How to treat rust on trees


How to Get Rid of Rust Fungus on Plants

By

Jamie McIntosh

Jamie McIntosh

Jamie McIntosh has written about gardening and special occasion flowers for the Spruce since 2011. She has more than 20 years of experience caring for flowers and plants. She was a feature writer for Organic Gardening at Suite101, where she won awards for her writing.

Learn more about The Spruce's Editorial Process

Updated on 12/13/21

Reviewed by

Debra LaGattuta

Reviewed by Debra LaGattuta

Debra LaGattuta is a gardening expert with three decades of experience in perennial and flowering plants, container gardening, and raised bed vegetable gardening. She is a Master Gardener and lead gardener in a Plant-A-Row, which is a program that offers thousands of pounds of organically-grown vegetables to local food banks. Debra is a member of The Spruce Gardening and Plant Care Review Board.

Learn more about The Spruce's Review Board

Betsie Van Der Meer / Taxi / Getty Images

On cars, a little rust can turn into a lot of rust in a short time when the rust spots combine into a bigger problem. Gardeners face a similar issue when rust fungus affects a plant; a small outbreak can quickly spread and affect the appearance of an entire plant. Rust disease does not affect a plant's general health and is usually not fatal, but you should learn how to get rid of rust fungus once and for all.

Rust Fungus Identification

Many types of rust fungus disease affect specific annual and perennial flowering plants, but no matter the rust disease, gardeners can recognize this problem by observing the speckled masses that form on the surfaces of leaves. Like the namesake, many of these pustules are rust-colored, but gardeners should also suspect rust if they see brown, orange, purple, red, or yellow dry spots on foliage.

Rust spots are usually tiny and scattered across plant foliage like freckles. Affected plants can have dozens of rust spots on each leaf, and it’s possible for a single leaf to have more than a hundred rust spots.

Commonly Affected Plants

Rust disease often affects Alcea rosea (common HollyHock), but hollyhocks aren’t the only potential victims of this fungus. Pay close attention to the signs of rust fungus in the following plants during the summer months:

Damage Caused

Plants with a heavy rust infestation might experience curling or withering of leaves, and the plant can lose its leaves entirely. If this much damage occurs, you can expect to see stunted plant growth.

How to Water Plants to Prevent Rust Fungus

Rust fungi, like many fungal plant diseases, flourish in wet conditions. The most important step you can take to reduce rust in your flower garden is to stop overhead watering. Instead, use a drip irrigation system or a watering wand to deliver water at ground level. If this isn’t possible, water your flower garden early in the morning when the sun’s rays will quickly dry your flowers’ foliage.

Tips

Practicing good garden hygiene can decrease rust attacks. If you see signs of rust, remove and destroy the affected foliage to prevent the spores from spreading. Do not place diseased foliage into your compost pile.

Control by Organic Methods

A weekly dusting of sulfur can prevent and treat rust fungus. Neem oil, a botanical fungicide and pesticide, also controls rust. Some organic gardeners swear by baking soda to control garden fungus. The efficacy of baking soda spray might be enhanced by mixing it with light horticultural oil.

Control with Commercial Fungicides

You can choose several commercial fungicides to control rust fungus. Apply the sprays when you see the first signs of disease and continue applications according to package directions through July. Look for commercial fungicides that contain these active ingredients:

  • Chlorothalonil
  • Mancozeb
  • Myclobutanil
  • Trifloxystrobin

If you are unsure about the active ingredients that would work best to control a rust issue in your garden, contact your local Cooperative Extension Service for recommendations.

Choose Rust-Resistant Varieties

Hybridizers are continuously developing new flower varieties resistant to rust fungus. If you’ve experienced rust for multiple growing seasons, it might be time to remove susceptible plants and replace them with these proven varieties:

  • New England Asters ‘Honeysong Pink’ and ‘Purple Dome’
  • Hollyhock 'Happy Lights’
  • Snapdragons 'White Monarch’ and the Rocket series

Even if you plant rust-resistant varieties, you must give them enough room to grow. Proper plant spacing increases air circulation that enables plants to dry more quickly. Overcrowding plants and dampness are the perfect conditions for many fungal diseases.

