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Experienced gardeners know that holes in cabbage are a sign of pest damage to the vegetable. And if protection measures are not taken in a timely manner in this case, then you can lose the entire crop. After all, the holes that appear subsequently begin to rot, and this leads to premature damage to the head of cabbage. However, before taking any measures, it is necessary to figure out which pest could cause their appearance. Otherwise, the applied control measures may be useless.
Holes on cabbage disrupt metabolic processes in plant tissues
Why did holes appear on the cabbage
There are several types of insects that can cause holes in the heads. In this case, you can determine the type of insect by the shape, size, and even shade of the hole. Therefore, it is worth considering all possible options in order to accurately determine the cause of damage.
Slugs
With the invasion of slugs, rather large holes appear on the cabbage leaves, which have an irregular shape. Also a characteristic feature of this pest is the presence of mucus on the surface of the plates, which they leave in the process of movement. Moreover, you can notice this even when it dries up, since in this case there is a silvery tint, which is noticeable even at a distance with the naked eye.
When cabbage is damaged by slugs, holes appear randomly on the entire surface of the leaves. Damage sites are an excellent environment for fungal, viral bacteria. In the future, this causes rotting of the head of cabbage. Therefore, this pest is considered the most dangerous for cruciferous crops.
Slugs become active in high humidity
Cruciflo flea
This insect is a member of the leaf beetle family. The cruciferous flea beetle is a small beetle with long whiskers, whose body length barely reaches 3 mm. The pest has a black or dark green color, it is also possible to have stripes with different edging.
Females lay eggs in the soil as soon as the air temperature rises above +15 ° C in spring. Two weeks after this, larvae appear that feed on the roots of young cabbage seedlings. Subsequently, they move to the leaves of the plant, as a result of which holes appear. The first sign of damage to cabbage by a cruciferous flea is superficial holes on the plates, which subsequently become through and become widespread.
Immature seedlings of cabbage during the invasion of the cruciferous flea die for 2-3 days
Cabbage butterfly caterpillars
When cabbage is damaged by cabbage butterfly larvae, holes also appear on the leaves of the plant. The caterpillars of the pest are large in size and reach 3,5 cm in length. Their body is elongated, yellow-green in color, covered with black dots and hairs. A characteristic difference is three yellow longitudinal stripes on the sides.
The larvae of the pest feed on the soft tissue of the leaves. After them, only veins remain. Also, when the caterpillars invade, a sticky coating appears on the bottom of the plates.
Caterpillars of cabbage butterflies are particularly gluttonous
cabbage fly
This is another malicious pest of all cruciferous crops. In appearance, it looks like an ordinary fly, but its body size reaches 1 cm. Active years of insects begin in early May, and then in mid-June. At this time, the cabbage fly lays eggs on cabbage leaves, from which small light larvae appear after 7-10 days.
The young growth of the cabbage fly actively feeds on the leaves and the root system of seedlings. This leads not only to the appearance of small rounded holes on the plates, but can also provoke the death of plants.
The fly is activated when the air temperature is above +18 °C
Caterpillars of cabbage scoops
Cabbage becomes full of holes even when it is affected by scoop larvae. They are green or brown caterpillars, up to 1,5 cm in size. After emerging from the eggs that the butterflies lay, the larvae begin to actively feed, making neat round holes in the cabbage leaves. Subsequently, they turn into passages that lead inside the head of cabbage.
The scoop is fertile, but its adults do not damage the cabbage. During the season, 2-3 generations of the pest appear. The larvae overwinter in the soil at a depth of 10 cm. And in the absence of control measures, they quickly spread and damage all plantings of cruciferous crops.
Scoop larvae destroy up to 20% of the crop
Cabbage aphids
A small insect of a gray-green hue, which allows it to go unnoticed on cabbage for a long time. Aphids are characterized by an accelerated rate of reproduction, so soon a whole colony of this pest appears on the affected plant. The insect feeds on cabbage juice, so bright spots initially form on the affected areas, which subsequently turn into necrotic spots, and then holes.
You can detect cabbage aphids at the initial stage by twisting the plates and a sticky coating on their surface. Also a sign of the appearance of this insect on the site are ants scurrying around, which feed on the sweet span secreted by insects.
