What to do if strawberries have leaves in a hole?
The appearance of small holes on strawberry leaves is a fairly common and unpleasant phenomenon. It is not seasonal and can occur throughout the growing season. The age of the plant is also not an obstacle to the appearance of holes, which is why both young and mature plants are equally susceptible to perforation.
Causes of holes on the leaves
Leaky leaves are the result of the harmful activity of pests or appear as a result of plant disease. In rare cases, the cause of holes can be mechanical damage to the sheet plates. This occurs as a result of strong winds or exposure to large hail. However, in this case, the shape and size of the holes will be rather ragged and uneven, and it is extremely difficult to confuse them with holes of biological origin.
Diseases
The cause of the appearance of holes are fungal diseases. Most often, strawberry shoots are subjected to dendrophomosis, ramularia and anthracnose. All three diseases are varieties of a fungal disease, popularly referred to as spotting.
- Anthracnose or black spot (lat. Colletotrichum Acutatum Simmonds) with a dangerously long incubation period and damage to the entire plant at once. This is due to the fact that fungal spores can be easily carried by the wind to neighboring plantations, infecting more and more shoots.The first sign of the disease is the appearance of dark tan marks, similar to a burn or ulcer. Over time, the damaged areas dry out, crack and spill out, forming numerous holes instead. The most favorable environment for the causative agent of the disease is hot and humid weather. In addition to the air way, infection of plants can occur through infected equipment, seedlings and water.
- brown spot also often found in strawberry plantations. The disease begins with the appearance of poorly visible spots, which quickly acquire a reddish-brown color and rapidly spread over the surface of the leaf. Over time, the spots acquire a brown tint, dry out and spill out, forming holes. In addition, the spots often grow and merge, resulting in an almost complete defeat of the leaf blades and their death.
- Dendrophomosis (brown spotting) in terms of features, it is quite similar to brown spotting, with the only difference that its spots are often angular in shape. The disease manifests itself in July-August and is often provoked by a large amount of rain. The disease significantly reduces the immunity of plants and makes them most vulnerable to viral and infectious diseases.
- White spotting or ramulariasis also has a fungal nature and is characterized by the appearance of white, with a bright brown border, spots that dry out and crumble over time. At the beginning of the disease, the spots have a brownish tint and are small in size. Over time, the middle of the spot turns white and crumbles, leaving behind a hole. Fungal spores are highly survivable and capable of spreading in any weather.However, when watering strawberries with cold water, the likelihood of an ailment increases. The disease can appear at any stage of plant development, including early spring, when the leaves are just beginning to appear.
With a particularly strong damage to plants by ramularia blight, the crop can be completely lost. In addition to the leaf cover, all above-ground parts of the plant are susceptible to white spotting, including mustaches, peduncles and petioles.
Pests
However, not only diseases are the cause of the appearance of holes: very often perforation and death of the leaf cover occurs due to the fault of insects.
- Raspberry strawberry weevil (lat. Anthonomus Rubi) is a small black-brown beetle, reaching 3 mm in length and feeding on strawberry leaves, flowers and buds. The female weevil overwinters in the foliage and, with the appearance of the first spring peduncles, begins to lay eggs. One egg is laid in each bud, and in a season one individual is able to make 50 such clutches. Young insects are born in June and immediately begin to devour strawberry foliage. The bugs gnaw through small, even holes in it, which are visually easy to distinguish from various kinds of spotting and other diseases.
However, an experienced gardener will notice the appearance of the weevil long before the defeat of the leaves. The first signs of the presence of insects on the bushes are a black eaten peduncle. If you do not take emergency measures to destroy the pest, then the entire plantation will acquire the effect of delicacy, which occurs as a result of the mass and rapid destruction of leaf cover by beetles.
- nettle leaf weevil (lat. Phyllobius Urticae Deg) is a brightly colored green beetle, the length of which can reach 12 mm.The main type of pest food is young strawberry leaves, which are devoured by them figuratively and on the sides. The insect lays many eggs, which pupate during the budding of plants. The first sign of the appearance of a pest is the fall of the buds. In addition to devouring the above-ground part of the shoots, beetle larvae also eat the root system, which causes even more damage to the plant than adult pests.
