The main diseases and pests of irises, how to get rid of them. Iris root rot

Irises are beautiful flowers that delight the eye of flower growers in early summer. However, these perennials may be susceptible to a number of infectious and viral diseases.

And if you know why the foliage of the plant turns yellow and dries out ahead of schedule, the buds fall, the flower stalks dry, then you can begin to effectively fight the disease, as well as save the flower garden from infection.

It is worthwhile to figure out which main diseases of irises are most common and what kind of treatment is needed.

There are not so many major diseases of these types. But you should get to know them in more detail.

Mosaic

The main symptoms of the mosaic are the appearance of light spots and medium-sized stripes on the foliage, this disease is caused by a virus. This pathogen is usually carried by aphids.

Plants affected by it slow down their growth, their peduncle is much smaller than that of other irises, and the flower petals are too variegated with a lot of stains, and the color of the buds is darker than their usual color.

At present, drugs to combat mosaic have not yet been invented, so diseased plants are removed and burned.

Irises should also be watered regularly, a sufficient amount of fertilizer should be applied to the soil, and the flowers should be sprayed against pests. various drugs(such as "Golden Iskra", "Atellica", "Furranon", etc.).

soft bacterial rot

This disease appears on flowers already at the beginning spring period. Its first symptoms appear on overwintered leaves - brown spots are immediately noticeable to the experienced grower.

Such plants grow during the season with these lesions, and then the rot spreads to the base of the flower.

This disease can also affect the roots of the flower, in which case the rhizomes soften and acquire an unpleasant "aroma".

The causative agents of this disease can long time persist in plants as well as in the soil, so all diseased parts of plants should be collected and burned. And the soil is usually watered with an antibacterial solution (Tiazon pesticide or similar preparations).

As soon as the first symptoms of bacterial rot appear, the diseased parts of the plant are immediately removed to a healthy place, and the sections must be cauterized with a solution of potassium permanganate or charcoal. And in the future, for breeding irises, only healthy plants should be taken for planting in open ground.

Fungal diseases of flowers

Diseases caused by fungi can also damage irises. And sometimes it is not easier to deal with them than with other types of diseases. The main ones are discussed below.

Alternariosis

With this disease, the first symptom is a blackening of the edge of the foliage with the formation of a dark coating. In the future, this foliage dries up and disappears.

The affected foliage should be immediately removed and burned, otherwise the fungus will enter the soil and remain there until next year(his controversy). Therefore, the soil where diseased flowers grew should be sprayed blue vitriol or Bordeaux liquid.

Rust

The main symptoms of the disease are the appearance of pustules at the ends of the foliage. Brown color, which further lead to yellowness and drying of the leaves.

In autumn, a plaque appears on diseased plants, where the spores of the fungus are located. They are able to withstand even a strong cold snap, and with the advent of heat they are transferred to healthy plants.

For preventive purposes, it is necessary to arrange good drainage in flower beds, destroy diseased foliage.

Healthy foliage should be treated with products containing sulfur (garden sulfur, Thiovit, etc.). spray the flowers once every 14 days until all symptoms of the disease disappear.

Ascochitosis

Dark spots, the edges of which are watery, are the first symptoms of ascochitosis. In the future, damaged leaves dry out ahead of schedule.

The fungi that cause this disease can overwinter in the soil, therefore, as a preventive measure, flowers should be sprayed before buds appear and after flowering with preparations containing Cu.

heterosporiosis

Round or oval spots on leaves yellow color- the main symptoms of this fungal disease. Subsequently, these tan marks become brown with a gray tint. Then the spots begin to grow, a plaque of spores appears on the surface of the leaves.

Usually effective tool The fight against this disease is the spraying of flowers with preparations containing copper. All diseased parts of irises are collected and destroyed.

Gray rot

For this disease characteristic yellowing of the leaves almost immediately after the last flower dries. In this case, several fungi infect irises at once. One penetrates the soil and infects the roots with dry rot. As a result, rounded seals appear on the roots.

Another fungus appears during humid and warm weather. At the same time, brown spots and plaque appear on the foliage and buds. gray shade. Appearing spots of yellow color are a symptom of the formation of spores that “hide” in the soil for the winter.

To avoid this disease of irises, you should choose only healthy specimens for planting, seat them in well-drained soil, and also destroy diseased plants in a timely manner.

