Yellow spots on pear leaves: why and what to do

If the foliage on pear trees turns red and begins to fall off prematurely, and “horns” appear on the back of the leaves, it means the tree is seriously ill. We will tell you how to treat a pear from rust.

The causative agent of pear rust is the pathogenic fungus Gymnosporangium sabinae. Its peculiarity is that for development it requires at least two host plants: for example, juniper and pear. However, the main ones are the different types of juniper (Cossack, tall and many others popular in ornamental gardening). It is on them that the pathogen overwinters and subsequently moves to the pear. Maximum damage (up to 50-100% of the harvest) is observed in the Black Sea region (southern regions of Ukraine and Russia). Up to 15-30% of crop losses occur in Georgia, Krasnodar and Stavropol territories.

Why do pear leaves become covered with yellow spots?

During the growing season, the standard foliage color varies from green to dark green. The appearance of extraneous stripes or spotting indicates preliminary preparation of trees for the winter season or health problems.

Rust on the pear

Frequent sources of anomalies include insufficient supply of nutrients or damage to the crop by pathogenic microorganisms that provoke the formation of “rust”. In the first option, the gardener must check the amount of fertilizer applied and the presence of nitrogen, iron, zinc and manganese in them; in the second, carry out therapeutic procedures to destroy the source of pathology.

To clarify the preliminary diagnosis, it is necessary to take into account the symptoms:

• Lack of iron - manifests itself as a whitish color of foliage with yellowness at the edges. With a partial deficiency of the element, the veins on the leaves remain green, without a visible change in the main color.
• Manganese deficiency is determined by yellow-green dots scattered on the surface of the leaf blades.
• Insufficient supply of zinc provokes thinning of the foliage and a decrease in size. In some cases, yellowness forms at the ends of young shoots.

Orange spots on a pear can occur due to a fungal infection. An extraneous bright orange color appears in summer days or early autumn, the affected areas feel sticky to the touch. Ripe spores quickly migrate through other garden plants with the help of insects, infecting healthy crops.

The appearance of non-standard shades of sheets in spring is a symptom of the development of scab. Over time, the foliage acquires brownish or olive tones in areas of infection. The disease spreads only in high humidity.

Important! Gardeners recommend promptly removing fallen leaves, preventing the development of fungal pathologies in cultivated varieties.

Sources of the problem

Resistant and unstable varieties

Pear diseases: description of diseases, how to treat brown spots on leaves

Breeders have developed certain varieties of pears that are resistant to rust. The list is presented:

• Gordzaloy;
• Gulabi;
• Sailo;
• Sugar;
• Suniani;
• Chizhovskaya, etc.

Important! Crops susceptible to rust include Klapp's Lyubimitsa, Winter Dikanka, Curet, Boek, Bere, etc. Seedlings require regular preventive treatment.

Variety Chizhovskaya

Bacterial infections

Bacteria, like fungi, are dangerous to all garden crops. They are present in the form of single-celled microorganisms lacking chlorophyll and obtain their nutrition from infected cultures.

The pathogen penetrates through various mechanical damage on leaf blades and trunks. To avoid infection, existing garden tools must be carefully processed. Plants are provided with proper care, because strong and robust crops are not susceptible to diseases.

Cortex cancer

Bacterial necrosis of pear bark appears in early spring. Browning of the buds and bark can be seen, young shoots dry out and turn black. The causative agent of the disease is Erwinia amylovora.

The spots on the leaves are black. Feature: cracking along the edges. Blisters appear on the bark, depressed spots with a cherry-purple frame are formed. The tree quickly rots, emits an unpleasant odor, and then dies.

The treatment is complex and consists of large-scale pruning of the tree and three-time treatment, for which azophos and copper sulfate are used. This technique helps prevent the further spread of the disease, and sometimes helps eliminate it. In advanced cases, the fight is useless; the tree must be removed.

Attention! If the main purpose of pruning is to treat cancer, the cut is made to include healthy tissue (at least 10 cm).