Watch Now: 7 Tips for Every Gardener

Article Sources

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Snapdragon – Rust.” Umass.Edu, 6 Mar. 2018, https://ag.umass.edu/greenhouse-floriculture/photos/snapdragon-rust

  2. Purdue Agricultural Communications Service. “Purdue Agriculture - Plant and Pest Diagnostic Lab.” Purdue.Edu, https://ag.purdue.edu/btny/Herbaria/Pages/Arthur%20Herbarium/The-Rust-Fungi.aspx

  3. Rust Fungi. Purdue University Extension

  4. “Rust in the Flower Garden.” Umn.Edu, https://extension.umn.edu/plant-diseases/rust-flower-garden

  5. cagobotanic.Org, https://www.chicagobotanic.org/downloads/planteval_notes/no36_asters.pdf

Identify Symptoms to Treat and Control Rust Disease

There are around 8,000 named species of rust diseases, many of them host-specific. Scientists speculate there are many more types of rust diseases in the tropical and subtropical regions of the world that have not been discovered yet. Rust diseases are an important class of plant pathogens that affects many economically important crops, including cereal crops, flowering plants, and ornamental plants. Biologists think rust fungi are very ancient to have had the opportunity to co-evolve with so many plants.

Because rust fungi are obligate parasites, they will only live on living plants. The fungi creates a structure called a haustorium out of the fungus cell wall and the plant cell wall, which is where the food from the plant goes to the fungi. Even if the fungus is given all the food it needs, it will not grow in a petri dish without the living plant cell of its plant host. This makes it difficult to grow it in the lab, so there are things scientists just don’t know about it yet.

Rust does not usually kill its plant hosts, but can severely limit the growth of plants and their production of food for people. The Irish potato famine was caused by a species of rust that rotted the potatoes in the ground or in storage into a goeye mess. Not only did many Irish starve, but the influx of the Irish into the United States was also caused by that famine. Rust has contributed to other famines through history.

What is Rust Disease?

Rust disease is an obligate fungal parasite that grows on a wide variety of plants useful to humans. All rust fungi are in the order Pucciniales (formerly Uredinales) although there are many types of individual rust diseases. Most of these types can only grow on one or two species of plant.

Symptoms of Rust Fungi

The signature symptom of rust is the orange, yellow, brown, or red spore masses on the outside of the plant. This color gives the rust fungus its name. These spores appear as raised dots on the leaves or stems of the plant. Some types of rust form galls that then become covered in the spore masses. Rust occasionally forms on blooms.

Symptoms occur from the ground up. They are usually on the underside of the leaves but may also appear on the top of them. It may cause witches broom growth (redish, twisted stems and leaves), cankers, oozes, and spotted needles. Rust may cause leaves to fall prematurely. If enough of the leaves fall, the plant may die. Plants may be stunted, off color, and weak. Plants that are heavily affected for 2-3 years in a row may die if not treated. A bad case of rust does not leave enough green areas on the leaf for significant photosynthesis to occur, and the plant starves.

Rust may occur on the bark or needles of conifers. It may cause witches broom growth (redish, twisted stems and leaves), cankers, oozes, and spotted needles.

Some types of turf grass get rust, too. If you walk through the lawn and your shoes have orange dust all over them, you have a rust problem. This is most common in perennial ryegrass, but also effects Kentucky Bluegrass, tall & fine fescues, zoysiagrass, and bermudagrass. You can find rust resistant turfgrass cultivars listed on the National Turfgrass Evaluation Program (NTEP) at www.ntep.com.

Is Rust Fungus Poisonous to Humans?

No, rust fungus is not poisonous to humans or animals. Eating food with rust on it is discouraged because the flavor is often off.

Life Cycle of Rust Fungus

Rust has a complicated life cycle, but it is important to understand so you know how to interrupt the life cycle and take care of infected plants. Some species of rust go through five stages on two different, unrelated plants. Other species go through fewer life stages and may only infect one plant species.

The optimum conditions for a rust infection are when temperatures are between 68-86F and the foliage is wet. The leaf needs to be wet for 6- 10 hours. A rapid increase in temperature and higher light intensity after that is also conducive to infection. This means plants that are wet all through the night, followed by sunrise and warmer temperatures, create ideal conditions for rust infections. We will be using the Puccinia graminis (Wheat stem rust fungus) as an example of rust disease with all five stages and two hosts.

