Brown spots appeared on the leaves of the irises. Fusarium and heterosporium iris

Rot of various nature becomes.

Bacterial rot (bacteriosis), or soft (wet) rot of iris rhizome

The most dangerous disease of irises.

Pathogens: bacteria of several groups (Erwinia aroidea, or Pseudomonas iridis), hibernate in soil or on plant debris.

When it appears: after the snow melts and in the summer after flowering, during the period of active growth of young daughter links. Excess nitrogen in the soil contributes to the development of the disease. Massive defeat is provoked by thickened plantings and dampness. The infection enters the tissue through damaged leaf bases (for example, after spring frosts) or root collar (with a deep planting).

Signs: at first, the rot is hardly noticeable. It usually starts with small area based on 1-2 outer leaves. The damaged parts become soft. Then the damaged leaves turn yellow, dry and are easily pulled out by the tip. The disease develops very quickly. Rot spreads deep into the fan, and then inward. Tissues soften, emit strong bad smell... With a strong defeat, the leaves lodge.

Prevention: we place irises in well-drained areas. We avoid mechanical damage to the rhizome and destroy pests. In the spring and in the second half of summer, we rake it off in order to prevent the deepening of the rhizome and the root collar warming up.

Wrestling: it is believed that bacterial rot is easier to prevent. Most often it is advised to destroy diseased plants. In the literature, it is recommended to use crushed activated carbon, a 0.5% solution of potassium permanganate and a suspension of captan, but these are all half measures, they will not allow the plant to be cured. Orchid growers use antibiotics to fight tropical bacterial infections. Application doxycycline on irises also gave amazing results. The plants managed to be cured completely, the first time, without digging up and without resorting to complex manipulations. The method is simple: regularly, starting in spring, the plants are examined. Suspicious places are powdered with medicine. If the disease progresses, the diseased tissue is removed, then the antibiotic is evenly applied to the sections. Processing is carried out in dry weather. For greater effectiveness, a broad-spectrum drug should be periodically changed (for example, lincomycin, penicillin).

Dry rot, or fusarium iris

Common fungal disease, as a result of which the vascular system plants.

Pathogen: mushroom Fusarium oxysporum.

Occurrence period: in humid weather with a wide temperature range (+2 ... + 32 ° С), the highest probability is at +12 ... + 17 ° С.

Signs: grayish-brown, slightly depressed spots appear on the surface of the rhizome, the rhizome rots. Rot is odorless. The affected tissues become loose, brown, later almost black, the rhizome dries completely. The source of infection is the soil, the risk of infection increases with increasing moisture content.

Prevention: compliance and recommendations for plant nutrition. We avoid mechanical damage to the rhizome.

Wrestling: dead plants are removed from the site, and the place where they grew is spilled with copper chloride. The remaining plants are treated with fungicides ( Vitaros, Previkur, Topsin-M). The return of landings to the old place not earlier than in 4-5 years.

Leaf spot, or heterosporiosisiris

A common fungal disease. It progresses in thickened plantings, with damp soil and phosphorus deficiency.

Pathogen: mushroom Heterospotium gracile.

Occurrence period: second half of summer in warm, humid weather.

Signs: the decorativeness of the leaves decreases - light brown oblong spots with a dark border appear on them. At strong development disease leaves dry up, but the plants do not die.

Prevention: removal of diseased and aging leaves, other plant residues, fungicide treatment. Feeding with superphosphate, maintaining neutral.

Wrestling: useful treatment with copper-containing preparations and fungicides ( Strobe, Ordan), foliar feeding calcium nitrate.

Gray rot iris stalks

Pathogen: mushroom Botrytis cinerea.

Occurrence period: in cool, wet weather during flowering.

Signs: tissues of buds and stems lose color, turn brown and become covered with a gray mold-like bloom.

Prevention: sparse planting on well-drained soils, timely destruction of plant residues. Do not overfeed with nitrogen. Fighting: with drugs Topsin-M, Profit, Oxyhom, Kuproskat.

Gray rot of iris rhizomes

Pathogen: mushroom Botrytis convolute.

