Wilting strawberry bushes many faces, but there are common symptoms: the defeat of parasitic microorganisms of the root system, which leads to a violation of plant nutrition. In the list of such diseases, one of the lines is occupied by vertical withering.
There is great harm
Large. Some varieties wither about a sixth of the plants planted each season. If the berries are on the infected areas, the damage from the disease will be even more-a real plague on strawberries attacks. But the main trouble is not this.
Not all sick plants die, some remain alive, continue to grow in the beds. They become hidden carriers and breeding grounds of infection: while their yield is negligible, but they actively transmit the causative agent of the disease to healthy plants. That’s trouble.
The causative agent of vertical wilting
Mushroom Verticillium albo-atrum and possibly Verticillium dahlia. Species and races of the fungus a lot, but the strawberries are parasite specific. In General, for Verticillium there are more than 300 host plants, that is forage. This vegetables, fruits, shrubs, flowers and weeds, field crops – so wide list of affected plants.
If the fungus appeared in the soil, it can live in it for 25 years and longer, if there are susceptible weeds in this area. The new lines moved with the soil on the tools and shoes, with seeds from sick plants.
Factors contributing to the spread of the disease
Temperature range from +12°C to +30°C; optimal for exciter: +21…+24°C. he likes the change of weather when cool cloudy days are mixed with warm Sunny days.
In such suitable conditions, hyphae (organs of the fungus) penetrate into the root hairs, and if they have wounds the infection proceeds more actively.
Complex of symptoms
The first symptoms are very similar to frost damage, blight and black scurf on potato roots. The best way diagnostic laboratory, however, to distinguish diseased plants can be and on external signs.
Three roots on the left belong to susceptible to verticillate plants, two on the right – plants which are resistant to this disease.
- all organs are affected: vascular system, root neck, roots, rosette;
- small leaves with chlorosis are visible in the middle of the Bush;
- the plant appears reddish-yellow in color;
- visible necrosis of leaf edges;
Bush crouches like: he is losing height because the leaves begin to fly from the center of the outlet on the radii of the stalks – it turns out almost round.
- vessels change color to brown (as seen on the cross section), on stalks and mustaches sometimes appear brownish or bluish stripes and spots;
- on new roots blacken tips;
- young leaves can wither and develop along the Central vein;
- the growth of berries is the time when the disease becomes especially noticeable; the peak falls on the middle of July, if the plants are not killed;
- for the surviving or remaining healthy plants until frost may manifest signs of the disease.
Serious trouble: the death of the mother plant and mustache with a new outlet, but one young plant survived. It’s sick, but there’s no symptoms.
Prevention of strawberry vertical wilting
- grow on fertile, well-drained soils;
- ensure the outflow of excess water to avoid its stagnation;
- remember that on sandy soils plants can die in a few days;
- do not give extra nitrogen fertilizers to boost growth;
- five years before planting strawberries so organize crop rotation on the site, so that future strawberry ridges do not grow potatoes, eggplants, tomatoes, peppers, melons, blackberries;
- grow tolerant or resistant varieties of strawberries;
- do not plant in place of growing roses and chrysanthemums.
On industrial plantations before planting, the soil is treated with fungicides.
So as not to introduce the pathogen into the soil with your hands, you need to carefully consider the choice of young rosettes, delete all suspicious (possibly asymptomatic) plants. It is necessary to regularly destroy nematodes, weeds. It is believed that broccoli is not susceptible to the disease, so you can grow this culture as a fumigant, that is, with its help to disinfect the landing area, as the number of pathogens in the soil decreases.
Vertical withering of raspberry
This microscopic pest has not bypassed its attention to raspberries, but black it is more inclined than red. Can infect and BlackBerry, but heavy losses in the war with the enemy, as a rule, does not happen. You can observe the defeat of new shoots with a lack of irrigation in hot dry weather.
If there are black and red raspberries on the site, then the disease will first appear on the black, and in a month (approximately) – on the red. The symptoms are:
- lower leaves become more dull than the top;
- the process goes to the top of the shoots, sometimes the leaves remain only at the top;
- the escape itself seems to dry up.
On the shoots of black raspberries there is a blue-purple stripe from the soil level, but not necessarily to the top of the branch. See, that’s how young black raspberry shoots wither.
On red raspberries the strip may not be, or it is unmarked. This is how the stripes look on the young shoots.
In spring, infected shoots are most often killed. If left alive, it will be flawed:
- poor development and shriveled kidneys;
- young leaves on last year’s shoots stunted and yellow;
- escape dies before the berries ripen;
- the berries themselves dry.
The causative agent affects plants of different species, so all methods of working with the soil, processing fungicides, the same as for strawberries.