On Barberry

Stage 0

The basidiospores, made when the overwintering teliospores germinate, infect the barberry plant. They create spermogonia. Each spermogonium has receptive hyphae (female) and spermatia (male). The spermatia have to get to the hyphae to “fertilize” it. The spermogonium produces a sweet nectar substance that flies love. The fly crawls from spermogonium to spermogonium to drink the nectar. She tracks spermatia into hyphae, just like bees track pollen. This is the sexual reproduction stage for the fungus. If this does not happen, the cycle stops.

After the sexual reproduction, aeciospores form and must find a wheat plant to continue the cycle. They are often spread on the wind, then get on the wheat plant when water splashes it up on the leaf.

On Wheat

Stage 1

The aeciospore lands on a wheat plant leaf or stem. If the weather is mild and the leaf is wet, the rust spore germinates. It then goes through the leaf stoma, or pore, into the plant. Once in, mycelium (fungal threads, or hyphae) starts growing and begins feeding on the plant. Spraying the wheat plants at green-up is an effective way to kill the rust spores when they begin to germinate but before they enter the leaf pore.

Stage 2

The mycelium gives rise to uredinia bearing urediniospores. As the urediniospores develop, they burst through the plant’s epidermis, or skin, in the classic rusty-colored spores. These urediniospores can infect nearby wheat plants throughout the spring and summer. They can also reinfect their host plant. This is the most dangerous stage of the plant. Once the urediniospores develop, it is too late to control the fungus until the plant goes dormant in the fall.

Stage 3

In late summer, the uredinia convert to telia which bare teliospores. These are the two-celled, thick-walled black spores that will survive the winter. The rusty brown color on the plant begins to change to black as the switch happens. Once the teliospores develop, wait until leaf drop and spray the host plants with a fungicide. This will kill the fungus before it can spread again.

On Barberry

Stage 4

In the spring, the teliospores germinate into basidia, which make basidiospores. These must infect barberry, not wheat. They are usually transported by the wind. If there are no barberry plants, this type of rust cannot continue growing and dies.

Preventing Rust Fungus

It is very difficult to prevent rust fungus in your garden because it appears in such a wide variety of plants. However, there are some cultural things you can do to lower the chance your plant gets rust.

Buy rust-resistant cultivars

Not all plants that get rust have rust-resistant cultivars. When possible, however, you should buy rust-resistant cultivars. Be sure you look for those in seed catalogs. This information is also on the seed packets of resistant varieties. The little tags in potted plants you get from the nursery should have that information on them, too.

Check plants before bringing them home

Only buy plants from a local and reputable nursery. The plants there will be better quality and less apt to be diseased. Before buying a plant at a nursery, check under the leaves of the plant and around the base of it. If you see any spots on the leaves or stem, don’t buy the plant. Find another plant to purchase. You do not want to introduce rust into your landscape if you can help it.

Quarantine New Plants

Even if you do not see any spots on a plant at the nursery, it is a good idea to quarantine new plants for two weeks before placing them in your landscape. There is a point after infection but before the rust spots burst that is not easily detectable. Quarantining the plants gives the rust time to become evident before it spreads to other plants. Most nurseries guarantee their plants, so if they do show the symptoms of rust during quarantine, take the plants back.

How to water plants to prevent rust fungus?

Rust fungus must sit on a wet leaf for 6-10 hours before it can infect a plant. Do not use overhead watering to water a plant. Water using drip irrigation or other methods that do not wet the plant leaves, only the roots. Soil splashing up on leaves during watering is a major method of infection.

Sometimes you can’t help but use a sprinkler system. If you must water overhead, do so from 5-10 A.M. so the leaves dry before nightfall.

Dispose of infected plants and plant parts properly.

Never compost a plant with any disease or pest problem. The problem will be introduced into your compost. When you spread the compost, you spread the disease throughout your landscape.

Put infected plants and leaves into a plastic bag. Seal it well and put it in the trash. That way, the spores cannot spread to other plants.

Fall Clean-Up

Make sure you clean up leaves and other dead plant parts from your landscape beds each fall. If you have rust-affected plants, cut them to the ground at the end of the season and remove them from your landscape beds. Rust overwinters on leaves and removing them can cut the rust cycle off. Be sure and do not compost the leaves if your plants have had rust. Dispose of them in plastic bags and put those in the trash.

Remove Alternate Host Plants

In the example of wheat stem rust discussed above, farmers who removed barberry plants saw a drop in rust on their wheat the year following the barberry cull. If you have a rust problem and the rust uses two hosts, remove the less desirable of the two hosts to control the rust problem. This doesn’t work if the rust species you have only uses one host.

