Raspberry diseasescontribute to yield losses, lower fruit quality, slower growth, and in extreme situations, also dieback of entire shrubs. Ignoring the disturbing symptoms and the lack of actions aimed atfighting raspberry diseases , leads to the spread of pathogens in the following years. Here are the most commonraspberry diseases and how to combat themin allotment and home gardens. Discover the best ways to get he althy raspberries from your own garden!
Raspberry diseases
1. Raspberry shoot dieback
Dieback of raspberry shoots caused by the fungus Didymella applanata isthe most dangerous disease affecting raspberries . Infection occurs at places where water accumulates, i.e. in the leaf axils and at the nodes.
The firstsymptoms of raspberry shoot diebackare purple-brown spots on the shoots. The spots merge with each other, covering a significant part of the shoot. In the fall, when the shoots become woody, the spots take on a silver-gray shade. Small, dark spots (fungus spores) are visible on the surface of the stains. The bark on the affected shoots peels, cracks and falls off. The infected shoots die the following year.
The characteristic stains and peeling of the bark are typical symptoms of raspberry shoot dieback
Fig. made available by Mr. Adam, our Reader. Thank you!
Dieback of raspberry shoots
Fig. made available by Mr. Adam, our Reader. Thank you!
Fighting this raspberry diseaseconsists in removing sick shoots, especially in early spring. During the period of intensive shoot growth, we perform protective spraying using chemical preparations: Mythos 300 SC (25 ml in 10 l of water / 100m²), Rovral Aquaflo 500 SC (20 ml in 6 l of water / 100m²), Switch 62.5 WG (8 -10 g in 7-10 l of water / 100m²) or the biological agent Polyversum WP (2 g in 6-7 l of water / 100m²). I recommend the latter especially for use in home and allotment gardens, where we want to obtain he althy fruit and free from chemical contamination.
2. Gray mold on raspberries
Gray mold is the second most dangerous diseaseraspberry disease . Its culprit is Botrytis cinerea, which attacks many other garden plants. The risk of gray mold increases in highly dense raspberry plantations, especially in rainy summers.
This raspberry disease developson the above-ground parts of shrubs. Raspberry flowers and buds, affected by gray mold, turn brown and dry. Large, light brown spots appear on young shoots in spring.
Paralysis of fruit inof this raspberry diseaseoccurs at various stages of development. Until puberty, the disease is latent. Only during the harvest period (especially on rainy days) the characteristic blue coating appears on the fruit and the fruit rot.
Fighting gray mold on raspberriesis about reducing the source of infection. Bushes should be systematically thinned, removing the excess of young shoots. The purpose of this is to make the plantation airy. After harvesting, fruit remains, which are the source of infection in the next year, should be removed from between the bushes.
Chemical protection of raspberriesagainst gray mold goes hand in hand with protection against shoot dieback. Spraying is performed before and during the flowering of raspberries, using the same preparations as in the case of shoot dieback.
3. Raspberry anthracnose
Anthracnose is a rather harmless buta common raspberry disease It is caused by the fungus Plectodiscella veneta. It appears on plants from early spring. Anthracnose inhibits the growth of shrubs and shoot tip dieback. The disease spreads during long rainfalls.
The symptoms of raspberry anthracnoseare gray spots surrounded by a brown border that appear on the leaves and petioles. Sick leaves turn yellow and fall off. Similar symptoms occur on flower stalks and calyx sepals.Fruits as a result of raspberry diseaseare small, deformed, hard and dry.
Raspberry diseases, photo: Juras, forum.PoradnikOgrodniczy.pl
The greatest threat to raspberry bushes is the infection of the sprouts. The infected shoots develop numerous small whitish spots, merging into large clusters. In the following year, depressions deep into the shoot are formed in the places of infection. This results in cancerous changes and distortions of shoots.
Fighting raspberry anthracnose
4. Raspberry dwarfism
Raspberry dwarfism is a very dangerous disease caused by mycoplasmas.Symptoms of this raspberry diseaseare visible only in the second year after infection. Raspberry dwarfism is transmitted mainly by raspberry pests, such as leafhoppers.
At the base of the shoot, numerous thin shoots on which no flowers appear. The shrub takes a broom-like habit. Short side branches develop on two-year-old shoots. Distorted flowers develop on them and bear fruit poorly. The condition of the bushes deteriorates from year to year, as a consequenceraspberries affected by this diseasestop bearing fruit and die.
As soon as bushes with symptoms of dwarfism are noticed, they should be removed from the plantation together with the roots. He althy seedlings from reliable sources should be used to establish raspberry plantations.When growing raspberries, it is essential to control pests such as leafhoppers and aphids, which are vectors of the disease.
MSc Eng. Agnieszka Lach
