though and can cause blistering of the lips and mouth if eaten. The tree is native to both North America and China.
The tree has long been popular in the construction trade for its strong, rot-resistant and honey-colored wood. It was once commonly used to build ships, wheelbarrows, tool handles and fence posts. The wood is still sometimes used in cabinetry.
Its durable and attractive grain makes it valuable for fine furniture as well.
The black locust wood contains a natural chemical that repels most insects. It is sometimes used as a natural pesticide, sometimes even more effective than commercial varieties.
The wood burns well, but it creates a lot of soot. It also creates long lasting coals. It’s very important to keep the firebox clean if you plan to use it for cooking or boiling water.
Black locust flowers are edible and have a slightly sweet taste. They’re good in salads or can be boiled and eaten like corn on the cob. They should be eaten shortly after picking though, as they don’t keep well.
Black locust trees grow very quickly. They mature within a decade and start producing flowers after three. Sometimes they get so big that their roots tear up sidewalks, roads and even buildings when they reach a certain age.
They have to be carefully managed when grown in an urban setting.
Blackberries (Rubus fruticosus).
Also called brambles, blackberry bushes are a fast-spreading plant found in temperate regions of the world. They have sharp prickles and produce edible black berries. They’re related to raspberries, loganberries, dewberries and olallie berries.
Blackberries can be eaten raw or cooked into a variety of dishes. They are high in vitamin C and antioxidants.
Blackberry leaves have a high vitamin and mineral content and can be eaten in a survival situation if no other food is available. They should only be eaten in extreme emergencies though as they cause diarrhea.
Blackberry roots, stems and leaves contain chemicals that can be used to make medicine. A tea made from the roots is used to treat diarrhea. A poultice of the prickly stems soothes insect bites and inflammation.
Blackberry leaves and stems contain a natural dye that can be used to color clothing and leather items a deep purple.
Bladder Nettle (Utricularia gibba).
Native to Eurasia, this small flowering plant has spread to North America as a result of being used in ornamental gardens. It’s also sometimes found growing wild. The Bladder Nettle grows both on land and in water, where it uses tiny hairs on its leaf stems and flowers to suck up nutrients.
The plant’s tiny hairs also act like tiny hypodermic needles, injecting a poison into whoever brushes against them. The sting causes a burning rash and severe blistering that can last for several weeks.
The root of the Bladder Nettle can be boiled to make a tea with healing properties. It was mostly used in the past to treat urinary tract inflammations as well as other internal swelling problems.
Blazing Star (Liatris spicata).
Also called Spicy Gay Feather, this plant is native to North America. It grows in open fields and grasslands. The flowers are dense purple tufts that bloom in the summer.
The roots of the Blazing Star can be boiled and the decoction used as a medicine to treat topical infections and fungal growths. It’s most commonly used to treat ringworm. While effective, it does have a high rate of allergic reactions.
Taken internally, the roots can cause vomiting and diarrhea. If enough is taken it can lead to blurred vision and even temporary blindness.
Blighia (Blighia sapida).
Also known as the Acca Fruit, this fruit grows on a small evergreen tree native mainly to West Africa, the Caribbean Islands and South America. The fruit is round, about a foot in diameter and dark green when ripe. Its flesh is white and creamy, and tastes a bit like a mixture between an apple and a pear.
It has a single large seed which is the Blighia, also edible once the fruit is cooked.
These fruits have high nutritional value, and are most often eaten raw. They can be made into juice, vinaigrette, wine, or alcohol when fermented.
The Blighia tree grows slowly, only producing fruit after several years.
Sources & references used in this article:
New leaf rust helps to control blackberry by J Dodd, S Lloyd – Journal of the Department of …, 1992 – researchlibrary.agric.wa.gov.au
Temporal dispersal of brown and orange rust spores of sugarcane in Florida by B Chaulagain, M Kanaan, RN Raid, JC Comstock… – 2019 – agritrop.cirad.fr
Blackberry Diseases and Their Control. by GL Philley, LR Smith – Texas FARMER Collection, 1982 – oaktrust.library.tamu.edu
Sugarcane cultivars susceptible to orange rust can host sub-populations of Puccinia kuehnii capable of infecting resistant cultivars by G Ecker, L Porto, RS Arias, LM Cano, P Rott… – 2019 – agritrop.cirad.fr
Blackberry and Raspberry Culture for the Home Garden by K Woodburn, D Hillock, B Carroll – 2015 – shareok.org
Orange Cane Blotch Disease of Blackberry and Management with Potassium Phosphite by JE Oliver, WH Hemphill, PM Brannen – smallfruits.org
Blackberry Cultivar Trial at Princeton, Kentucky by D Wolfe, V Fenton, J Johnston, G Travis – 2009 Fruit and Vegetable Research … – ca.uky.edu