Hot Water

Because rust can only exist in such a narrow temperature band, hot water kills some types of rust. An example is geranium rust (Puccinia Pelargonii-zones). However, the hot water does some damage to the plant, also.

Wash Tools and Shoes

Rust usually disburses in the wind. However, if you have a plant with rust, make sure you wash your tools and shoes before moving on to the next plant. Spores are tiny and can hitch a ride on your shoes and tools to your other plants. Wash tools in a solution on one part bleach and nine parts water. There are disinfectant solutions you can step in to kill pathogens like rust on your shoes.

How do you treat rust fungus?

If these cultural controls do not keep your plants safe from rust disease, there are some things you can do. Inspect your plants frequently, especially at the base of the leaves near the soil. If you find symptoms of rust, you can remove the leaf that it appears on. Don’t remove more than 1/3 of the leaves at one time. Once you find rust in a vulnerable species, you will need to treat it to save that plant and others of the same species in your landscape.

Chemical treatments

Chemical fungicides should be used in early spring right when new growth appears on the plant or in the fall after leaf drop. Fungicides are not effective after rust symptoms appear. Chemical fungicides have to be repeated every 4-5 weeks while the temperature and moisture are conducive to the fungus. After the weather warms up, rust cannot reproduce even if it is present in the plant, so you can stop the treatments.

Before using a fungicide, be sure the label mentions the name of your plant or family of plants on it. Obey all the directions and warnings on the label. Remember, the label is the law. Wear long sleeves, long pants, and closed-toe shoes to use any chemical, including organic ones. Be sure to change clothes after you use the fungicide so you don’t track it into the house.

Fungicides can be expensive, so determine the value of the plants you want to protect. A very low level of rust in a full landscape can probably be controlled by removing infected leaves without having to use fungicides. If the plant is a high value plant, then it may be worth it to administer a fungicide. The same is true if the alternate host to a rust infecting a high value plant cannot be removed.

There are many different synthetic antifungals around. Your Extension agent can recommend some if you want to take that route. If you want to use an organic anti-fungal, you have two choices.

Copper Fungicides

Copper fungicides can provide control of some rust fungus, depending on the species of rust. Rust fungus has evolved to display resistance to some fungicides, so contact your Extension agent to find out if the rust you have is susceptible to copper.

Sulfur Fungicides

Sulfur fungicides provide control of rust fungus. As with copper, some rusts may be resistant to this fungicide. Do not apply sulfur after the temperature has warmed up as it will damage the plant.

So many different plants are susceptible to rust fungus that most gardeners will see at least one case of these fungal plant diseases. There are many things you can do to protect your plants from rust fungal diseases. When you find rust, remove the infected plant parts, if possible, and dispose of them carefully. Treatments for rust must be used at green-up in the spring or at leaf drop in the fall. By the time symptoms appear, it is too late.

Treatment

  1. Select rust-resistant plant varieties when available.
  2. Pick off and destroy infected leaves and frequently rake under plants to remove all fallen debris.
  3. Water in the early morning hours — avoiding overhead sprinklers — to give plants time to dry out during the day. Drip irrigation and soaker hoses can be used to help keep leaves dry.
  4. Use a slow-release, organic fertilizer on crops and avoid excess nitrogen.  Soft, leafy, new growth is most susceptible.
  5. Apply copper sprays or sulfur powders to prevent infection of susceptible plants. For best results, apply early or at first sign of disease. Spray all plant parts thoroughly and repeat every 7-10 days up to the day of harvest.
  6. Effectively treat fungal diseases with SERENADE Garden. This broad spectrum bio-fungicide uses a patented strain of Bacillus subtilis and is approved for organic gardening. Best of all, it’s safe to use — you can treat and pick crops the same day!
  7. Containing sulfur and pyrethrins, Bonide® Orchard Spray is a safe, one-hit concentrate for insect attacks and fungal problems. For best results, apply as a protective spray (2.5 oz/ gallon) early in the season. If disease, insects or wet weather are present, mix 5 oz in one gallon of water. Thoroughly spray all parts of the plant, especially new shoots.
  8. Prune or stake plants and remove weeds to improve air circulation. Make sure to disinfect your pruning tools (one part bleach to 4 parts water) after each cut.
  9. Use a thick layer of mulch or organic compost to cover the soil after you have raked and cleaned it well. Mulch will prevent the disease spores from splashing back up onto the leaves.
  10. Burn or bag infected plants after the growing season (see Fall Garden Cleanup). Do NOT compost.

