Photos and descriptions of dill diseases and the fight against them
Despite the unpretentiousness of dill, it is not always possible to get the desired greens. And this is due to diseases affecting plants, the causative agents of most of which are harmful fungi.
According to the results of long-term observations carried out by specialists of seed-growing and selection farms, powdery mildew, phomosis and cercosporosis are the most dangerous for dill crops. However, this is not a complete list of dill diseases. What to do if dill turns yellow in the garden, or its greens turn black and curl? Descriptions of diseases and photos of affected plants will help to recognize a disease of a garden crop and determine control measures.
Read also the article: onions turn yellow - what to do?
Powdery mildew of dill
In protected ground, the pathogen of powdery mildew is found in greenhouses where weeds are present, and in open beds, powdery mildew often infects crops in warm, humid weather.
A characteristic feature of the disease is a whitish, first like a cobweb, and then traces of whitewash or flour, a plaque consisting of the mycelium of a pest fungus. The spots appearing on the greenery capture all new surfaces until the disease affects all the aboveground organs of the plant. Foliage that has traces of powdery mildew loses its juiciness, aroma and taste.
Like most pathogens of this type, the spores of the fungus overwinter in plant debris that have not been removed from the beds, and also persist on weeds. Wild species of Umbelliferae are especially willing to inhabit spores.
Peronosporosis dill
Downy mildew or downy mildew, similar in appearance, also affects the aerial part of the plant. The greatest bursts of infection are observed in wet weather, at temperatures from 18 to 20 ° C.
As the infection develops on the outside, the foliage of the dill turns yellow and becomes brown. A thick white bloom is clearly visible on the back. A similar picture develops on umbrellas, seeds and shoots. Over time, the plant affected by peronosporosis practically dries up.
What to do when dill turns yellow in the garden? The source of the disease lies in the fallen and not harvested parts of plants, weedsand the disease can also spread through already infected seeds. Therefore, in no case should weed vegetation and particles of infected tops be allowed on the soil.
Fomoz of dill
The reason why dill turns black in the beds may lie in the tissues of plants affected by the pathogen of phomosis. The disease, widespread from the Non-Black Earth Region to the Krasnodar Territory and the Volga Region, causes serious damage to both large agricultural plantations and amateur plantings in personal plots.
Manifestations of the disease can be seen on young seedlings along with a black leg affecting the stems, or in the second half of summer on adult dill bushes.
The harmful fungus Phoma anethi Sacc permeates all plant tissues, which outwardly manifests itself in the appearance on the stems, leaves, inflorescences and even on the roots of dark elongated spots with noticeable black dots.It is the vital activity of this mushroom that can be the answer to the question of why dill turns black in the beds. Since the development of the fungus on the affected dill plant lasts no more than 2 weeks, the pest gives many generations per season and can cause several waves of the disease. Spores spread with wind, rain and insects, and remain in dead parts of plants trapped in the soil, seeds and weeds.
When dill is infected with phomosis at the stage of seed formation and maturation, the latter lose their germination and become sources of infection.
Cercosporosis of dill
Cercosporosis has a lot in common with fomosis of dill and, in fact, precedes the development of this disease. This is noticeable in the photo of dill, and disease control also includes general measures. Why does dill turn black in the beds? All aerial organs of dill suffer from the infection spread by the fungi Cercospora anethi, on which dark or brown spots appear at the sites of the fungus, which eventually take on an elongated shape and shape along the vessels.
When the spores begin to ripen, the spots become covered with a dense, lighter bloom. The source of infection remains on ripe seeds, as well as on dry residues not harvested from the beds.
Black leg of dill
Losses of dill seedlings from black leg most often occur in greenhouses or when growing crops in greenhouses on a personal plot.
Seeds infected with a fungal infection become the source of the disease. As a result of their activation, rotting of the root collar begins, as a result of which the dill turns black, the plant stems weaken and dry out in the first days after the emergence of seedlings. The development of the black leg goes right up to the beginning of the opening of the true leaves. And in conditions of high humidity, up to 50% of the crops lodges and perishes.