Previously, irises were thought to be fairly trouble-free flowers to grow. But breeders in their science do not stand still and deduce every year all large quantity irises. The more refined and beautiful the flower looks, the more attention it requires when leaving. Therefore, there is a risk of various diseases. Let us consider in more detail what viruses and diseases irises are exposed to, what control measures are appropriate and how to keep your flower garden intact. And photos and videos will help us to present information more fully.

Bacteriosis (bacterial rot)

This rot is the most dangerous for irises. The development of the disease is facilitated by a high nitrogen content in the soil, dampness and thickened planting. Rot begins at the base of 1-2 leaves. The damaged area becomes soft, the leaves dry and turn yellow. The disease spreads rapidly bad smell. Preventive measures:

plant irises in drained areas;
avoid mechanical damage to rhizomes;
always destroy pests;
in spring and August, it is necessary to rake off the mulch - this will not allow the root neck to warm up.

bacterial rot

Bacteriosis control:

destruction of diseased specimens;
crushed can be used for processing Activated carbon, a suspension of captan and a 0.5% solution of potassium permangatanate;
suspicious areas should be powdered with doxycycline, penicillin, or lincomycin.

Fusarium (dry rot)

A disease of the fungal group that damages the vascular system of flowers. It occurs during prolonged wet weather, when the temperature range is wide enough (from +2 to +32 degrees). Rot looks like gray-brown spots, slightly depressed. There is no smell. The tissue affected by the disease becomes almost black and loose. The rhizomes are completely dry. For prevention, it is necessary to strictly observe agricultural technology, strictly follow the recommendations for fertilizer, and not damage the plants. To overcome rot, it is necessary to completely remove all infected specimens, and pour the soil with copper chloride. Intact irises should be treated with fungicides.

Advice! In the area where there was dry rot, irises should not be planted for 4 years!

Gray rot

Another fungal disease to which irises are exposed. With it, the petals of the flower begin to turn brown, then dry out and become covered gray coating. This plaque is formed by fungal spores. Merging spots of a rounded shape begin to appear on the tips of the leaves. The areas between the spots dry up and turn yellow, gray sporulation actively develops on them. Later, black sclerotia appear inside them.

With gray rot, the leaves of irises are covered with bloom

Important! Gray mold infection persists in all flower residues. Therefore, during the autumn harvest it is very important to burn everything that is left after the irises.

You can fight rot by the following measures:

for planting, use only healthy specimens of flowers, carefully monitor that they do not show signs of infection;
irises should be grown only on drained soils, strictly follow the rules of agricultural technology;
monitor plants during the growing season - urgently remove seen affected leaves and flowers;
in the fall, be sure to collect all the remnants and burn them.

Rust

It appears on the leaves as numerous brown pustules. Then the leaves turn yellow and dry. In September, a velvety coating forms on the affected leaves - this is how the mushrooms pass into the wintering stage. After overwintering, fungal spores infect valerian. In spring, spores on valerian begin to develop actively and attack irises. You can fight rust in the following ways:

do not plant irises next to valerian or keep a sufficient gap between these plants;
choose only drained areas for flowers;
treat affected specimens with sulfur preparations - Thiovit, Garden sulfur, Colloidal sulfur; the treatment interval is 14 days until the disease disappears.

Rust

Mosaic

Usually aphids bring mosaic to irises. The disease begins its manifestation in the form of small light stripes and spots that appear on the leaves of the flower. Diseased specimens begin to lag behind in their development. Their peduncles are shortened, and the petals are spotted.

Advice! Timely detection of the disease will help regular thorough inspection of plants. If spotting or melting of flowers was noticed, they are more light shade, then this indicates the presence of a mosaic.

Not found yet effective measures fight against an already developing disease. Therefore, all efforts must be directed to prevention:

High-quality level of agricultural technology.
Timely watering.
Appropriate feeding.
Fight against aphids with the help of drugs - Iskra Zolota, Inta-Vir, Arrivo, Aktara, Aktellik, etc.
If a mosaic is found, affected specimens should be removed immediately;
The remaining healthy flowers must be sprayed with a 0.2% solution of copper oxychloride.