Recommended Products

Rust on fruit trees and shrubs. Control measures and prevention against plant rust. Photo - Botanichka

A summer cottage is usually divided into several sectors: residential with outbuildings, a garden where favorite vegetables are grown, flower beds and a recreation area that includes herbs, flower beds, ornamental shrubs, including conifers. An obligatory part of the cottage is a garden and a berry garden, and in it are your favorite pears, apple trees, cherries, plums, cherries, quince of different ripening periods. Berry is rich in several varieties of raspberries, currants, gooseberries, shadberry, sea buckthorn. Beautiful garden and berry plot during the flowering period. But there comes a period, and the blossoming leaves are covered with small yellow-brown dots, which gradually grow into large spots. Rusty-yellow spots with fiery eyes cover the upper side of the leaves of apple, pear, plum, gooseberry, currant. It becomes clear that these are not mechanical damage or treatment of plants with the wrong drug (for example: a herbicide instead of a drug for diseases), but a real disease. Trees and shrubs are affected by "vegetative" or "biological" rust.

Currant leaf rust caused by the fungus Cronartium ribicola. © Marek Argent

Contents:

  • Rust pathogen and life cycle
  • Measures to protect plants from damage by rust fungi
  • Rules for the treatment of plants with chemicals against rust fungi
  • Anti-rust chemical treatment plans
  • Protection of soda and berry plantations from rust with biological products

The causative agent of rust disease and its development cycle

The causative agent of the disease is Rust fungus , which parasitizes higher plants of many families. Infection of plants begins in April in the form of brown-black dots on the upper side of the leaf blade of the affected plants. Each dot is a local infection caused by one or two spores of the fungus.

Spores are carried by wind and insect pests (ants, aphids), causing multiple damage to the leaves of fruit plants. The dispersal of mature spores by the wind can provoke a massive infection of horticultural crops of the same species over long distances.

Once in the host plant, the spores germinate and the mycelium spreads within the tissues throughout the culture. Rust-yellow spots on the leaves of trees and shrubs affected by the disease are an external manifestation of a fungal disease that is collectively called rust. In the summer, outgrowths appear on the underside of the leaves of diseased plants in the form of threads on apple trees or nipples on pears. It formed disputes, ready to defeat the hosts.

The group of rust fungi is distinguished by the ability to form different types of spores in the development cycle. These spores can go through the entire development cycle on the same or on different plants. According to these features, they are divided into 2 groups:

  • single house,
  • heterodomestic.

Monoecious rust fungi re-infect the host and other plants of the same species: apple tree, other types and varieties of apple trees; pear, other varieties of pears, etc.

A group of heterodomous rust fungi usually develops on two different plants, but ends its development cycle, as a rule, on fruit crops.

  • For apple trees affected by heterodomous rust fungi, the main host of the fungus is common juniper;
  • for pears - Cossack juniper;
  • for plum - anemone weed.

Pine, spruce and other conifers are severely affected by rust.

Of the berry bushes, currants, gooseberries, and raspberries are strongly affected by rust. Their intermediate hosts are sedge, Weymouth pine. Cedar pine - intermediate host of black currant

By spring, outgrowths (pustules) appear on the intermediate host, in which mature spores (basidiospores) are located. When they break, yellow dust or "rusty powder" is poured out. These are mature spores that scatter under gusts of wind up to 60-100 meters and infect leaves, young shoots and fruits of fruit crops.

Fruit crops are an intermediate host of rust. Sick leaves of fruit berries and horticultural crops dry out, curl up. Early leaf fall begins. Plants are deteriorating. The yield and quality of fruits are sharply reduced. If protective measures are not taken, the affected trees and shrubs will die.

Rusty fungus Currant Kronartium on Weymouth Pine. © Marek Argent

Measures to protect plants from damage by rust fungi

To protect garden and berry plantings from rust, a set of measures and their constant implementation are necessary. Protection will not bring effect with a single treatment, especially from heterogeneous fungal diseases.

Protective measures can be divided into several groups:

  • preventive;
  • agricultural;
  • chemical;
  • biological.