Occurrence period: in wet weather, especially at relatively low temperatures.

Signs: in spring the plants start growing very slowly. In the summer, the entire fan dies off. Dry rot forms on the rhizomes. In wet weather, the rhizomes and leaf bases become moldy.

Prevention: removal of damaged rhizomes along with adjacent soil, disinfection of holes, change of planting site.

Wrestling: drugs Maxim, Bordeaux mixture, Topaz, Oxyhom, Kuproskat.

iris

Pathogen: mushroom Puccinia iridis.

Occurrence period: optimum temperature for the development of the fungus +12 ° C.

Signs: the leaves have brown stripes covered with rusty dust (fungal spores). The affected leaves dry up.

Prevention: regular, correct agricultural technology, timely treatment with fungicides.

Wrestling: with drugs Strobe, Topaz, Ordan, Bordeaux mixture.

Heterosporia , or leaf spot, the causative agent is a fungus Heterosporium gracile.

Signs of the disease. On the leaves appear oblong grayish brown spots with a darker border. With a strong development of the disease, the leaves dry out. The disease does not spread to the rhizome.
Control measures. Destroy plant residues and dried leaves. Spraying with cuproxate is applied. Plants are treated with copper-containing preparations, for example, a suspension of copper oxide (0.3%) or Bordeaux liquid with the addition of adhesives. Bordeaux liquid (1-1.5% solution) can be prepared independently: 100 g copper sulfate and 75 g of slaked lime per 10 liters of water. The soil around the plants is also spilled with a solution of copper-containing preparations. Spraying with fungicides is also effective. It must be remembered that you need to use only those drugs that have received permission for use in personal subsidiary plots. Combined treatment combines protection against heterosporia and harmful insects.
Prevention. To increase the resistance of irises to this disease, spring spraying leaves with a solution of calcium chloride or calcium nitrate. Calcium helps to increase the strength of the cell walls, and thus, plants become less susceptible to disease.
For protection against leaf spots, progressing in rainy weather, preparations are very effective new group strobilurins (synthetic analogs of the waste products of some fungi), such as strobe, which feature is that they are not washed off by rain for an extended period of up to two weeks. However, strobilurins should not be used more than twice a season and should be alternated with contact agents such as copper oxychloride. Strobilurins, like contact fungicides, have only a protective effect. They do not destroy pathogens, so they must be used before the spread of diseases.

Rust , the causative agent is a mushroom Puccinia iridis.
Signs of the disease... In late summer - early autumn, brown stripes appear on the leaves, which, when touched, leave rusty dust on the finger. Affected leaves dry out prematurely.
Control measures... Large plant residues are destroyed, small ones - they are embedded in the soil during its processing or the areas are mulched with peat, humus or sand with a layer of 2-3 cm. In this place, irises can be planted no earlier than 3 years later. Spraying with copper oxychloride, cuproxate (1%), colloidal sulfur with adhesives is used.
Prevention... The resistance of plants to rust is increased by phosphorus-potassium supplements. The disease can be prevented by sprinkling the plants with Bordeaux liquid in the middle of summer.

Wet , or bacterial, rot, bacteriosis ; pathogens - bacteria Pectobacterium carotovorum, Erwinia aroidea, Pseudomonas iridis. This disease affects bearded irises and especially often develops when growing plants in conditions of high humidity, on heavy soils, with deep planting of plants and with freezing of rhizomes.