Cabbage aphids are carriers of 20 types of viruses
What to do if cabbage leaves are in holes
If the leaves of Beijing, white or other cabbage have become in a hole, then urgent measures must be taken to save the cabbages. Otherwise, this will lead to a lack of harvest not only in the current, but also in subsequent seasons.
To combat pests, you can use mechanical and agrotechnical methods, folk remedies, chemicals. But it should be understood that only with the complex processing of cabbage can the desired result be achieved.
Folk remedies
This method of control is relevant with a small number of pests and as a preventive measure. Folk remedies are prepared on the basis of available components.
The most effective of them if holes appeared on the cabbage:
- Celery. The tool helps against cabbage flies, aphids. To prepare it, you need to chop 4 kg of celery stalks, add 10 liters of water and boil the mixture for two hours after boiling. Then leave the solution for five hours, and then clean and add 2 liters of water. Use for spraying every five days if the first holes appear on the leaves.
- Wood ash. Treat plants with this component if holes from snails and slugs appear on the cabbage. It must be used dry. For processing, it is necessary to sprinkle wood ash at the base of the cabbage and over the leaves. Carry out the procedure every time after rain or watering, until new holes stop appearing.
- Soda ash. This tool helps to control the number of slugs in the area. To prepare it, add 10 g of grated laundry soap and 20 tbsp to 3 liters of water. l. soda ash. Stir the solution before use. Carry out the processing of cabbage in the morning every five days, if the holes appear in a small amount.
- Sagebrush. This remedy is effective against scoop and white caterpillars, as well as aphids. To prepare it, you need to grind 0,5 kg of leaves and shoots of the plant and pour 5 liters of water. Boil the mixture for half an hour after boiling, and then insist for a day. After the waiting period, dilute the concentrate with water in equal proportions. Before spraying cabbage, pour 100 ml of liquid soap into it. Apply when holes appear on the leaves every five days.
- Ammonium chloride. This component repels a fly, butterflies, flea, aphids. For processing, you need to dilute the bottle of the drug in 10 liters of water. Spray the plantings of cabbage with the resulting solution, on which holes have appeared, and moisten the ground at the base of the seedlings. Repeat the procedure every three days.
Mechanical methods
At the initial stage of damage to cabbage by pests, manual collection of insects can be carried out. However, this may only temporarily slow down their spread, but will not solve the problem.
You can also use agrofiber to protect cabbage plantings from butterflies and flies. To do this, it is recommended to cover the plantings during their active summer. And against slugs and snails, it is recommended to place special traps with syrup or beer in the garden, two for each square. m. Every day they need to be inspected and destroyed by the pests gathered inside.
Agrotechnical control measures
When holes appeared on cabbage leaves, it is necessary to apply agrotechnical methods of control. To do this, it is necessary to regularly weed the vegetable plantings, to prevent weeds from flowering, which attracts the attention of butterflies.
Insekticidы
If cabbage leaves are in holes, it is recommended to treat the culture with special chemicals – insecticides. They are fast acting. After spraying, pests lose their ability to move and eat, and eventually die. The treatment must be carried out twice, since insecticides have a toxic effect on adults and pest larvae, but they do not penetrate the egg shell.
The most effective of them, if holes appeared on the cabbage leaves:
- Aktara.
- Karate Zeon.
- Fufanon.
- Diazinon.
- Confidor Extra.
Chemicals must not be used during crop maturation
Other chemicals based on metaldehyde are suitable against slugs. They are sold in the form of granules, which must be scattered on the surface of the soil in places where they accumulate and move. This leads to the death of the slugs.
Methods of prevention
To prevent holes from appearing on cabbage leaves, you need to follow simple rules of prevention. They cannot completely eliminate cruciferous crop damage by pests, but they reduce this probability to a minimum.
Basic preventive measures:
- observance of crop rotation;
- deep plowing in autumn;
- timely removal of plant residues from the garden and burning them;
- early planting of seedlings before the mass reproduction of insects.
Conclusion
Holes on cabbage can appear at any time during the growing season of the crop. Therefore, throughout the season, you need to regularly inspect the plants and respond in a timely manner to alarming signs, without waiting for the mass reproduction of pests. This will help minimize the damage that insects can cause to the crop.