- strawberry leaf beetle (lat. Pyrrhalta Tenella) is an extremely voracious dark brown beetle, reaching a length of 4 mm. The pest begins its eating of the leaf by gnawing holes, after which it enters the taste and completely destroys the leaf blade. Only the veins and part of the upper film remain intact. The insect is quite prolific and is able to lay about 200 eggs per month. The eggs are fixed on the underside of the leaf blades, and after a couple of weeks, larvae appear from them. Before the period of pupation, the larvae actively devour the leaf mass, after which they turn into pupae and move to the upper layer of the earth. After another couple of weeks, young bugs appear from the pupae, which also begin to feed on strawberry leaves or what is left of them after finding the larvae on them.
However, leaf beetles have natural enemies in nature, which are ground beetles and bugs. Due to the presence of these insects, the number of leaf beetles is regulated and population growth is somewhat curbed.
- Strawberry leaflets (lat. Peronea comariana Zell) are reddish-brown butterflies with a wingspan of up to one and a half centimeters. Caterpillars devour young strawberry leaves, and butterflies gnaw small holes in them, turn them into tubes and entangle them with sticky cobwebs.In addition to strawberry leafworms, other types of caterpillars often parasitize on strawberry bushes: currant leafworm and winter moth. The main difficulty in dealing with caterpillars is their negligible size, which makes it extremely difficult to notice the presence of parasites.
Treatment
If small or large holes are found on strawberry leaves, there is no need to panic. Any gardener can help plants cope with diseases. To do this, be patient and do everything as experienced agronomists advise.
- Black spot or anthracnose is successfully treated with fungicidal preparations. However, when the disease is advanced and a significant part of the leaf cover is affected by the fungus, the only effective measure is the removal and burning of the infected parts.
- Brown spot or dendrophomosis is also treated with fungicides and insecticides. A good effect is observed after using "Ridomil", "Falcon", "Topaz" and "Diskor".
- With the appearance of white spotting, not only the aerial part of the plant, but also its roots need to be treated with fungicidal treatment. Spraying should not be done during flowering and fruiting. In the spring, plants are recommended to be treated with a solution of potassium permanganate. With extensive damage to the leaf cover, perforated leaves must be cut off and burned. In case of damage to both the ground part and the root system, the plant is subject to complete destruction. Infected land is treated with fungicides and is categorically not suitable for planting strawberries in the next 6 years.
During this period, onions, garlic, dill or parsley can be grown on the plantation, and green manure is planted in the spring before planting strawberries.
Pest control should start as early as possible.The appearance of even single holes often means that someone is chewing on the plant. Therefore, appropriate treatment must be carried out much earlier than the insect destroys the plant. The first drug that enters the battle with pests should be 3% karbofos. In the event of a massive invasion of insects, plants are sprayed with Karate, Fitoverm, Corsair or Cesar.
If pests are found after flowering, the use of chemicals should be discontinued. In this case, biological means or folk methods are used. Good results are obtained by the use of a garlic solution, for the preparation of which half a glass of crushed cloves is poured with a liter of water at a temperature of 30 degrees. Next, the jar is hermetically sealed and cleaned in a warm place for 12 hours. After the specified time, the solution is filtered and diluted with five liters of cool water. Spraying should be done in the morning or evening hours in dry weather.
Additional measures to combat insect pests are off-season digging of the soil, as well as timely weeding and loosening. With a slight defeat of the leaf plates, tobacco dust helps.
Prevention
The main preventive measure is the acquisition of healthy seedlings and thorough disinfection of the soil before planting. In addition, watering plants should only be done under the root. Drops of water on the leaf plates are undesirable. And it is also necessary to follow the rules of crop rotation, not to grow strawberries in one place for more than three years.
Before flowering, the bushes must be treated with a 1% solution of Bordeaux liquid. This will prevent the appearance of not only various kinds of spotting, but also other fungal diseases.The treatment of shoots with Fitosporin, carried out in early spring, also helps well. It is recommended to sprinkle the earth around the bushes with wood ash, but the introduction of fresh manure, on the contrary, is highly undesirable.
Throughout the growing season, it is necessary to monitor the condition of the leaves, and if the slightest signs of perforation are found, immediately take measures to treat the plants.
For information on how to treat strawberries for diseases and get rid of pests, see the following video.