Photo by L. Treivas from the magazine "In the world of plants" - 2002 - №6

Signs of the disease... The leaves turn pale, and then dry up and turn brown. The fan of leaves tilts and then falls to the ground. Rhizomes and leaf bases darken, decompose, turning into a mushy, unpleasantly smelling mass. Plants die.
Control measures... The plant is dug up, its aboveground part is destroyed, the soil around is loosened and treated with a solution of a permitted fungicide. The rhizomes are cleaned to healthy tissue, the sections are washed with a strong solution of potassium permanganate and covered with Novikov's liquid (brilliant green with glue) or sprinkled with crushed charcoal or ground sulfur. The causative agent of rot dies in direct sunlight, so the cut can be dried in the sun. Plants are transplanted to another site. When transplanting, the rhizomes are washed in a solution of formalin (1: 300) or quinosol (0.2%). Effective method the fight against wet rot is also soaking the rhizomes in a 0.01% solution (1 tablet per 1 liter of water) of the antibiotic tetracycline for about 1 hour. First, the rhizomes must be dried in the sun - then they better absorb the drug. Prevention. It is possible to prevent the occurrence of this disease by observing the rules of iris agricultural technology. The main thing is not to overmoisten the plantings of irises and make required amount phosphoric and potash fertilizers... For preventive purposes, you can also spray on green foliage with a solution of urea with the addition of sulfur (12%), approved fungicides or sodium thiosulfate solution (neutral photographic fixer), which decomposes in the soil to form sulfur.
Preventive measure, effective in years with humid summers, are watering the soil with solutions of antibiotics: tetracycline or streptomycin sulfate (agrimycin), which are prepared by diluting 30 g of the antibiotic in 10 liters of water. 60 liters of solution are poured onto 1 m2 if the soil is coarse-grained, and 80 liters if the soil is fine-grained. Watering is carried out every 10 days.

Gray rot, botrytis ; causative agent - mushroom Botrytis cinerea... The disease is caused by two types of fungus. The first affects the stems and ends of the leaves when high humidity... The second type of fungus causes dry rot of rhizomes. The disease develops in conditions of high humidity, with an excess of nitrogen in the soil, with freezing of the rhizomes and the presence of mechanical damage.

Affected plant

Photo by L. Treivas from the magazine "In the world of plants" - 2002 - №6

Signs of the disease... Peduncles and leaf tips become discolored, and then turn brown, rot, become covered with a smoky gray coating of the fungus. Black folded piles consisting of sclerotia of the fungus form on the affected rhizomes. Rot can spread to the base of the leaves, where a gray coating of fungal spores forms.
For prevention gray rot irises are recommended to be planted in well-drained, ventilated sunny areas. Avoid lack of phosphorus and calcium in the soil. Severely affected specimens are discarded. When symptoms of the disease appear, the plants are sprayed with fungicides. When planting, the rhizomes are etched, the affected areas are removed. It is necessary to disinfect contaminated soils.

Scorch , the causative agent is presumably mycoplasma.
Signs of the disease... The leaves turn brown in the middle of the growing season, their ends, drying out, bend, the roots die off, the rhizome hardens and dries up.
Control measures... Plants are usually dug up and destroyed, and the soil is treated with lime or formalin.
Prevention... Sometimes the affected bushes are restored in the second or third year from dormant buds, but the main preventive measure this disease is the early division (cutting) of the bushes into several unrelated parts. In this case, a transplant is not necessary. Scorch is not transmitted to neighboring, already isolated plants.

Ascochitosis leaves are caused by a fungus of the genus Ascohita. The spots are brown, without bordering, with numerous black punctate pycnidia.

Septoriasis leaves are caused by a fungus of the genus Septoria. The spots on the leaves are pale gray, with a brown border, small, rounded. Black pycnidia appear on the surface over time.

Ramulariasis leaves are caused by a fungus of the genus ramularia. The disease manifests itself as brown or even black small, rounded spots, which fade over time in the center. A weak yellowish bloom of the mycelium appears on necrotic spots.

Mosaic - viral disease. On the leaves, a pattern is formed in the form of a grid or yellow stripes, reminiscent of a mosaic. Plant growth slows down, shortened peduncles are formed, flowers are underdeveloped. The flower petals become variegated. The disease is spread by aphids.

Photo from the magazine "Floriculture" - 2001 - №3

If the irises are infected with viruses, they cannot be cured. Only preventive measures are taken. Good care helps to mask the symptoms of the disease, but the plants will be a source of infection for the healthy. Timely culling of diseased specimens is necessary, as well as the fight against insects - carriers of viruses (aphids). In the photo on the left there is a streaky mosaic on iris leaves.