The development of the black leg is facilitated not only by excessive watering, but also by:
- sharp temperature fluctuations;
- lack of ventilation in the greenhouse;
- multiple use of the same soil in greenhouses and greenhouses, as well as when growing seedlings;
- lack of loosening and the resulting crust on the soil surface;
- increased acidity of the soil;
- low illumination;
- insufficient thinning of crops.
That is why dill seedlings turn black on the beds.
The risk of spreading the black leg increases many times if untested seeds are used during sowing, possibly infected with phomosis and cercospora.
Fusarium wilting of dill plants
Fusarium on dill begins with the lower leaves, first the dill greens turn yellow, then the color changes to reddish or brown. As the disease spreads, it spreads to the upper tiers, and the plants gradually wither. The degree of infection can be judged by the cross section of the stem, the vessels of which can also acquire a yellowish, brown or red color. If the dill in the garden turns yellow, what should the gardener do?
The pathogens Fusarium fungi accumulate and overwinter in the soil. Therefore, soil pests can be a carrier. The fungus can get into the tissues of dill with careless loosening, as well as with nematodes. A risk factor for the development of fusarium is regular waterlogging of the soil, as well as an increased soil temperature.
It is highly undesirable to allow stagnation of moisture in the soil and the reproduction of soil pests.
Verticillary wilting
The fungus, the causative agent of this disease, affects the vessels of the plant. As a result of the development of infection, withering dill bushes completely lose their ability to receive food and moisture, and the vascular system becomes clogged. The first signs of the disease can be seen in mid-June, and the complete picture develops already in the second half of summer, when the dill blooms and forms seeds. At first, infected dill turns yellow only in hot weather, then the foliage completely withers, curls and turns brown.
Sources of a disease dangerous for dill are soil infected with the fungus Verticillium dahliae, poorly rotted manure or compost.
Dill disease control measures
Since green crops, including dill, are extremely early ripening, toxic chemicals cannot be used to combat disease-causing fungi and pests.
And as you can see in the photo of dill diseases, the fight against them cannot be limited to one-time treatments. Therefore, the main attention must be paid to the prevention and prevention of the development of infections dangerous for crops.
To prevent the spread of disease through seeds and prevent fungi from killing seedlings, it is extremely important to choose only proven healthy seeds, and also to decontaminate the seeds before planting. This can be done by soaking the seed in water with a temperature not exceeding 45 ° C for 20-30 minutes. At the same time, the fungus dies, but the embryo does not suffer, which allows you to get healthy plants and a bountiful harvest of fresh herbs.
For sowing, it is necessary to allocate well-lit, ventilated areas with light, loose soil. Soils with an acidic reaction are subjected to liming. Dill should not be sown in the same place for many years. It is better to alternate the crops of this culture with legumes, nightshades, melons. Since umbrella crops are often affected by some diseases and pests, it is not worthwhile to coexist with carrot, dill or celery beds.
Excessive crop density should not be allowed, which contributes to both the weakening of plants and the development of all kinds of infections.
Soil and flying pests can successfully spread fungal infections. The reason why the dill leaves curl may be a colony of aphids that have settled on the plants. But if the insects can be washed off with water, then the fungi that enter the tissue as a result of punctures cause irreparable consequences. And here it is vital to take all measures to protect dill not only from aphids, but also nematodes, wireworms, carrot moths and miner flies.
You can secure planting by regularly removing all weeds, both on the beds themselves and along their perimeter. During weeding and after harvesting, plant residues that store pathogens must be destroyed.
What to do if dill turns yellow, turns red or leaves of the plant curl in the beds?
To protect dill from fungal infections and other diseases, regular feeding of umbrella crops with phosphorus and potassium fertilizers will help. If compost or manure is used for fertilization, in which fungal spores are perfectly preserved, it is better to replace them with factory-made dressings. Foliar dressing of dill and other green plants with a weak borax solution is a good remedy.