Blackberry diseases – which ones are the most common and how can you combat them?

The blackberry is a perennial shrub from the rose family (Rosaceae) that is grown for its black berries of the same name. The blackberry can also be called the beetleberry, and the bushes grow on all continents except Australia and Antarctica. The lifespan of blackberry bushes varies, but they typically live less than 10 years and reach up to 10 feet tall unless affected by disease. Some of the most common blackberry diseases are listed below.

Anthraknose (Elsinoe veneta)

Symptoms:

  • Small purple or red circular lesions on the canes that enlarge to form a gray, cracked depression in the center.
  • The edges of the lesions become raised and purple, and the lesions coalesce into large, discolored areas.
  • the canes can eventually overgrow and die.

Cause:Mushroom

Remarks: The fungus overwinters in the diseased canes; the occurrence of the disease is favored by prolonged periods of wet weather and excessive watering.

Treatment: To limit the spread of the disease in your home garden, you should take the following measures, among others. Avoid excessive nitrogen fertilizer applications, keep the areas around plants free of weeds, avoid overhead watering, and only water during the day to allow the plants enough time to dry out in the afternoon. Commercial growers may require the use of fungicides on large plantings.

Blackberry rosette, double flower (Cercosporella rubi)

Symptoms:

  • Flowers with distorted petals and enlarged sepals, giving the appearance of a double flower.
  • Unopened flowers are enlarged and redder than normal.
  • Shoots may have abnormal growths.
  • No fruits are formed on infected branches.

Caused: Mushroom

Remarks: Wild blackberries can serve as a reservoir for the disease. Flowers from uninfected canes may become infected by those on infected canes and show the following year.

Treatment: The most effective way to control the disease is to use resistant blackberry varieties. If the plants are already infected but the disease is not yet severe, you should remove and destroy any abnormal inflorescences. You should remove and destroy old canes immediately after harvesting. Applying fungicides can limit the damage. You can also combat the disease by only harvesting the fruits in the intervening years and completely destroying the above-ground part of the plants. You can divide the plantation into two parts so that the fruits of one half are harvested and the other half is pruned every year.

Blackberry diseases – Botrytis fruit rot (Botrytis cinerea)

Symptoms:

  • The canes appear pale and develop flattened masses of black fungal fruiting bodies within which gray mycelium and spores develop.
  • The fungus can infect and spoil the flowers.
  • Infected fruit seeds can develop a watery rot, which is replaced by gray-brown fungal structures.
  • If the fruits remain on the vine, they mummify

Caused: Mushroom

Remarks: The occurrence of Botrytis fruit rot is favored by cool and moist conditions. Physical damage to the fruit increases the likelihood of infection.

Treatment of blackberry diseases: Promote air circulation around the vines by using trellises or orienting the vines. Avoid oneOver-fertilization of plants. To combat the disease, you can use protective fungicides, which should be applied at intervals of 7 to 14 days from the beginning of flowering to harvest.

Blackberry Diseases – Orange Rust (Gymnoconia peckiana)

Symptoms:

  • The new growth is weak and spindly and has no spines.
  • The leaves are stunted and distorted and pale in color.
  • Waxy pustules form on the undersides of the leaves and turn orange and powdery.
  • Affected leaves eventually fall off the plant.

Caused: Mushroom

Remarks: Wild blackberries and pigberries can serve as reservoirs for the disease. The fungus overwinters in the host plant.

Treatment: Infected plants should be completely removed. Cut and burn fruit-bearing canes after harvest. Improve air circulation around the foliage by pruning and trellising the vines. The spread of rust can be minimized by using foliar fungicides when the orange spores appear. If you treat the disease well, it usually doesn't progress further.

However Mehltau (Podosphaera macularis)

Symptoms:

  • Light green, chlorotic spots on the foliage that later develop into powdery, gray spots.
  • The leaves may be twisted or deformed.
  • If the infection is severe, the shoots may become spindly and have small, upwardly curved leaves.

Caused: Mushroom

Remarks: The fungus overwinters in the buds or on the surface of the canes. Warm and dry climatic conditions favor the occurrence of the disease

Treatment: If powdery mildew is known to be a problem in a particular area, you should not grow susceptible varieties.

Culm and leaf rust (Kuehneola uredinis)

Symptoms: Small, lemon-yellow pustules appear on the stick and leaves of the infected plant. As the disease progresses, the affected cane cracks and dries out, while the leaves become mottled and dry.

Caused: Mushroom

Remarks: It is a non-systemic disease.

Treatment: Cut out infected sticks and leaves and burn them.

Blackberry problems not caused by disease

Blackberry sunscald (also known as white drupe disease) occurs during periods of dry, sunny, windy and hot weather. Excess UV radiation scalds the fruit. Individual drupes become white or light brown and hard. If only a small percentage of the stone fruit is affected, the fruit is still edible and you can also use it in recipes.

Cutting berry bushes – how do you do it correctly? Thefind out here!