Author: Elena N. https://floristics.info/ru/index.php?option=com_contact&view=contact&id=19 Category: Fruit and berry plants Published: July 30, 2015Last edits: November 02, 2020
- Protecting strawberries from birds
- Spring treatment
- What to feed
Both children and adults love to eat strawberries, so the demand for this berry on the market is consistently high every year. But sometimes amateur gardeners complain that the berry harvests are not as good as before, that the strawberries have been attacked by some kind of disease from which there is no escape. Sometimes the cause of a bad or spoiled harvest is insects, whose destructive activity is not immediately apparent. We will talk about diseases and pests of berries and how to protect strawberries from them in this article.
Botanical description
Homemade strawberries are a herbaceous perennial garden plant, as popular in our gardens as raspberries, currants and gooseberries. A close relative of the strawberry is the wild strawberry. Strawberries, thanks to their unsurpassed taste, are cultivated in Europe, North and South America. The strawberry stem is erect, from 15 to 40 cm high, large trifoliate basal leaves of the strawberry, collected in a rosette, consist of ovate-rhombic leaves, wide-toothed along the edge, on short petioles. Both the stem and leaves of the strawberry are covered with glandular hairs. Large strawberry flowers with a diameter of up to 2.5 cm in quantities from 5 to 12 pieces make up a corymbose inflorescence.
What is commonly called a strawberry - a juicy red cone-shaped fruit - is actually an overgrown receptacle on which there are real strawberry fruits - small nuts. Garden strawberries have three times more chromosomes than wild or green strawberries, so they are not cross-pollinated with any other species. Strawberries are poorly transported and do not last long when fresh.
Strawberries are more likely than berries introduced into cultivation not so long ago, such as blueberries and blackberries, to be infected with fungal diseases and attacked by pests, but proper planting and care of strawberries ensures that these risks are kept to a minimum.
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Infectious diseases
But most often strawberry leaves turn black around the edges due to various diseases. Which can still be aggravated by violations of agricultural technology and pest attacks.
Gray rot
A very unpleasant fungal disease of strawberries and wild strawberries. In a diseased plant, the leaves look dried out and acquire a brown tint. The berries on the infected plant rot, becoming covered with white fluff of fungal sporangia. When touched, spores are released.
Appears with prolonged waterlogging and relatively low air temperatures. Especially when strawberry plantings are thickened by weeds.
Verticillium wilt (wilt)
Dangerous fungal disease. Affects the vascular system of the plant. As a result, the bush weakens significantly. This disease can also cause strawberry leaves to turn black and dry out. At the first signs of the disease, you can treat with fungicides based on copper preparations or Fitosporin , Fundazol, etc. In case of severe damage, it is better to dig up the plant and burn it.
Strawberry diseases and their treatment
Strawberries are withering
If strawberry bushes quickly lose turgor and wither, the reason may be insufficient or infrequent watering. Most often this is noticeable during the period when strawberries grow green and after fruiting. Water your strawberries in the morning or evening and don’t skimp on the water. But if the strawberry does not lack moisture and nevertheless withers, this may be the result of damage to the root system - mole crickets or moles, making passages in the ground, undermine and gnaw the roots of the strawberry, and sometimes even push the bushes out of the ground. This is what causes strawberries to wilt.
We wrote about the fight against moles in an article devoted to apple tree diseases. In the fight against mole crickets, insecticides are used, placing them in the hole when planting strawberries. If you haven’t thought of doing this, dig trapping holes up to 50 cm deep in the area and fill them with not completely rotted horse manure, and sprinkle earth on top - mole crickets accumulate in this hole over the course of the season, intending to spend the winter in it. In late autumn, manure is used to fertilize the site, and the mole cricket is destroyed.
Strawberries that have contracted Fusarium, Phytospora or Verticillium wilt also wilt. The same symptoms attract attention when strawberry roots are affected by rot.
Why do strawberries dry out?