Aphids infect irises with mosaic

Despite the excellent resistance of irises to diseases, there is still a risk of their occurrence. And it is connected, first of all, with improper agricultural technology and the lack of preventive measures. As practice shows, strict adherence to the rules of planting and care, disinfection of tools, burning of plant residues and the correct regime of watering and fertilizing will help to avoid attacks of diseases.

Diseases of irises - video

The genus of irises includes about 800 species, which makes them the subject of unique collections. If you look at the photo of plants, you can not help but notice some resemblance to orchid flowers. Selection of iris is very fast, new varieties of unusual colors are often unstable to diseases. In addition to bacteria and fungi, some insects are affected. For pest control, there are many available funds. You can learn more about them from the thematic videos or articles.

Bacteriosis - wet root rot

Pathogens - bacteria groups Erwinia aroidea, Pseudomonas iridis. The disease affects the base of the leaf and the root collar of the plant.

Causing disease:

excess moisture;
thickening of crops;
stem freezing.

Bacteriosis of irises

Initially, the focus is small, inconspicuous. Infected leaves dry up. The disease goes to the middle of the root. Prevention:

placement of landings on well-drained soils;
avoid damage to plant parts, rhizomes;
pest control.

Advice! Iris plants planted on a slope will be the least susceptible to fungal infections.

Of the drugs that can cure an infected plant, botanists recommend doxycycline powder. It is also used to combat rot in orchids. Suspicious areas are treated with a tool. Explicitly affected areas are removed, an antibiotic is applied to the sections. In wet and damp weather, processing is not carried out.

Fusarium and heterosporiosis of iris

Fusarium affects the vascular system of the plant. The causative agent is the fungus Fusarium oxysporum.
Most dangerous time for infections, these are temperature fluctuations in wet weather from + 2 ° С to + 32 ° С. soil infection high humidity, falls on the rhizome. The tissues soften, become covered with gray-brown spots. The root turns black and dries up. Prevention:

strict observance of the agricultural technology of the species;
feeding according to the norms;
do not injure parts of the plant.

Plants that have died or are affected by Fusarium are dug up. The place is treated with copper chloride. The rest of the planting is irrigated with any fungicides. Repeatedly follows on the site after 4-5 years.

Compliance with agricultural technology will help to avoid diseases of irises

In neglected iris plantations, with excessive soil moisture and a lack of phosphorus, heterosporiosis is activated. The causative agent of the infection is the fungus Heterospotium gracile. Diseased plants can be recognized by light brown oblong spots on the leaves. A severe infection causes the death of the leaves, but not the crop itself. Prevention:

neutral ph level on the soil;
timely removal of diseased and dead leaves;
application of phosphorus-containing fertilizers (superphosphate).

Gray rot and rust

Gray rot affects the stems. Occurs in cold and wet weather. It is dangerous if such conditions coincided with the beginning of flowering. You can recognize the disease by plaque on the buds and stems. Fabrics change color and darken. The causative agent is the fungus Botrytis cinerea. Prevention:

drained soils without stagnant moisture;
removal of fallen and dead parts;
gentle top dressing min. fertilizers (especially nitrogen).

As medicines horticultural fungicides are used (Topsin, Profit, Oxyhom).

Rust on iris occurs at cool temperatures around + 12°C. The causative agent of the disease is the fungus Puccinia iridis. The fungus releases spores on the leaves, resulting in complete death. Dark brown dust of a peculiar rusty hue is a sign of the disease.

Attention! The disease can occur if the storage conditions of the planting material are not observed.

Prevention:

cleaning flower beds from weeds;
compliance with the agricultural technology of the species;
timely detection of foci, treatment with fungicides.

Removing dead leaves

Harmful insects for iris

thrips. By sucking out the juices, they cause deformation and wilting of the iris. To fight, an emulsion of karbofos is used. The calculation is as follows: 75-95 g of solution per 10 liters of water.

nematode worms. Leaves infested with worms die off. Nematodes get on irises along with precipitation and from weeds. Prevention:

planting weeding;
disinfection of garden tools in formalin solution.

Bronzovka beetles. Beetles can be collected by hand. If their number is large, treat the plants with ash or Kinmiksom. Calculation of the drug: 2.5 g per 1 liter of water.

Aphid. Common cause mosaic diseases. Infected plants lag behind in development, have shortened peduncles and spots on the flowers. It is almost impossible to save an iris with a progressive mosaic. To combat aphids, drugs are used: Aktara, Inta-Vir. folk method- treatment with a solution of soda ash from households. soap.

