Yellowed and sluggish carrot tops are an alarming sign that should attract your attention. Yellow leaves in carrots indicate both improper care and the presence of a disease or pest exposure.
Wrong variety selection
Use for growing those varieties of carrots that are zoned in your region, increases the resistance of plants to adverse environmental conditions, various types of diseases.
Depending on the ripening period, there are three main groups of varieties:
- early ripening or early ripening (85-100 days from germination);
- mid-season (95-120 days);
- late ripening (more than 125 days).
For the northern regions of Russia, early-ripening varieties with a ripening period of about 90 days and excellent keeping quality are recommended.
In the southern regions, during the season, you can get harvests from both early maturing and mid-maturing, late-maturing varieties.
Non-compliance with the watering regime
Carrots are very demanding on the amount of moisture received during the growing season:
- With a lack of water the growth of root crops slows down, the plants become weak, and the tops can become lethargic or even dry.
- Too abundant watering promote the growth of pathogenic bacteria and the appearance of fungal infections. They cause yellowing of the tops. When watering with a strong stream of water, the aerial part of the root crop is easily injured, it can dry out later.
It is best to work out a watering schedule and adhere to it; watering carrots with a frequency of 1 time in 4-5 days is most effective.
Ideally, the carrot beds should be soaked to the depth of the middle of the underground part of the plants. On the hottest days, in the absence of natural precipitation, watering is carried out 3-4 times a week.
Shortage and oversupply
Carrots need a lot of nutrients. The main components (nitrogen, phosphorus, potassium, boron, manganese) plants should receive throughout the maturation.
The lack of certain microelements causes changes in the tops:
- potassium - yellow veins on the leaves with signs of withering away along the edges, wilting;
- nitrogen - pale color, slow growth;
- manganese - yellow-whitish spots, necrosis.
The imbalance of phosphorus and boron does not cause yellowing, but also badly affect the condition of root crops.
With an excessive content of nutrients in top dressing, branching is observed in root crops, when the root is divided into two or three trunks, there is an excessive accumulation of nitrates. The tops may turn yellow when using too much fresh manure.
How to correct the lack of substances:
- Potassium. To quickly correct a potassium deficiency, fertilizing with potassium sulfate is carried out, at the rate of 20 g per 1 square meter. Potassium sulfate can be applied both in dry form and in dissolved form, combining with watering.
- Nitrogen. To eliminate the lack of nitrogen, it is introduced into the soil in the form of potassium, sodium nitrate, ammonia, organic and other fertilizers (see dosage on the package).
- Manganese. To solve the problem, spray the tops with Aminofol Mn, AM EDTA Mn 13% (Chelate Mn), manganese sulfate (see dosage on the package).
To eliminate the overabundance of nutrients, keep the plants in clean water for a couple of days and then gradually restore nutrition (fertilizers), first entering 50% of the dosage and gradually increasing it to 100%.
If you use complex fertilizers, but the problem repeats itself, most likely the reason is not fertilization, but external factors.
Hot summers or frosts
At high air temperatures, the assimilation of nutrients from the soil worsens, the amount of chlorophyll in the leaves decreases, and the process of photosynthesis is inhibited. Outwardly, this manifests itself as yellowing and drying of the tops.
How to save the carrot crop in the heat:
- Water the plants as often as possible. Better to do this early in the morning so that the moisture has time to be absorbed before the sun and wind evaporate it.
- Pour water only at the root, being careful not to wet the tops - it may cause a sunburn.
- Rare abundant rare watering is better than scanty and frequent. Plants only suffer from surface watering in the heat.
- Loosen the soil regularly after wateringavoiding crust formation. During prolonged heat, you should loosen the soil around the carrots before watering, make a small hole so that the plant is in the middle of the depression.
- Stop weeding temporarily, the weeds will give the carrots a small shadow and thereby save it from the scorching rays of the sun. Of course, they "steal" part of the water for themselves, but they will bring more benefits.
Carrots are cold-resistant plants that can withstand temperatures up to -5 ... -7 ° C, so she experiences spring frosts calmly.
Diseases and ways to deal with them
Diseases of carrots, manifested by yellowing of the leaves:
- Jaundice. Refers to viral diseases. The causative agent of Phytoplasma is carried by aphids and small insects. Leaf veins become dark, shoots grow on the roots, leaves turn yellow.
The main methods of control are preventive:- crop rotation compliance;
- seed treatment with a solution of polycarbacin (5 g of the drug per 1 kg of seeds);
- keeping seeds in hot water with a temperature of 50 ° C for 30 minutes.
- White and brown spotting. Alternaria fungal disease (causative agent of Alternaria dauchi). Pinpoint lesions of leaves and petioles appear with brown spots. In the future, spots of rot appear on root crops.
The yield is reduced by up to 50%, the weakest plants can turn yellow and dry out. Elimination methods - preventive temperature exposure of seeds, crop rotation. Treatment with Bravo or Quadris preparations is carried out twice with an interval of 10 days. - Fomoz. The causative agent is the fungal cultures Phoma rastupii or Leptosphaeria libanotis. Affects testes and root crops, causes rot during storage. Petioles and leaves are affected by long brown spots with sticky secretions, branches are lilac.
Without treatment, the tops turn yellow and dry. Cavities with a moldy surface are formed in root crops.