Preventive measures against damage by rust fungi

  • Systematic examination of horticultural crops to diagnose diseases.
  • Keeping the site in a condition free from weeds, especially from sedge, anemone, milkweed, which are intermediate hosts of the disease.
  • Cleaning the garden from leaf fall. Sick leaves are best burned outside the site.
  • Cleaning from the site of plants that serve as the main host of pathogenic fungi, or carrying out simultaneous treatment of both plant species (junipers, conifers).
  • Only zoned and resistant to rust varieties and hybrids of fruit and berry crops should be used for the orchard and berry plot.

Agrotechnical measures against damage by rust fungi

Observe the agricultural practices recommended for the crop, especially in terms of watering. Do not allow stagnation of irrigation water under trees and shrubs. In a humid environment, fungi multiply especially quickly. Be sure to monitor the onset of the disease during prolonged (7-10 days) wet weather.

Annually, in spring and autumn, it is necessary to whitewash the trunk and skeletal branches of horticultural crops with a solution of freshly slaked lime with the addition of clay and glue (for better adhesion), copper-containing preparations (copper sulfate, cineb, cuproxate).

Sanitary pruning is carried out after complete leaf fall or in spring before bud break. Remove all branches and bark with signs of disease (covered with tubercles or orange growths), capturing 10-15 cm of a healthy place. Branches freed from diseased bark, treated with copper or iron sulphate, covered with garden pitch.

Dig up near-stem circles in autumn or spring and treat the soil surface with a 5-7% solution of urea or ammonium nitrate, alternating with a 4-5% solution of copper sulphate.

Be sure to treat tree crowns with antifungal agents. In the spring, additionally arrange a shower of microelements with substances that help strengthen immunity to diseases.

Destroy juniper, other coniferous and non-fruit plants, herbs suffering from rust on the site. Treat their location several times with boiling water or blue vitriol, Bordeaux liquid or other anti-rust preparations.

Rust spots on leaves. © Jose Maria Escolano

Rules for the treatment of plants with chemical preparations against rust fungi

It is not recommended to use chemical preparations to combat crop diseases in private areas. If preference is given to chemical preparations, then the working solution for spraying must be prepared strictly in accordance with the recommendations. Of the drugs, give preference to pesticides of systemic, systemic-contact and contact action.

Take all sanitary protection measures (high shoes, closed clothes, headgear, goggles, respirator, gloves). At the end of the treatment of plants, change clothes and take a shower.

Treat plants in the morning after the dew has disappeared before 11 am or after 4-5 pm in dry, calm weather.

Drain pesticide residues into a special pit or a place inaccessible to children, animals, birds.

End pesticide treatments 30-35 days before harvest (unless advised otherwise) and never treat plants during flowering.

To reduce the load on plants, it is better to spray with tank mixtures, combining several drugs against diseases and pests in one solution. Before mixing, pre-check the preparations for compatibility.

Anti-rust chemical treatment schemes

Several schemes for the treatment of plants affected by rust can be suggested (as examples). They are easy to prepare, but require strict adherence to recommendations.

Experienced gardeners (no doubt) have other tank mix formulations in their arsenal, but in any case, the use of chemicals requires attention and processing during certain periods (phases) of plant development. Usually, all treatments are carried out before and after flowering, so as not to kill beneficial insects (bees, bumblebees, predatory insects - ground beetles, ladybugs).

1. Before bud break, treat trees with 2-3% solution of Bordeaux mixture. Repeat treatment with 1% solution during budding and after flowering. The last treatment is carried out at the beginning of the growth of the fruit.

2. In the same phases, treat the first time with 1% copper sulphate (blue spray), the second with copper oxychloride, or ordan, oxychome. You can use the drug Abiga-Peak. The third spraying is carried out with kuprosil or 1% Bordeaux liquid. Some gardeners recommend spraying with 1% Bordeaux liquid again after 10-12 days.

3. The chemical fungicide topaz is effective against rust. Three times treatment is enough to protect against rust. Treatments begin in the phase of bud break, immediately after flowering and in the phase of fruit growth.

4. Carry out the first and second treatments with 1% solution of Bordeaux mixture. It can be replaced with Kuprosil preparations, champion. The third treatment is carried out with colloidal sulfur or thiovit. For the fourth treatment, you can use the drug "propy plus", any other drug that acts on several types of fungal diseases.