Other related materials

Irises are among the most resistant to diseases and pests. ornamental plants... These flowers are a favorite selection object of many summer residents (here is an article about them), in the process of breeding new varieties of which it was discovered that the most exquisite irises are most susceptible to various diseases and pests. At the same time, there is a clear delineation of the incidence of diseases in flowers, depending on the climatic zone. So in the north-west of Russia, irises are most often affected soft rot(bacteriosis), and in the southwest - rust.

Irises affected by viral diseases do not respond to treatment. They must be dug up and burned. Special attention should pay attention to the safety of plant tubers, since they are often damaged by various diseases and a variety of gnawing insects. Compliance with all the requirements of agricultural technology and the use of safe planting material allows you to minimize the risk of damage to summer flowers by diseases and pests.

Iris diseases

The most dangerous diseases for these flowers are:

1. Fusarium

Signs: the leaves turn yellowish, and then acquire a brownish tint.

Control measures: add 0.2% Fundazol under the rhizomes of irises. Before planting young plants, rhizomes are disinfected in this solution for 0.5 hour.

2. Spotting

Signs: spots of various shades appear on the leaves and stems of the iris.

Control measures: spray flowers with 1% Bordeaux liquid solution or 0.3% copper oxychloride.

3. Septoriasis / heterosporiasis

Signs: yellowish spots of various sizes appear on the leaves of the iris. Later they turn brown and merge. The leaves dry out, and the plants do not bloom well. The disease most often develops in damp weather, as well as with a deficiency of phosphorus and calcium in the soil.

Control measures: at the first signs of the disease, spray irises with 0.3% copper oxychloride; 0.4 - 0.5% colloidal sulfur.

4. Wet rot (bacteriosis)

Signs: the rhizome rots, the tops of the stems turn yellow and dry out. They show clear signs of decay. After a while, the affected parts of the plant die off.

Control measures: we dig up specimens affected by this disease and burn them. We disinfect the soil with formalin.

Iris pests

The most common for this type of flowers:

Signs: most often bearded and Siberian varieties... The disease progresses rapidly in hot weather. Insects gnaw at the base of the peduncles. Caterpillars of these pests gnaw at the rhizomes. Such insects increase the risk of bacterial rot damage to plants.

Control measures: at the beginning of the period of active growth, we twice process the flowers with 10% karbofos. The interval between sprays is 7 days.

2. Medvedka

Signs: areas damaged by the bear are visible on the tubers. With large "wounds", the iris can dry out altogether.

Control measures: we fill the earthen passages of this insect-pest with soapy water, and after the bear crawls out of the hole, we destroy it. Next to the iris bushes, we embed granules in the ground - bait for these insects: Medvetox, Thunder, Grizzly. Medvedka eats soaked granules better, so we water the earth around the flowers.

Signs: These microscopic insects take up residence in the tightly compressed leaf entrances of the plant. Irises damaged by pests are distinguished by their brown leaves, which dry quickly and become covered with dark crusts. Thrips also damage buds, causing tissue discoloration and flower deformities. Most often, such pests appear in hot weather.

Control measures: we spray the bushes with 10% karbofos twice. The spraying interval is 7 days.

Signs: These molluscs eat flowers, and sometimes damage the young leaves of the plant, leaving oblong holes on them. They reproduce especially strongly in wet weather.

Control measures: we collect slugs by hand and destroy them. We spray irises with tobacco infusion or superphosphate. Spread metaldehyde on the ground (40 g / 10 sq.m.), which is harmful to these pests.

5. Wireworm

Signs: these larvae of click beetles eat up passages in the rhizomes of flowers, thereby increasing the risk of their being affected by various diseases.

Control measures: we perform deep podzimny digging of the soil. We spray the bushes with infusions of red bitter pepper (we steam 100 g of chopped pods with 1 liter of boiling water, we cook the infusion for 1 hour, we insist it for two days). We also pollinate irises with Pyrethrum (200 g / bucket of water we insist for 10 - 12 hours and spray with a solution of the plant).