Eliminated by:- processing of seeds and fruits with Fitosporin-M;
- the introduction of increased doses of potash and phosphorus fertilizers;
- observance of crop rotation;
- sorting fruits before laying them for winter storage;
- separate storage of testes and fruits.
- Bacteriosis.Wet bacterial rot. The causative agents are Pseudomonas and Bacillus. The defeat begins with yellowing of the lower leaves, then the spots darken, go on to the root crop, causing the appearance of pressed wet spots with an unpleasant odor.
To get rid of the disease, observe crop rotation, do not allow too much watering, treat the affected beds with Hom. - Cercosporosis.Caused by the fungus Cercospora carotae. Small brown spots with a light middle appear on the leaves in mid-summer. Gradually they grow, connect with each other. A thick gray coating appears on the back of the leaves.
The spots look depressed on the outside. The leaves turn yellow and die off, the root crop does not receive sufficient nutrition and grows small and wrinkled.
Eliminated by:- removal of plant debris from the soil;
- deep digging of the site;
- the use of disease-resistant varieties;
- processing of plantings with preparations "Bravo", "Quadris", "Baikal-M", "Fitosporin", "Trichodermin" and others;
- cleaning carrot storage rooms with sulfur drafts, whitewash, lime with the addition of copper sulfate.
- Rhizoctonia (felt disease). Caused by the pathogenic fungus Rhizoctonia violaceae Tul. Subcutaneous gray spots appear on the roots. In the future, the spots grow, cover the entire surface of the root, acquire a purple tint. The leaves turn yellow and dry out.
The disease often manifests itself during winter storage. Root crops become brown, gradually soften, the skin is most severely affected.
Elimination of pathogens:- disinfection of soil under infected areas after harvesting;
- no planting of carrots in the infected area for at least 4 years;
- adding lime to the soil;
- increased application of phosphorus and potash fertilizers;
- timely elimination of weeds, which can also be affected by rhizoctonia.
Pests and ways to combat them
In addition to bacterial and fungal infections, carrots can also suffer from insect pests.
Carrot flies
The appearance of this pest becomes noticeable by the twisted leaves that look like parsley.
In the summer, the carrot lice gives one generation, hibernates in the bark of coniferous trees or in the remains of wild carrots. In the spring, lays eggs on carrot seedlings. The larvae that emerged from the eggs and the fleas themselves feed on the sap of the leaves. Seedlings lose juices, turn yellow and die.
Prevention of the appearance consists in:
- destruction of wild carrots on the site;
- fencing carrot beds from coniferous plantings;
- processing plants with daily tobacco infusion, prepared at the rate of 30 g of laundry soap, 1000 g of dry raw tobacco per bucket of boiling water;
- use for spraying crops with preparations "Arrivo", "Actellik", "Decis", "Sumicidin".
Gall nematodes
Round worm of white color, length 1.2-1.5 mm. Causes meloidoginosis. The root crop curls up, does not grow, several processes of an ugly shape are formed. Becomes noticeable by yellowing and wilting of leaves.
To get rid of nematodes:
- plant marigolds, calendula, mustard in the aisles (this is also suitable as a prophylaxis);
- use chemical preparations-nematicides "Tiazon", "Heterophos" and others.
Carrot fly
The larvae of this pest feed on root crops. The leaves of infected plants turn purple, then turn yellow and dry out. Rot appears in the passages gnawed by larvae, because of this, the whole fruit also rot.
To get rid of and prevent the occurrence of this pest, use:
- sowing seeds of varieties resistant to carrot flies;
- treatment of the site with insecticides azofit, trichodermin, Inta-Vir, Arrivo, Aktofit;
- pollination of plants with ash mixed with ground pepper and mustard powder;
- spraying with infusions of marigold flowers, wormwood.
What if all else fails?
If none of the above methods of combating yellowing of carrot leaves gave a good result, select several affected plants and contact the nearest plant protection station.
Before finding out the exact cause of the infection, refuse to plant carrots in this place, and possibly other root crops, for several years. Plant green plants on the land to repel pests and improve the soil.
Prevention
Of the preventive measures, the main ones can be distinguished:
- Compliance with crop rotation.Plant carrots in areas after plants that are not affected by carrot diseases and pests. These are solanaceous (potatoes, peppers, eggplant), cabbage and cruciferous, cucumber, zucchini, pumpkin, squash, spicy plants and herbs.
- Timely removal of affected leaves. Remove all plant debris in and on the ground. This measure will not allow pests to survive the winter and multiply in large numbers.
- Tillage.To get rid of pathogenic bacteria, fungi, spray the soil or water with solutions of fungicides and insecticides.
- Use of reliable varieties.Plants that are resistant to disease will yield good yields and save you the trouble of using plant protection products.
- Proper care Watch for timely, but not excessive watering. Bacteria and fungi thrive best in a humid and warm environment. Combine watering and treatment of plants with drugs.
Apply fertilizers at rates that correspond to the development of carrots, use complex fertilizers in accordance with the recommended amounts and on time.
If there is a risk of infection, use manure with caution, because it can become a source of pathogens. Weeding, thinning plants, loosening row spacings will strengthen the plants and prevent pests from multiplying.
Timely detection of yellowed leaves will give you the opportunity to take control of the problem on the bed in time and eliminate it. To prevent yellowing and drying of the leaves, use prevention methods, water and fertilize the soil on time, carry out weeding and loosening.
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Russia. City Novosibirsk
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