Slugs. Against apply a mixture of lime and tobacco. Flowers are sprayed with tincture of hot pepper. The soil is freed from slugs by deep digging and removal of last year's plant residues.

scoops. Before the flowers bloom, the plants are sprayed with Bordeaux mixture. If caterpillars are found in flowers, then a decoction of hellebore Lobel.

Medvedki. For destruction, a soap solution is poured into the holes of insects (10 g of soap and 50 g of soap are taken for 10 liters of water). washing powder). Effective poisonous bait from a mixture of wheat grains, oil and karbofos.

wireworms. Roots hurt. Anhydrous ammonia is added to the soil to combat it and weeded regularly.

Early detection of the first foci of infection and pests, as well as competent agricultural technology - success in breeding the most exotic and "capricious" varieties of iris.

Many flower growers are of the opinion that irises do not give their owner any trouble at all. But is it? Iris breeding has come a long way in recent decades. Amazing in their beauty and sophistication varieties of irises were bred. Experience has shown that the more original and beautiful the variety, the more attention it requires to itself in terms of strict adherence to the basic methods of agricultural technology. Take a closer look at the area where you grow irises. If there is strong shading here, stagnant water, if the winter was little snowy and frosty - such plantings can be susceptible to diseases! Many amateur flower growers tend to buy an iris with a flower and transplant it to their site. You can understand them purely humanly - a person sees what kind of variety he is buying, but from the point of view of elementary agricultural technology of irises, this is unacceptable! The flowering period of the iris is the time of maximum use of nutrients. During this period, even the foliage stops its growth. If we disturb the peace of the iris during this period, then we will damage it root system and thus reduce the intake of water and other nutrients. We disrupt the development of new daughter blades of irises, thus harming the process of reproduction of the bush. Various harmful microorganisms multiply very actively during this period and, penetrating through the plant tissues damaged during transplantation into the root system, cause the plant to rot.

I would like to note that the development of iris diseases is greatly influenced by geographical position site and, accordingly, climatic conditions of growth. Already, the list of iris diseases is quite large and impresses the imagination. Is there a way out of this situation? Is it possible to protect our pets from bacteriosis of rhizomes, mole crickets, rust finally? It is possible and necessary!

If the grower follows the basic rules of agricultural technology, then he will be able to grow a healthy and viable planting material. First of all, I would like to draw the attention of our iris lovers to the need to propagate irises only from healthy bushes. If you notice signs of a viral disease on irises, immediately discard (destroy, in other words) such iris bushes. It is necessary to carefully monitor the plantings and promptly remove the rotten remains of the bushes. Delay in this case threatens with massive infection of the entire iridarium. Very nice results in the fight against such a disease of irises as fusarium gives the use of the drug fundazol. They can water plants (0.2% solution) under the root, as well as pickle individual rhizomes in it before planting. If there were prolonged rains in the summer, use a potassium permanganate solution after each such “wet” period. A solution of Bordeaux mixture will help you in the fight against iris spotting.

Not only iris diseases cause trouble for the grower, but also pests - gladiolus thrips, slugs, wireworms, hover flies, bears, and iris scoops.

Winter scoop and iris scoop. These pests eat away the bases of iris flower stalks, which leads to their yellowing and rapid death. After the scoops have taken over the bush, the iris can be affected by bacterial rot. To prevent the appearance of a scoop, treat the iris bushes with karbofos (10% solution) several times.

Thrips. Although this insect small sizes, but causes significant damage. Thrips settles in dense, unopened iris leaves, which makes them turn brown and dry. This pest loves not only iris leaves. After some time, he moves to the flowers. The buds of such plants bloom very sluggishly or do not bloom at all. Thrips do well in hot, dry weather. Against it, it is necessary to use the same solution of karbofos. As an alternative, you can offer an infusion of shag (about 0.5 kg) in a bucket of water. For better adhesion of this solution to iris leaves, laundry soap can be added to it.

Medvedka is a great danger for planting irises. The insect itself feels good underground, on the ground and even in the air, causing significant damage to plants, especially in the south of our country.

Ways to deal with a bear

If you add a little washing powder to a bucket of water and pour this solution into the minks where the bear moves, you can force it to crawl to the surface, where it can be easily collected by hand.