Signs: the larvae of this pest gnaw at the rhizomes, thereby inhibiting the growth and development of flowers.

Control measures: when digging the earth, we remove the larvae manually. Before planting rhizomes of irises, dip them in a mixture of liquid clay and Bazudin (100 ml per bucket of water).

7. Nematodes

Signs: plant tissues damaged by the pest acquire a brown tint.

Control measures: we burn the damaged specimens. The place where they grew is watered with 10% formalin solution. Before planting rhizomes, we warm them up in warm water(50 ° C) for half an hour.

Such beautiful flowers as irises are loved and widely cultivated by flower growers and gardeners in various natural and climatic zones of our planet. Varieties of this plant, adapted to the most different conditions, many, and on their basis breeders have created delicious varieties.

This article will tell you about the various types of this flower, the features of care and reproduction, as well as what pests and diseases of irises are found.

Who gave it a name?

The famous ancient Greek philosopher and healer Hippocrates named this flower for the variety of its colors in honor of the goddess Iris. It was she, like the rainbow, who connected heaven and earth, proclaiming the will of the gods to people. In addition, in the ancient Greek language "iris" meant, first of all, a rainbow, and then in the 18th century the naturalist Carl Linnaeus, who created a unified system of classification and names of plants, retained its ancient name for iris. Before talking about what diseases and pests can affect irises, we will briefly dwell on biological characteristics of this plant.

Botanical description

Flowers such as Iris, better known to gardeners as brewers or iris, belong to the Iris family. As a rule, these are perennial rhizomes, but corms are also found.

In our strip, the most common rhizomatous representatives of iris, rather unpretentious to care for and moderately water-loving. Iris garden forms a thick rhizome, located shallow underground and quite often protruding from it, with big amount thin filamentous roots. The flat leaves of this flower are dense and rather rigid, covered with a whitish waxy bloom of a xiphoid shape. In most iris species, they grow in fan-shaped tufts. planting and caring for which is carried out in accordance with the characteristics of the plant, bloom from late spring to mid-June.

Features of flowers

In all types of irises, flowers are located on a strong and strong peduncle. In most cases, the flowers are solitary, but they are also found in small inflorescences. The color can be very diverse - from snow-white to almost black. Today there are varieties whose flowers are painted in two or even more colors. Such an iris flower consists of six, and sometimes three petals, the inner and outer lobes of which differ in shape, size and color.

After flowering, the plant forms a fruit - a ribbed triangular elongated box, in which there are about 20 large seeds brownish color.

What types are there?

Foreign breeders and flower growers subdivide all iris plants grown in gardens into 13 main groups, although some believe that there are about 17. In our country, it is customary to subdivide garden forms Iris (iris) into the following 10 main groups:

• bearded;
• Siberian;
• Japanese;
• repairing;
• arylbreds and aryl;
• spuria;
• Louisiana;
• Evansia;
• plants of the Pacific coast;
• little known.

Such a classification is really needed, but in ordinary life accepted a simpler and more understandable division of all rhizome irises into two groups: bearded and non-bearded. The most common in gardens are large, exquisitely painted representatives bearded irises... These include many varieties of the so-called Germanic tall bearded irises.

Unlike bearded irises, on the lower petals of which there is a "beard" of contrastingly colored villi, non-bearded irises do not have such decoration. This group includes the following types of irises:

Siberian (I. sibirica);

Marsh (I. pseudacorus), it is also called pseudoair;

Japanese (I. japonica);

Louisiana (I. Louisiana);

Spuria (I. spuria);

Californian (I. californian).

We will try to briefly describe each of the listed types.

Iris barbata

Bearded iris is the most popular of the entire iris group. Today, there are about 35,000 varieties of it, and several new ones appear every year.

