Gardeners who do not observe caution and do not conduct disease prevention receive diseased plants, low productivity and contaminated soil. If you spray the seedlings, flowers, shrubs and trees once every 2-3 weeks, then this will protect the site from big trouble - diseases and pests.
Diseases and pests of irises and their treatment is also a matter of correctly carried out prevention or its absence.
Bacteriosis
Despite their relative resistance to diseases, iris flowers, diseases and pests of which are very dangerous due to the peculiarity of plant propagation, can still become infected. The most serious and dangerous disease for these flowers is bacteriosis.
It is caused by the Erwinia carotovora bacteria, which, settling in moist and nutrient-rich rhizomes, cause their decay.
Too frequent soil moisture, oversaturation with organic matter, thickened planting, many old flowers endanger irises. Pests and diseases manifest themselves when the owner of the site forgets the simple rules for caring for these flowers - watering as necessary, thinning and moderate use of organic substances.
Signs of bacteriosis:
- rhizomes become soft;
- the roots turn into a "mess" with an unpleasant odor;
- "Fan" of foliage falls.
Unfortunately, badly damaged irises, pests and diseases that caused irreparable damage, are not subject to treatment. This is also true in the case of bacteriosis, which spreads very quickly at temperatures from +13 to +17 degrees. Plants should be separated from still healthy rhizomes and burned.
It is important to remember that sick irises should never be used for compost, and in case of severe soil damage healthy flowers are recommended to be transplanted to a new place.
Treatment, prevention of bacteriosis
Once the snow has melted, check out the irises. Protection from pests and diseases begins with ensuring the outflow of melt water if there is no natural slope in the flower bed. In winter, as a disease prevention, wrapping the roots of irises from freezing is used. Rhizomes damaged by frost are the first to be at risk of disease, therefore, they must be destroyed.
In the event that bacteriosis has not completely damaged the root, only areas affected by bacteria are cut out, and the sections are smeared with brilliant green or ash is rubbed into them. This work is carried out before flowering.
Also, for preventive purposes, foliage should be sprayed with a solution of urea mixed with 12% sulfur. During the transplantation of young rhizomes, it is recommended to hold them in a solution of potassium permanganate for 15-20 minutes for disinfection.
Wet rot
Diseases and pests of irises and the fight against them are quite complex issues. They concern not only rhizomes, but also leaves. The presence of a disease such as wet rot can be noticed when the leaves of the plant begin to turn brown and dry. In this case, the roots of the iris become powdery from the inside, which is not noticeable from the outside.
Wet rot affects flowers and slows down the development of not only irises, but also gladioli, tulips and hyacinths. This bacterium appears in the soil from manure, which fertilize it. To prevent infection, before planting irises (pests and diseases then bypass them) are treated in a solution of potassium permanganate for 30 minutes. It is enough to put half a teaspoon of the substance in 0.5 l of water, lower the rhizome and pickle it.
Fusarium
Gray rot (fusarium) is also dangerous for iris, from which both the roots and foliage of the plant suffer. At the same time, a gray coating appears on the leaves, which leads to their decay and death. The roots are affected by dry rot, which appears due to the high nitrogen content, therefore, when feeding the soil with mineral fertilizers, the dosage should be strictly adhered to.
The right place to plant will be a good prevention of the disease. And pests of irises, and their treatment will not become irreparable damage to the entire flowerbed, if you plant flowers either on a natural elevation, or on a raised raised bed.
A plot of soil contaminated with fungus can become the culprit of infection of all the land near the house if you cut and transplant already diseased iris tubers. The fungus remains in the soil and when favorable conditions (high humidity, temperature + 12-17 degrees) appear, it will damage the surrounding plants.
The first sign of the disease is the appearance of a gray spot on the rhizome. The flesh beneath it becomes brown and friable, and inside the root blackens. For safety, irises (pests and diseases then recede) must be treated with copper sulfate or bicarbonate soda of 5% strength before planting.
Another simple way of prevention is to process garden tools before work.
Heterosporosis
This is a fungal disease of the leaves. It is caused by the fungi Heterosporium iridis and Mycosphaerella macrospora. Diseases and pests of bearded irises of this type are manifested primarily on old and tall leaves.
Gray-white spots with a yellow border appear on them, which, as the fungus grows, capture an increasingly large surface of the leaves until they cover the entire bush.
For prevention, irises should be sprayed with fungicides and not oversaturated with phosphorus and potassium. From the onset of the disease, it is recommended to pick off and burn diseased leaves, and spraying once a week and after rain.
Botritis and rust
Irises are often affected by fungal diseases. For example, two fungi cause Botritis at once - Botrytis convoluta and Sclerotium rolfsii. They can develop with improper storage of rhizomes in conditions of high humidity and poor ventilation.
If such planting material is planted, then when it rains, the fungi begin to multiply intensively, destroying the plant completely and affecting neighboring crops.