Rust on goat willow leaves. © dejayM Rust on goat willow leaves. © dejayM General view of the rusty bush. © dejayM

If it is undesirable to remove the primary source of infection (juniper, other conifers), then both types of plants are treated simultaneously. For the destruction of fungi on the main sources of rust infection, the following treatment schemes can be recommended. Please note: when processing junipers, conifers, weeds, at the same time continue processing fruit and berry plantings with recommended preparations.

If the bushes are healthy, then as a preventive measure they are treated 2-3 times during the warm period with the following preparations: fast, bayleton, cineb, Bordeaux mixture. It is recommended to treat plants in early spring and late autumn with cuproxate.

Other copper-containing preparations can be used, and plants can be sprayed up to 6 times during the growing season (they are not used for food), with mandatory processing in late autumn and early spring. Special preparations saprol and ditan were produced. Spraying with these preparations is carried out alternately with an interval of 7-8 days.

To increase the resistance of junipers and other conifers to rust and other fungal diseases, it is advisable to treat plants with microfertilizers and immunostimulants.

A special preparation saprol (triforin) has been proposed for the treatment of juniper. Spraying begins in early spring and continues throughout the warm period with a gap of 7-10 days.

It is necessary to systematically inspect and remove diseased shoots. If the bush is badly damaged, it can be cut off completely, leaving 1-2 live buds at the base. Dig up the soil around the cut bush. Apply full fertilizer for digging with nitroammophoska, preferably Kemiru. In late autumn or spring, treat the soil with urea or ammonium nitrate (5-7% solution), mulch. It is more expedient to transplant a cut bush to another place, at a greater distance from fruit and berry plantations.

Protection of soda and berry plantations from rust with biological preparations

In order to obtain an environmentally friendly harvest in summer cottages, it is necessary to use biological preparations for protection. They are developed on the basis of effective microorganisms and do not harm the health of humans, animals and beneficial insects. Biological products are not toxic, do not accumulate in fruits and other parts of plants. The protective effect of biological products is about 3 weeks. They can process plants until harvest.

They are easily mixed with other biologicals in tank mixes, which reduces the number of treatments for various pests and diseases. However, their effective action is manifested only in a certain range of positive temperatures (from +12 to +18 ° C) and exact proportions are observed in the manufacture of working solutions. If the requirements are not met or only 1-2-3 treatments are carried out, the effect will not appear.

A gardener's first aid kit must have a set of biological preparations for processing vegetables, horticultural and berry crops. To protect plants from rust, trichodermin, planriz, phytosporin-M, gamair (bactericide), phytodoctor, gaupsin are used. The last drug stands out for its dual action. It not only destroys fungal diseases, but also a number of pests.

Juniper blister rust (Gymnosporangium juniperinum). © SB_Johnny

Preparation of working solutions of biological products

Trichodermin

To destroy rust and other fungal diseases, prepare a working solution at the rate of 100 ml of a biological product per 10 liters of water. Spraying begins with the phase of bud break and continues throughout the growing season (except for the flowering period) 2-3 times a month.

Planriz

Effectively protects garden plants from many fungal diseases, including leaf rust. It has a strong growth-stimulating effect on plants. For spraying, use a working solution of 50 ml of planriz per 10 liters of water.

Phytodoctor

It is equal to planriz in the list of effective suppression of pathogenic fungi. The consumption rate of the biological product per 10 liters of water is 30 g. Spraying is carried out throughout the growing season 2 times a month. Phytodoctor increases immunity to diseases and promotes the active development of fruit and berry crops.

Fitosporin-M

For spraying plants during the growing season, a working solution is used, consisting of 15 ml of a biological product per 10 liters of water. The same solution can be used to process fruits during storage.

For plant treatment, along with working solutions of individual biological products, tank mixtures can be used in the following composition: dissolve 100 ml of trichodermin and gaupsin biological products, 50 ml of planriz and ecoberin in 10 l of water, add 30 g of phytodoctor. Before mixing, check preparations for compatibility. Spray trees and shrubs (all) every 10 days throughout the growing season.

The article contains only a few biological products. Having studied the effect of other biological products, you can independently select tank mixtures and grow healthy, environmentally friendly crops painlessly for the environment and family members.

causes and signs of appearance, how to get rid of

Rust on trees is a common fungal disease that affects trees and shrubs, both deciduous and coniferous. It is dangerous for both ornamental and fruit crops: the former begin to look unattractive, the latter reduce productivity, and in the future the plant may even die. The manifestations of the disease may look different, but the main symptom is the reason for the appearance of the name “rust”: when a plant is damaged, pustules (tears) of bright orange, brown or rusty color appear on it.