This flower got its name because of the delicate villi located on the lower petals. In many varieties, the beard color contrasts with the basic color of the six-petal flower. By height, bearded iris is divided into three groups:

1. High - more than 0.7 meters;
2. Medium height - from 0.4 to 0.7 m;
3. Low, the height of which does not exceed 40 cm.

Coloring of flowers can be both monochromatic and combined. The group of bearded irises includes

Siberian Iris

Unlike the hardy and unpretentious species Siberian iris, the varieties bred on its basis have a higher need for heat and light. Plants in this group can grow up to 1 meter in height. Their leaves are narrower than those of bearded ones, and have a lighter color. Varietal representatives come in various colors and bloom in late spring. You can choose varieties so that flowering will continue until the end of July. Diseases of cultivated and varietal irises are not terrible for him, and he is rarely affected by pests.

Pseudoair (marsh) iris

It opens its golden yellow flowers with small brown "strokes" in late May - early June. This type of irises grows well in shallow, up to 40 cm, reservoirs, as well as on their borders. It develops well both in the sun and in partial shade.

In the middle lane, types of irises such as Californian, Louisiana, Japanese and spuria are rare, since there are few varieties adapted to our conditions, and they are, due to their rarity, not cheap.

Iris flowers: planting and care

When buying irises, you need to clarify what kind of irises you are getting, as this affects the choice of a place for planting. Most modern varieties of irises, both bearded and non-bearded, prefer sunny, warm, sheltered from the wind. However, species such as marsh, smooth and bristly, are Smooth and marsh irises, as well as varieties derived from them, it is recommended to plant in shallow water artificial reservoirs, and bristly - on flooded shores or in wet lowlands.

Other types of irises are planted in conditions middle lane in spring or autumn, and the most favorable period is considered to be the end of summer - the first weeks of autumn. Before planting the rhizomes of these flowers, the soil must be dug to a depth of 20-30 cm, and phosphorus-potassium and nitrogen-containing fertilizers and humus must be added. After the irises have been planted, leaving for open ground behind them is regular watering and feeding, removing weeds as needed.

It is necessary to plant these plants every three to five years, since individual fragments of the rhizome are forced out to the surface as they grow. Because of this, the feeding area decreases and they stop blooming. It can also lead to the development of iris disease.

How to propagate?

These perennial plants can be propagated both by seeds and vegetatively. The seed method is used when breeding work and the plants obtained in this way bloom in 2-3 years.

More simple and affordable way reproduction of irises - vegetative, in which the rhizome mother plant divided, and then the resulting plots are planted in the soil. It is best to transplant and divide this perennial two to three weeks after the end of flowering. Plots are planted superficially and slightly obliquely - so that the top of the rhizome is above the ground. Planting too deep can provoke the development of iris flower disease and even cause their death. Plants obtained in this way bloom in the first year after planting.

Disease Signs and Control Measures

Most of the plants of this group are quite resistant to diseases, but with unfavorable weather factors and various damage to the rhizome, the following diseases of irises can occur:

1. Heterosporia (septoria), manifested in the form of different-sized yellow spots, randomly located on the entire surface of the sheet plate. At further development disease spots become brown and merge into one. The plant looks weak, blooms poorly, and the leaves dry out. Heterosporia develops with a lack of calcium and phosphorus in the soil. Also, its development can be caused by prolonged rainy weather and the accompanying high humidity... Spraying the plants with a 0.4% solution or 0.3% helps in the early stages of this disease of iris flowers.
2. Bacteriosis (wet rot)- the most dangerous disease, as it develops quite quickly. The first "symptoms" of this disease are drying and yellowing of the leaves. Then the base of the "fan", and then the rhizome is affected by rot with a characteristic unpleasant odor... The cause of bacteriosis may be an improper planting - excessive deepening or too dark and waterlogged place. At the first signs of damage to this disease, you need to dig up the plant and remove the affected part of the rhizome. Treat the "operation" site with potassium permanganate, and then any growth stimulant. After that, we dry the rhizome well, and then plant it separately from the rest of the plants in dry soil, trying not to deepen it.
3. Fusarium... With this disease, the iris continues to grow and even blooms, but the leaves first turn yellow and then turn brown. To prevent the development of this disease, before planting, the rhizome is disinfected in a 0.2% solution of foundationol for half an hour. If struck flowering plant, then pour the same foundationol solution under the rhizome.
4. Leaf spot may appear due to bad weather conditions. The first signs are spots different color and size on the leaves. Noticing them, immediately spray the diseased plant with a 0.3% copper oxychloride solution or 1% Bordeaux liquid composition.