Don't throw away eggshell in winter. Collect it in enough, in the spring, grind into powder, add for smell sunflower oil and spread one teaspoon into the wells. Medvedka most often dies after tasting such a "treat".

Slugs. This clam has an excellent appetite. By the way, he loves bearded irises. The signal that slugs have appeared is the presence of silvery mucus on the leaves and oblong holes on them. Grows well in wet weather. Fallen, diseased, iris leaves are eaten with great pleasure. Then, crawling onto healthy plants, it infects them. To minimize harm from slugs, spread damp rags on the beds. The slug is nocturnal, so during the day it will probably use a damp cloth as a shelter. You can assemble it manually. Good results are obtained by using granulated metaldehyde.

Wireworm. Signs of the presence of a pest in the garden are long passages in the rhizome of the iris. The beetle itself is black, the larva is yellow or brown. To combat the wireworm, tinctures of insecticidal plants (bitter pepper, pyrethrum) are used. Tinctures should be aged before use during the day. For greater effect, add laundry soap to the solution.

Yet irises are more resistant to disease than other plants. However, a few words should be said about them. One of the most dangerous diseases is bacteriosis or soft rot of rhizomes. Signs of the presence of the disease: browning of the tips of the leaves and, as a result, their drying, growth retardation compared to other iris bushes. The leaves affected by the disease are easily pulled out of the fan, emit an unpleasant odor. The spread of the disease is facilitated by poor wintering of plantings of irises, high humidity and density of landings. Do not apply manure under irises - this also provokes the development of bacteriosis! If you notice such plants in your area, discard them immediately. Before planting, pickle the rhizomes in a weak solution of potassium permanganate. If you are transplanting irises, then after dividing the bush, open fractures must be sprinkled with ashes and the iris blade should be allowed to lie in the shade for 2–3 days so that the wound from the fracture dries up and heals. Do not plant irises in the same place all the time, observe the cultural rotation.

Fusarium and gray rot. Signs of diseases: rotting of roots and drying of rhizomes, transient yellowing of leaves and peduncles. These symptoms are caused by poor wintering, high humidity and excess nitrogen in the soil. To avoid this, it is necessary to plant irises in well-ventilated and sunlit areas, remove heavily affected bushes in a timely manner, pickle rhizomes before planting, and treat plants with fungicides.

Heterosporiasis (leaf spot). I think that every iris grower has observed signs of this disease in his area: brown-yellow spots form on the leaves, which leads to the drying of the leaves. Fortunately, the disease is not as dangerous as the previous ones, but it greatly spoils appearance irises. What can be recommended as a preventive measure? Remove iris leaves in a timely manner if they show the first signs of the disease. You can spray the affected plants with copper-containing preparations.

On the site, you can encounter such diseases of irises as rust, ascochitosis, septoria. As a preventive measure, it is possible to recommend a cultural rotation (the return of plantings of irises to their original place no earlier than after 5 years), as well as spraying with copper-containing, zinc-containing preparations and a suspension of colloidal sulfur.

Mosaic. This viral disease irises. Light shading becomes visible on the leaves, the petals become variegated. It is impossible to cure this disease. However, if you follow the basic rules of agricultural technology, you can try to hide the consequences of the disease. However, the plant will remain a carrier of the disease for healthy bushes. It is necessary to promptly discard affected specimens and deal with disease-carrying insects.

An important factor in the fight against diseases of irises is the disinfection of the cutting tool. The use of contaminated cutting tools is considered to be the main mechanism for the spread of iris diseases. This occurs during the division and transplantation of overgrown bushes, when the same knife or pruner is used to cut old rhizomes, roots and the upper part of the leaf fan at once on many plants of the existing collection.

To completely exclude the possibility of such infection, it is necessary to accustom yourself to divide each individual bush with a separate disinfected tool. Let me remind you once again that on the surface of cutting blades in dried cell sap, viruses retain their virulence for about 3–4 days, and the temperature of their death is approximately +72°C.

Methods for antiviral disinfection of cutting tools:

Ignition of the cutting part (blade) on an open fire for 1–2 minutes;
Sterilization in boiling water for at least 30 minutes;
Sterilization in pure (96%) technical or ethyl alcohol for at least 15 minutes;
Exposure in a 5% solution of potassium permanganate (pharmaceutical potassium permanganate) for at least 15 minutes (5 grams of KMnO4 per 100 ml of pure water);
Exposure in pure 40% formalin for at least 15 minutes.