How rust manifests itself and why it is dangerous

The disease manifests itself in plants and seriously reduces their immunity, as a result, they become more susceptible to cold and environmental influences. Initially, the fungus infects the shoots, then it moves to the leaves. Rust can quickly destroy a plant, but even if this does not happen, without treatment, a tree or shrub will die over time: reduced immunity will not allow it to survive frosty weather. The disease is contagious: an affected plant is capable of infecting others. The fungus is transmitted on the paws of insects and birds that have come into contact with the diseased tree, sometimes even downwind. So when rust is first detected, action must be taken, otherwise the entire garden may soon be infected. There are single-farm and diversified subspecies:

  • the former are able to parasitize only one type of plant, for example an apple tree;
  • the latter are more dangerous as they can infect trees, flowers or shrubs of different species.

How to recognize. Usually this is not difficult: characteristic rusty growths appear on the lower surface of the leaves, which increase and merge into one. The growths, which are also called pustules, are dry to the touch, crumble when damaged: inside they contain spores of the fungus, which causes the disease. The contents of the pustules can infect other plants.

How develops. Initially, the fungus, falling on the plant, affects the shoots, but quickly passes to the leaves. At this stage, a characteristic symptom appears: spots and growths of a red, brown, less often pink hue. The spots gradually increase, completely cover the leaf, the pustules eventually crack, break and release spores - as a result, the disease spreads rapidly. Due to damage to the leaves, the metabolism inside the plant suffers:

  • moisture exchange is disturbed, the tree or bush begins to suffer from dehydration;
  • failures in the process of photosynthesis begin;
  • growth stops, damaged leaves and shoots die off and fall off, new ones stop appearing.

Timely treatment is necessary: ​​without it, the plant can easily die.

Methods for protecting plants from rust

To combat the disease, a set of protective measures is needed, which should be carried out regularly. A single planting treatment will not give the desired effect, especially if the rust pathogen has two host plants.

Preventive measures . They are not so much a way to protect, but to reduce the risk of rust. The standard list of such events includes:

  • regular weeding of the area from weeds, especially those plants that belong to the hosts of the fungus;
  • constant monitoring of the condition of garden trees and shrubs for early detection of the disease;
  • carrying out simultaneous processing of fruit and coniferous crops, if the removal of the latter from the site is impossible or undesirable;
  • mandatory autumn cleaning of fallen leaves, providing for their removal and destruction (burning) outside the site;
  • use only special horticultural crops with a high degree of rust resistance.

Agrotechnical measures . Their implementation is aimed at creating unfavorable conditions for the development of rust. The standard list of agrotechnical measures includes:

  • Strict adherence to watering requirements. It is unacceptable for water falling under trees and shrubs to stagnate, as high humidity creates favorable conditions for the development of fungi of all kinds;
  • annual whitewashing of stems and skeletal branches . Whitewashing should be carried out both in spring and autumn;
  • sanitary trim . It is carried out in the fall after the leaves have completely fallen off or in the spring before bud break. All diseased branches should be cut, capturing 10–15 cm of healthy length. After removing the affected bark, it is necessary to apply garden pitch or other means of protection to the surface;
  • Digging up the tree trunks . It is carried out in spring or autumn.

An integrated approach and the use of several methods at once can reduce the likelihood of infection and prevent the rust disease from hitting the garden.

"Rakurs" for treatment and prevention

The manufacturer "August" offers a powerful remedy for getting rid of the disease - "Foreshortening". It can be used for prophylactic purposes or if the disease has already manifested itself on the plant: the two-component composition includes substances with different rates of action and penetration into tissues. Therefore, the tool can be used at different stages of the disease.

  • "Rakurs" quickly penetrates into plant tissues and is not afraid of rain within 2 hours after application. It has strong systemic characteristics and spreads easily throughout the plant up to the top.
  • In addition to rust, the product fights other diseases: powdery mildew, spotting. This is a complex drug that protects against several threats at once.
  • Due to the peculiarities of the composition, the agent seems to stick to the leaves and does not lag behind them, therefore it can affect the disease for a long time.
  • The drug has a prolonged effect - up to 3 weeks of successful protection.

How to use Racurs

The product is sold in the form of a concentrate, which is diluted with water in a ratio of 4 ml per 5 liters.


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