Pests of flowers

Irises can be affected by diseases and pests. Among insects, these are:

• Medvedka, gnawing rhizomes with pleasure. To combat it, you can use special bait granules, burying them in the ground around the iris plantings.
• Iris (winter) scoop. The caterpillars of this insect feed on the rhizome, and the adults gnaw out the bases of the peduncles. Such an attack promotes the development of bacteriosis of irises. During the period of active growth of flowers, it is necessary to spray them with an infusion of wormwood: a glass is laid in 10 liters of boiling water wood ash, a tablespoon of any liquid soap and 300 g of grass. The container with the solution is closed and left to infuse for 5-6 hours. Immediately thereafter, use for spraying. You can also use a variety of biologics sold in specialized stores.
• Iris flower girl, outwardly resembling the most common fly, spends the winter in the ground, but in the spring it crawls out and lays its eggs in the buds. This is how irises are affected. Diseases of the buds and their death occur due to the larva inside and actively feeding. The affected bud rots and, of course, does not bloom. Experts recommend that plants must be treated when leaves appear, as well as at the beginning of the budding stage with special insecticides. Affected buds should be immediately cut off and destroyed.

In addition to the above pests, irises can be affected by slugs, May beetles, wireworms, different kinds thrips and nematodes.

And although irises can be attributed to unpretentious plants, they are very often exposed different diseases... Therefore, the gardener needs to constantly take care of the quality conditions for the growth of flowers. By improving conditions as much as possible, you can reduce the risk of disease.

Every gardener should be familiar with various diseases that can harm the plant. In order to prevent this, you need to know the reasons for their occurrence.
Iris diseases most often occur due to:

• too high soil moisture;
• if there are old bushes and the plant requires rejuvenation;
• excessive use of organic fertilizers;
• consequences after a severe cold snap or frost.

More about iris diseases

Diseases of irises and the fight against them photos can be seen both in the magazine and on the Internet. Every plant lover who is going to grow them in the garden or on the site near the house should know about diseases. The most common ailment that occurs is bacteriosis. It is characterized by the defeat of the rhizomes.

The disease causes rotting and an unpleasant odor. Such a disease most often occurs due to a decrease in temperature to 3-5 degrees. If you do not take measures, their treatment in the late time will not give results.

To avoid such a disease, you need to carefully examine the bush, it is better to do this at the end of winter, during the snow melting period. To prevent bacteriosis from developing on irises, they must be protected as much as possible from melt water.

In order to do this, you can use raised beds or plant plants on a natural slope. If rot is found near the rhizome, it must be removed immediately.

Then carry out the processing of the rhizome, for this you can use a 10% solution of bleach. If possible, you can use a solution of potassium permanganate. Such effective means quickly help eliminate the signs of bacteriosis.

• One of the most dangerous diseases irises - fusarium. The disease appears due to a fungus, affecting both the roots and stems. Too much nitrogen in the soil is considered to be the main cause of occurrence. May occur due to lesions of the plant tubers. Fusarium often appears where there are unfavorable climatic conditions.
• If we talk about what the disease looks like, then, in appearance, grayish brown spots begin to appear on the plant. The plant may appear slightly shriveled. If the treatment is not carried out immediately, the irises for a short time acquire a brownish tint. Best used for treatment chemical agents that will not injure the plant.
• Another disease that occurs in irises is heterosporiasis. A disease that can affect the stems and leaves of irises. Most often it begins to spread from the old foliage of the bush. The disease is easy to spot as grayish-white spots begin to appear. A yellowish border also appears on the leaves. If the disease is not eliminated, the plant may die. To prevent heterosporia, potassium and phosphorus are used with the addition of various trace elements. Such substances help the plant to become more resistant and resist infection. In addition to using the product, do not forget about cleaning the land from weeds, as they can negatively affect the irises. Before processing, it is necessary to clear the bush from infected leaves and use treatment products.
• Fungal diseases include botrytis, which is considered quite dangerous and often leads to the death of the plant. It often arises due to poor storage of planting material (especially if there was poor ventilation of the room and high humidity). The disease occurs after planting a plant and begins to actively develop in the soil. To prevent this from happening, you need to store planting material in a dry room with adequate ventilation. And before planting, it is best to treat the rhizomes of the plant with special systemic fungicides.
• Also, of the fungal diseases that are common in irises, there is rust. The reason why the leaves turn yellow is hidden just in such a disease. The disease develops at a temperature of +12 degrees. If left untreated, iris leaves dry out quickly and fall off. To eliminate fungal disease, the affected leaves must be plucked and burned. This is necessary in order to completely eliminate the fungus, since it can remain in the soil for many years and appear immediately after the snow and frost melt. In addition, rust can easily attack other plants growing near the iris.