Sometimes drying is the next stage after wilting, the causes of which we described in the previous section, but more often strawberries dry out as a result of damage to fungal diseases: spotting, late blight or gray rot, verticillium wilt, powdery mildew. Carefully inspect the area with strawberries: if only a few bushes are affected, remove and burn them, but if the infection is more extensive, treat all plants in the area with fungicides.
There are times when strawberry greens look juicy and healthy, but the berries suddenly begin to dry out. This happens when the bushes are affected by gray rot at an early stage of fruit formation - this is why the berries of strawberries dry out and do not rot. Make it a rule to carry out spring and autumn treatment of strawberries against diseases and pests, and you will not have to wonder why strawberries dry out and how to save strawberries from diseases.
Strawberries are rotting
Why do strawberries rot? There are various reasons for this. Strawberries rot when they are affected by rot - root, black or gray, caused by fungi and provoked by too high humidity. For information on how to deal with these diseases, see the appropriate section. Sometimes strawberry bushes suffer from cramped conditions and poor ventilation, and with high humidity this leads to rotting of the berries. Remove fruits affected by rot, and for preventive purposes, as soon as ovaries appear on the strawberries, mulch the strawberries over the area with sawdust so that the ripening fruits do not come into contact with the soil and do not rot.
Strawberries turn yellow
There is no clear answer to the question of why strawberries turn yellow, since there are always several reasons. Sometimes strawberry leaves turn yellow due to a lack of nitrogen and magnesium in the soil. If there is a lack of magnesium, add magnesium sulfate to the soil in dry form, followed by watering the area or in the form of a solution for several weeks in a row, since there is only 10% magnesium in this fertilizer. Dolomite flour is also a source of magnesium. If there is a lack of nitrogen, add nitrogen-containing mineral or organic fertilizers to the soil, and in the future, fertilize strawberries with nitrogen fertilizers every spring, and start doing this even before the strawberries begin to grow.
Strawberry leaves turn yellow, even to a lemon tint, in the case of strawberry disease with non-infectious chlorosis, when the roots sitting in unheated soil are not able to supply the leaves with as many nutrients as required for the growing season. This reason can be eliminated by foliar fertilizing of strawberries with iron-containing preparations and watering the area with warm water.
Another cause of yellow leaves is the viral disease xanthosis (mosaic, jaundice), spread through infected planting material or aphids. There is no cure for it, so in this case preventive measures are of particular importance - spring and autumn preventive treatment of the area with a one and a half percent solution of nitrafen or two to three percent Bordeaux mixture.
Strawberry leaves are turning red
If strawberry leaves turn completely red closer to autumn, then this is an absolutely natural process, but if redness appears in the form of spots, then this is a sign of the fungal disease septoria, or white spotting. Sometimes this is how strawberries react to too acidic soil - add dolomite flour to the soil, and the problem will disappear.
Why doesn't it bloom
And there are several answers to the question “why strawberries don’t bloom.” If extreme heat lasts longer than two weeks, strawberry flowering is noticeably reduced. Strawberries may not bloom if you replanted them at the wrong time - rooting the bush takes time and effort, and there is no time for flowering. An overdose of strawberries with nitrogen fertilizers leads to the fact that they are intensively overgrown with green mass, but alas, to bloom! - doesn’t want to.
There is another reason: strawberry varieties have appeared with properties similar to weeds. The bushes of these weeds look strong and healthy, but do not bloom; in addition, by reproducing vegetatively, they choke and crowd out fruit-bearing bushes. If you notice that a bush is taking too long to bloom, remove it ruthlessly.
Spots on strawberry leaves
When reddish-brown spots form on the leaves, and then the strawberry leaves lighten and only the border around the spot remains red, you are dealing with septoria, which we will write about in more detail in another chapter. Brown-brown spots without a clear outline, in the early stages of the disease, similar to opaline marks - this is brown spotting. Read about how to deal with leaf spots in the next section.