For prophylaxis, dividers should be stored in the correct conditions and treated with a solution of triazole class fungicides.
Sheet mosaic
Diseases and pests of irises and their treatment are not limited solely to fungal diseases. Plants are also susceptible to viruses. Well-known to flower growers is a mosaic of leaves, in which they become yellow-green and dry quickly.
Damaged foliage must be immediately torn off and burned, and the bush itself should be sprayed with a 0.2% solution of copper chloride and Ridomil Gold.
In order to notice the disease of flowers in time, you should carefully look at the color of their flowers. If they become spotty or as if melted, and light flowers become dirty and dull, then the plant is infected with a virus.
For prevention, it is necessary to decontaminate equipment every time before gardening, spray the area with fungicides and clean it of weeds.
Thrips, Nematodes and Bronze Beetle
Many irises, diseases and pests (confirmation of which photo) are most often affected by the roots, suffer from small insects - thrips, which settle in the axils of the leaves. They feed on the plant cell sap, causing their deformation. Most of all thrips love Siberian and Japanese varieties of irises, but do not disdain the "bearded" species.
As these sucking insects “conquer” the plant, its leaves turn brown and dry, and the roots become covered with brown spots.
From thrips can be saved by spraying karbofos emulsion (10%) based on 10 l of water 75-90 g of the emulsion. Spraying should be done once a week.
Nematodes are small translucent worms that are not afraid of frost. They settle in the base and buds of plants and are activated with the onset of heat. With their "stylet" proboscis, they pierce the epidermis of the leaf and feed on its cellular juice. At the puncture site, the leaf turns brown and dies.
Nematodes are often transmitted by garden tools, with weeds and rainwater. Systematic weeding of weeds with inventory processed in a 10% formalin solution and steaming the soil before planting will help to avoid infection.
Large green bugs reaching a length of 2 cm are popularly called bronzes. They are activated from the end of May and fly in the gardens in search of pollen, not disdaining the delicate flowers of irises as well. Diseases and pests of irises and their treatment are what the grower needs to have special knowledge about. With the invasion of bronzes, flower treatment begins with spraying the plants with Kinmixom at the rate of 2.5 g per 1 liter of water.
If there are not very many beetles, they can be collected manually, and for prevention, spray flowers with ash solution.
Aphids and slugs
During the blooming period, many insects are activated, which do not bypass irises. Pests and diseases during flowering plants destroy not only roots and leaves, but also flowers. For example, aphids accumulate in buds and “suck” life from plants, feeding on their juices.
Since aphids multiply rapidly, the plant can die completely in a short time. To avoid this, spray the damaged flowers with 0.3% karbofos emulsion or 15% phosphamide.
If there are no chemicals at hand, then a solution of soda ash (0.5%) with the addition of soap is suitable. Another way to protect plants from aphids is to regularly weed.
Slugs live in the lower tier of leaves and in the upper layers of the soil. During the day, they hide, crawling out for feeding at night. They eat leaves, and in the rhizomes eat whole cavities. Intensively breed in rainy periods at a temperature of + 18-20 degrees.
In the form of prevention, a deep digging of the earth and the destruction of last year's leaves can be carried out. You can get rid of slugs by a folk remedy - to spray flowers and closely growing trees with a decoction of bitter pepper.
The land is cultivated with ash or a mixture of lime and tobacco dust. Also, many gardeners set traps for slugs - bowls of water dug into the ground. When they get into the dishes to get drunk, they can no longer get out of there. It remains to destroy them and pour fresh water.
Scoops and Bears
Caterpillars of the butterfly scoop destroy irises from the inside, gnawing whole labyrinths in the stem of the plant. Most of all, they like moist areas, so draining the soil is a preventive measure. It is also recommended to loosen the soil in the row-spacing and destroy weeds, especially during the laying of eggs.
Bordeaux liquid, which is made from a mixture of copper sulfate and milk of lime, has a good effect on diseases and pests of irises. It should be used before blooming.
If the moment was missed and caterpillars appeared, it is recommended to spray them with a decoction of Lobel’s hellebore.
Bears have powerful jaws with which they gnaw roots and stems. Irises (diseases and pests, photos confirm this, in most cases are less dangerous than this insect) die if a bear colony settles under them.
You can destroy them using bait. To do this, cook 1 kg of grain, add 30 g of oil and 50 g of malathion to it and mix well. It is enough to dig this mixture 5 cm into the ground or push it into their burrows.
Wireworms
The wireworms are called the larvae of the nutcracker beetle, which live in the root zone of the flowers. Irises, diseases and pests, the treatment and prevention of which often depend on the quality of digging and loosening the soil, can avoid many problems with "health" if the gardener makes enough effort. To get rid of wireworms, it is recommended to add anhydrous ammonia to the soil and regularly destroy weeds.