Other Common Iris Diseases and Their Treatment

In addition to fungal, the plant can be affected by mycoplasma and viroids. Such diseases differ in their effect on the bush.

Virosis is a dangerous viral disease, and the first sign of its small wrinkles, folds and blistering on the leaves. The disease can affect the color of the petals. Virosis also leads to frequent fragility of the peduncles.

To fight the disease, the gardener must completely destroy the planting material that has been infected. For prevention, it is recommended to use fungicides to eliminate phytopathogenic fungal diseases.

All gardeners should be aware that iris diseases and their treatment are caused by nematodes. And among the most dangerous are:

1. Stem;
2. Gallova;
3. Potato golden.

Nematodes have the ability to infect rhizomes and provoke rotting. It is worth noting that such a disease can affect the growth of a plant and significantly inhibit it. To prevent the plant from being affected by the disease, gardeners recommend regularly cleaning your area of ​​weeds.

Many gardeners wonder why the disease occurs, because the planting material was of high quality and was stored in good conditions, fertilizers were used, but diseases of varying degrees of complexity still overtook the plant.

Here the whole matter may be in the soil. Poor quality soil, lack of components and minerals, such as potassium, phosphorus, nitrogen, can cause diseases.

But, it is important to take into account the fact that these substances can affect the state of the plant not only positively, but also harmful. In addition, iris can be affected by a variety of diseases if the air temperature is either too low or too high.

Pollution level environment also plays a very important role. Another reason for the appearance of various diseases can be a lack of oxygen in the soil.

Pests that impair the growth of irises

Diseases and pests of irises are what can provoke the rapid death of a plant. If we talk about pests, then this is a very serious issue, and every gardener should know what pests can infect iris and how to deal with them.
Do not assume that only diseases can destroy the bush, pests in this regard also bring great harm.

The most dangerous pest is thrips. Such insects can not only damage the leaves, but also the rhizomes. But, it is possible to cope with such insects, for this each gardener needs to regularly clean his land plot from weeds.

In the event that insects have damaged large areas of the territory, various preparations must be used. All chemicals can be bought at a garden store, in each case, you need to use a separate drug. To combat thrips, organophosphorus agents are used.

Of the harmful insects, aphids are also dangerous. Among its features is that it infects leaves, flowers. The insect multiplies quickly, which makes it difficult to fight for the plant.

To combat the pest, it is recommended to use 0.3% carbaphos emulsion, 15% phosphamide emulsion and 0.5% soda ash solution with soap solution. When fighting aphids, do not forget about cleaning the area from weeds, which is also an effective method.

Diseases, pests - all this can cause poor growth of irises in your area.

To avoid difficulties with growing, it is worth using the advice of experienced gardeners:

• so that irises do not suffer from diseases and pests, it is worth digging up the soil regularly;
• apply pesticides;
• store planting material correctly;
• monitor humidity and temperature. Additionally fertilize with useful substances.

Among the harmful insects that can impair the growth of iris are larvae. May beetle... They can damage the rhizomes and tubers of the bush. To control pests, you need to regularly dig up the soil and collect all the larvae. It is recommended to apply pesticides before planting irises.

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