When dividing and transplanting, use as little as possible cutting tools. It is better to simply break off a fan with a part of the rhizome from the old part of the bush. The leaves can not be shortened, and this will not affect the survival rate of the division. At the same time, do not touch with your hands oozing wound surfaces (cuts, cuts or fractures). Peduncles can be cut with the same tool, but with subsequent immediate manual removal of the remainder flower shoot. The rhizomes decaying during the growing season are cleaned to a healthy part and immediately sprinkle the entire wound with dry potassium permanganate and rub it over the entire wound surface.

With my article, I am not trying to scare iris lovers and plant a seed of doubt about the correct choice of irises as an attractive crop for growing. I can only say one thing: problem-free cultures do not exist at all. I try to act according to the principle: forewarned is forearmed. Our family has been dealing with irises for at least ten years and is quite successful. Iris is one of the most beautiful flowers that deserves your attention and admiration. I will be glad if the material presented in this article will help you to strengthen yourself in this thought.

Irina Orekhova was with you
Phone: 0662862622, 0952090093
Email: [email protected]

Unfortunately, this is the usual "runny nose" of irises - botrytis. Therefore, many iris lovers plant them in such a way that after flowering some other plants cover their unsightly foliage.
Here is an excerpt from the site of a collector friend of mine. What to do so that the leaf is always green
"Some agrotechnical methods of cultivation bearded irises in the conditions of the Moscow region
Among the bearded irises there are no "water lovers". They are afraid of excessive moisture, and only during the flowering period does the need for water increase.
Landings should be placed in sunny areas using raised beds of any configuration with a height of at least 20 cm. Further care is difficult in flat areas.
Heavy clay soils should be improved by adding sand and peat, strongly acidic - neutralized with ground chalk or ash. Fresh organic fertilizers it is dangerous to make, it is better - old 3-5 year old compost or humus
You can place rhizomes in one or two rows. The distance between plants is 30 cm for tall and 20 cm for dwarf irises. The distance between the rows is 50 cm. In the case of placement in 2 rows, good results are obtained by planting "back to back" (the cropped part - to the edge of the bed, a bunch of leaves - to the middle of the bed).
The whole season, the rhizome should be on the surface of the soil (only roots in the soil!) - this is a guarantee that in case of hot, humid weather this will not develop. dangerous disease like bacteriosis.
In the second half of October, plantings are cut "on a cone" at a height of 12-15 cm (as when planting), the rhizomes are covered on all sides with dry oak leaves, densely spudded with soil to a height of 7-10 cm (the height of the entire mound from the level of the beds). You can not use sand, sawdust, sphagnum, peat for shelter, as they strongly absorb moisture. To fully guarantee the preservation of flower buds in case of severe wintering, you can additionally cover with dense lutrasil / spunbond (grades 42 or 60), throwing it on a low wire frame made of wire or boards.
In the spring, immediately after the snow melts, the oak "coat" is removed, the leaves damaged by frost are cut off, and the rhizomes are freed from the ground. For prophylactic purposes, plantings are shed with a weak solution of potassium permanganate, Thiovit Jet or HOM preparation (copper oxychloride).
Feed with nitrogen fertilizers.
In case of May return frosts, you should always have on hand nonwoven fabric to protect flower buds from freezing. Cover only from frost!
Further care:
Watering - as needed.
Top dressing - in May and June with complex mineral fertilizers of the "Kemira" type, in July - with phosphorus-potassium. Excellent results gives the use of ash during the period when they are laid flower buds.
Against thrips: 2-3 times per season (in mid-May, early June, early July) - treatment with Actellik or any other drug against thrips.
In the phase of active growth of young rhizomes (after flowering), the so-called "stretching phase", when the extreme powerful leaves of irises are torn, giving rise to young roots and a young rhizome - it is especially important to ensure that the rhizome does not go deep into the soil and water does not flow into the cracks that appear . Otherwise, bacteriosis may develop. Aging, yellowing extreme leaves are regularly cut off at the very rhizome, cleaning out all their remnants.
After flowering, flower stalks should be carefully broken off or cut off at ground level. "