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Spotting
All strawberry diseases can be divided into three groups:
- leaf spots;
- fruit rot;
- withering.
In this chapter we will introduce you to the first risk group. White spot, or septoria, appears as dark red spots that turn white in the center over time. Sometimes white spotting of strawberries and wild strawberries is called another disease - ramularia, the symptoms of which also look like white spots with a purple border, which merge with each other over time, and the whitish parts of the leaf crumble, and holes appear in their place. And, finally, brown spotting - the edges of the leaves affected by this disease seem to be scorched, then the “burns” spread over the entire leaf and leathery dark-colored pads are formed on the upper side of the plate - mycelium.
All these spots are of fungal origin, so the methods of dealing with them are identical. As a preventive measure, spring treatment of the area with phytosporin or other fungicide is used. As a treatment, strawberries are treated with copper oxychloride or one percent Bordeaux mixture during the period of leaf growth, before flowering and after picking the berries. A prerequisite is to treat not only the upper side of the leaves, but also the lower side. Don't let the strawberries grow too much - the fungus spreads faster in dense plantings. Remove weeds and strawberry weed varieties from the site in a timely manner.
Gray rot
This fungal disease can destroy up to 80% of the crop in one season. First, fast-growing dense light brown spots, covered with a fluffy coating, form on the berry, then the affected fruit and strawberry stalk dry out, and the leaves become covered with dark gray or brown spots without clear outlines.
Strawberries also suffer from black rot, which is very similar in symptoms to gray rot, but the strawberry leaves turn black rather than gray soon after spots appear on them.
The fight against gray rot, as well as black rot, begins with the spring preventative treatment of strawberries with a two to four percent solution of Bordeaux mixture. All parts of the plant affected by rot must be removed. If the plant is severely affected, remove it entirely. Do not use the plant residues of these plants to prepare fertilizers, but burn them so as not to spread the fungus throughout the garden. Maintain crop rotation, do not allow strawberry plantings to become overgrown, regularly pull out weeds, and before fruiting, mulch the soil in the area with sawdust or straw so that the ripe berries do not touch the ground. In the fall, carry out another preventive treatment of the area with strawberries with Bordeaux mixture.
Fusarium wilt
Fusarium disease manifests itself as necrosis on the edges of the leaves, gradually covering the entire leaf blade and petioles, as a result of which the rosette falls apart, the leaves droop, and the bush dies in one and a half to two months.
Phytospora wilt, or redness of the axial cylinder, can be chronic or transient, but one way or another the bush lags behind in development, the leaves acquire a dirty gray tint and curl up in the shape of a bowl. The fibrous roots of strawberries are dying. The death of the bush occurs within 2-3 years.
The difference between verticillium wilt and fusarium or phytospora wilt is that the old leaves wither first, and only then the younger ones and the entire bush. Verticillium affects the root system, as can be seen from the petioles of the leaves - their base acquires a red-brown tint. Plants that receive nitrogen fertilizers in excess are most easily affected by Verticillium wilt.
In order to avoid these troubles, it is necessary to comply with agrotechnical requirements, in particular, observe crop rotation and not grow strawberries in areas where crops that are not resistant to wilting previously grew. Before planting, treat the strawberry roots with a solution of biological preparations such as agate 23k at a concentration of 7 g of the drug per 1 liter of water, and if signs of disease are detected, treat the strawberries through a drip irrigation system with preparations such as quadris, metaxyl, ridomil. Do not neglect preventive treatment of strawberries at the beginning of the growing season and when preparing the site for winter.
The most common reason: violations of agricultural practices
Strawberry leaves can dry out around the edges for the most banal and simple reasons. The simplest and most non-threatening is the banal death of old leaves. For example, leaves with which the bushes overwintered in the spring or are opened at the beginning of summer. This is a normal, natural process. The same thing happens at the end of fruiting, when spring leaves begin to die.
Another option for drying out the edges of strawberry and strawberry leaves is a lack or excess of moisture. Strawberries love water, so if there is a lack of it and during the summer heat, the leaves may begin to dry out. But it also happens the other way around - excess moisture can cause the plant’s leaves lying on the ground to rot. Everything can be corrected by normalizing watering.
Strawberry leaves can also turn black around the edges due to sunburn. They arise from the action of the hot summer sun on the foliage with droplets of water. The moisture droplets act like little magnifying glasses and concentrate the sun's energy. The result is burns and drying out.
Another reason why the edges of strawberry leaves dry out is the lack of nutrients. For the normal development of a berry plant, micro and macroelements are needed. If there is a lack of phosphorus and potassium in the soil, the edges of the leaves of strawberries and strawberries can also dry out. This can be corrected by feeding the berry garden.
Strawberry pests and their control
Protecting strawberries from birds
Not only strawberry diseases pose a threat to the harvest, but also other factors - unexpected weather changes, rodents, snails and slugs, insect pests of strawberries, as well as birds that fly into strawberry beds and peck at the largest juicy berries. There are many ways to scare birds away from strawberry beds. We offer you two proven and proven solutions to this problem:
- bird netting on strawberries: you need to drive pegs about a meter high around the perimeter of the area and here and there between the rows and throw a fine net over them;
- New Year's tinsel: drive meter-high pegs along the edges of the area, stretch twine between them along the perimeter of the area and often hang New Year's "rain" on it - the lightest breeze makes the Christmas tree rain sway and sparkle, and this scares away the birds.
Slugs on strawberries
Naked slugs are a serious problem that can be difficult to deal with. If left to chance, they can completely destroy a plot of strawberries in one season. But you can prevent the appearance of slugs: make a ditch around the area and fill it with lime, tobacco, ash or ground pepper - this is an insurmountable barrier for slugs crawling from outside. If you have noticed the appearance of gastropods, try to defeat them by using dry fertilizers - superphosphate or potassium salt, scattering them around the area at dusk (slugs are nocturnal). The preparations irritate the surface of the mollusks, and they begin to produce a large amount of mucus in order to shed the irritating substance along with it, so after 30-40 minutes, fertilizers should be scattered over the area again.
Drugs such as Thunderstorm or Meta radically eliminate slugs, but the slug dies only if the drug comes in contact directly with it. You can mulch the beds with a transparent film, under which the slugs die, unable to withstand the “steam room”.
Weevil on strawberry
Sometimes you can see pedicels on strawberry bushes without buds, and the mark on them looks as if someone had cut off the buds. This is how the strawberry-raspberry weevil damages strawberries - a grayish-black bug up to 3 mm long. The bugs overwinter under fallen leaves and between clods of earth, and in the spring their females lay eggs in the buds of strawberries, raspberries or wild strawberries, gnawing the stalk under the bud. One female can destroy up to 50 flowers, and more often the weevil for some reason damages male flowers on high pedicels. The weevil larva eats the bud from the inside, where it pupates, and in July a new generation of weevils hatches, devouring strawberry leaves and settling in the ground for the winter.
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The fight against weevils on strawberries is carried out by treating the bushes with Karbofos, Metafos, Actellik, Corsair and other preparations of similar action in accordance with the instructions during budding, but no later than a week before flowering. As a preventive measure, spring and autumn treatment of the area on a windless day with Actellik or Zolon is suggested.
Bugs on strawberries
The strawberry leaf beetle is a yellow-brown bug up to 4 mm long. It and its larvae eat strawberry leaves, and if there is a massive infestation of beetles, they can destroy the greenery throughout the entire area. Spring treatment of strawberries and the soil around the bushes with actellik, corsair or karbofos greatly reduces the likelihood of this pest appearing. In addition to the weevil and leaf beetle, strawberries are damaged by the cockchafer, or beetle, as it is also called. It eats the leaves of plants, including strawberries, for several weeks during the summer and reproduction period, and sometimes there are too many beetles. And the worst thing is that female beetles lay eggs, from which larvae develop that can cause even more serious harm.
Adult beetles have to be dealt with using old methods - shake them off the branches in the evening or in the morning, before the air temperature rises above 15 ºC, and destroy them mechanically so that they do not lay offspring. You can arrange a light trap for the cockchafer: coat the edges of the basin with a sticky substance (solid oil, for example) and place a light source at the bottom, take the basin out into the garden at dusk and wait for the beetles to fall into the basin, from which they cannot get out.
May beetle larvae
Incredibly voracious larvae of the cockchafer gnaw at the roots of strawberries. Why strawberries! A three-year-old beetle larva can eat the roots of a two-year-old pine tree in one day. Khrushchev larvae can also be collected manually and then destroyed, but it is best to water the area with strawberries during the growing season with an infusion of onion peels: fill the bucket one-third with onion peels, then fill the bucket to the top with water and leave for 5 days, and then dilute the infusion with another a bucket of water.
The best remedy for larvae is the biological drug Nemabact, which selectively destroys soil pests. The effectiveness of this drug is 90%, but since it contains living organisms, when purchasing, check the conditions and shelf life of Nemabact.
Mites on strawberries
Strawberries are parasitized by two types of mites - spider mites and strawberry mites, and both of these species feed on the juice of strawberry leaves, as a result of which the strawberry leaves curl, dry out and fall off. In order to destroy these pests in the spring, as soon as young leaves begin to grow, it is necessary to treat the area with phosphamide, karbofos or metaphos. In case of severe damage, re-treatment is carried out on the eve of strawberry flowering. Ticks will die if you pour a hot (65 ºC) light pink solution of potassium permanganate over the strawberries in the evening.
But do not forget that the main reason for the appearance of spider mites is a lack of moisture, and the strawberry mite enters the area along with the seedlings, so water the strawberries regularly, and when purchasing seedlings, inspect them carefully. When the time comes to plant strawberries, immerse the seedlings in hot water (47-48 ºC) for 15 minutes - this will rid the seedlings not only of mites, but also of nematodes.
Nematodes
The length of the strawberry nematode is no more than one millimeter, so it is very difficult to detect it with the naked eye, especially since it lives in the buds and axils of leaves. In one season, up to eight generations of nematodes destroy strawberries. As a result of their vital activity, the buds and peduncles thicken and shorten, the petioles of the leaves become bare, red and thin, the leaves darken and become leathery. The nematode enters the area along with infected seedlings, but due to the small size of the nematode, it is difficult to detect. If the occupation of strawberries by a nematode is confirmed by characteristic symptoms, carry out heat treatment of the affected bushes, as described in the previous section, just try to spray the strawberries so that the hot solution gets to all parts of the plant. It will be even better if you heat-treat the purchased seedlings - just in case, as they say, in case of emergency.
Ants
Ants in the garden are a nuisance, even though they probably provide some benefit. However, there is much more harm and discomfort from them. In addition, if ants appear in the garden, aphids will appear after them, which, as you know, is a pet of the anthill. There are many means of getting rid of these insects - both traditional, biological and chemical, but they all have drawbacks. Today, the best way to get rid of ants are special bait traps with slow-acting poison. The ants deliver these poisonous baits to the anthill and feed it to their queen and other ants, so that within a day the population begins to die en masse. The range of such traps in specialized stores is quite wide, so you can choose among them the one that suits you.
How to treat strawberries - prevention
Spring treatment
If in the spring you find that you have a lot of dry bushes in your area with strawberries, this is your signal to change the area, because it is undesirable to grow strawberries in one place for more than four years. What actions does it take to care for strawberries in spring? Remove the top layer of soil between the bushes, in which pest larvae and pathogens overwintered, and replace it with fresh soil. But if you cannot do this, then remove last year’s rotted mulch from the area and at least loosen the soil in the area to a depth of 6-8 cm, while removing weeds. Cut off all old leaves, tendrils and peduncles, plant young rosettes in place of dead bushes and add fertilizer to the soil, and also treat the area against pests and diseases - there should be at least three such treatments in the spring.
Treatment during flowering
As soon as the strawberries begin to grow, mulch the area with organic matter or special film. Just before flowering, carry out another treatment of strawberries against fungal diseases and pests. When buds begin to appear, add phosphorus fertilizers to the soil, and after flowering - complex mineral fertilizer.
Treatment for diseases
The older the area, the higher its infectious background, so it is impossible to avoid diseases without chemical treatment of the area. On average, strawberries are sprayed three to four times per season: the first - in early spring after harvesting the area with a two to three percent Bordeaux mixture or other copper-containing preparations, then in early April, before flowering, when the leaves begin to grow en masse, the strawberries are sprayed with Topsin-M, Quadris or other fungicide. The third and fourth treatments with fungicides are carried out after flowering at an interval of two weeks.
Strawberry pest control
We told you how to deal with various insects that damage strawberry bushes. Preventive treatments are carried out in the spring, after you have replaced the top layer of soil on the site. The best drugs to use are actellik, karbofos, metafos and other drugs of similar action. The new drug Tiovit-Jet has proven itself to be excellent - an acarofungicide that copes with both pests and fungi.
The edge of the sheet darkens or rusts
Often, yellow spots in the shape of an oval or circle are found on the inside of strawberry leaves. At first, the spots are small and unnoticeable. However, the disease gradually progresses . The edges of the spots appear rusty and their volume increases. In appearance, the mushroom resembles mold, only with eye-catching colors.
Strawberry diseases
Failure to take action provokes the fusion of orange papules, which completely cover the leaf and take nutrients from the strawberry. As a result, the foliage falls off and the bush dies.
If the first manifestations of the disease are detected, it is important to promptly treat the seedlings with antifungal drugs. Otherwise, the entire harvest may be lost.
How to resist:
- Spread polyethylene under the diseased bush. In this way, strawberries are protected from spreading spores to other seedlings.
- Wearing gloves, carefully trim the affected leaves (to the root).
- After the operation, the foliage is destroyed away from the strawberry beds.
Attention! It is prohibited to dig up or throw away leaves with rust. The fungus overwinters well in the soil and again infects healthy strawberries.
How to fight
Treatment of strawberry bushes with special means is required:
- Titanium;
- Baktofit;
- Agromedicine.
Most summer residents note the productivity of fungicides. However, it is good to keep safety in mind.
To protect strawberries from rust, the crops are treated in the spring with Bordeaux mixture (1%).
Fertilizing strawberries
What to feed
The first fertilizing of strawberries is carried out in warm weather, after pruning the strawberries and harvesting the area, before the leaves begin to bloom - that is, in April-early May, apply highly diluted bird droppings (1:12) or complex mineral fertilizer - a spoonful of nitroammophoska for 10 liters of water. At the beginning of flowering and fruit ripening, strawberries require more potassium, so fertilizing should consist of an infusion of chicken manure or potassium nitrate; the Kemira-universal complex mineral fertilizer has proven itself very well.
After the strawberry harvest, a fourth feeding is carried out, which accumulates plastic substances for the next harvest. Top dressing should consist of a solution of phosphorus-potassium fertilizers: 30-40 g of superphosphate and 20 g of potassium fertilizer are dissolved in ten liters of water.
Strawberries also need foliar feeding in the form of spraying the leaves in August with a three percent urea solution for successful formation of flower buds for the next year and spraying strawberries four times with a boron solution every 3-4 days during the flowering period - this treatment helps to increase the number of ovaries and the size of future berries.
In addition to the listed fertilizers, in specialized stores you can buy balanced fertilizers developed specifically for strawberries, the use of which increases the yield of the berry by 30%.