Root cancer

As a result of bacterial activity, small, barely noticeable soft spots form on roots and above-ground growths. Then they grow and harden. Their surface is initially smooth, then becomes bumpy due to the formation of secondary growths. By autumn, the roots rot and collapse, appearing the next year.

The provoking microorganism lives in the soil for up to 2 years, even without a host plant. The parasite penetrates the culture tissue through mechanical damage. Damage to young seedlings in nurseries is more common.

Bacterial burn

The first symptoms of the disease are noticeable in spring on the branches of a young plant. Kidney growth and development slows down. If there are blossoming leaves on a tree, they turn black and dry out, but remain on the tree and do not fall off. When pears are damaged at the stage of fruit formation, they also turn black and dry out, right on the branches. The same thing happens with flowers and buds.

Damage to the trunk is dangerous; it will not be possible to save the pear. The only rational solution is to remove the tree from the site.

To treat this disease, the antibacterial drug Streptomycin is used. The plant is treated with the product during the growing season. Compositions that can increase the immunity of the crop are used together.

Consequences of inaction when leaves on a pear turn yellow

The danger of orange spots on pear leaves is determined by the sources of their occurrence. If seasonal changes are not the cause, plants and crops can be seriously damaged by a gradually spreading infection.

There are spots on the leaves on the orchid - what to do?

The capture of pear by rust leads to disturbances in the processes of photosynthesis in the foliage and a rapid weakening of the crop. The fruits will become tasteless and small, and with a prolonged illness, over several years, the wood will begin to be damaged and become covered with corresponding growths.

Loss of leaves leads to depletion of the crop, weakened immunity and vulnerability to pests and diseases. The frost resistance indicator decreases, even in the middle zone there is a possibility of shoots being damaged by frost.

A crop that has been ill stops bearing fruit or produces a minimal harvest with small and tasteless fruits. To reduce the risk of infection, gardeners prefer to plant rust-resistant varieties in their garden plots and check the adequacy of the supply of nutrients.

Important! The risk of the disease increases in the garden where Cossack juniper is grown. The plant is one of the main sources of fungal infection of pears and apple trees.

Rust on juniper

Causes of orange spots on leaves

The disease got its name due to the characteristic orange-rusty color that appears on the leaves of fruit trees.

The disease can cause the death or infertility of a pear tree.

The fungus uses juniper and its ornamental varieties to form spores, which subsequently infect the pear. At the same time, the pear tree is only an intermediate link in the development of the pathogenic fungus, which after the required time returns to the juniper.

Disease Catalyst

Wet, windy weather promotes the development and spread of fungal spores.

First, fungal spores appear on the juniper.

How does the disease develop and spread through a tree?

Gymnosporangium sabinae is a parasite with a two-year cycle, changing between two “hosts”. The first is the Cossack juniper, the second is the pear. The damage to crops is noticeable from the end of April - small round spots with a yellowish-greenish tint form on the leaves. They do not exceed 0.5 mm in diameter.

Anthurium has brown spots on the leaves - causes and treatment

As they spread, they cover the entire surface of the damaged leaf plate and swell. In the affected areas, on the outside of the foliage, spermogonia develop. Aeciospores with a finely warty surface are formed in the lower part. On windy days or on the legs of insects, they move around the area, and when exposed to a humid environment, they germinate on healthy leaves and form mycelium.

The mycelium eventually spreads throughout the tissues, promoting cellular growth and thickening of the affected surfaces. 2-3 years after infection, teliospores form in the form of cone-shaped horn-like outgrowths on the branches and trunk of the pear. They transform into basidia, quickly covering the entire surface of the plant with the arrival of spring, moving into the parenchyma and re-forming the mycelium.

Important! The fungal infection overwinters on infected juniper, and in the spring months it moves to the foliage of pears.

Growths on leaves

What to do if the leaves on a pear turn yellow

Combating abnormal green color requires finding the source of the problem. If there is a significant lack of nutrients, it is enough to fertilize with complex mineral fertilizer. In other cases, the solution is more complicated; the gardener will have to mechanically clean the affected crop, use fungicidal preparations, etc.

Treatment with chemicals

The use of industrial solutions is considered the most successful solution in the fight against rust. For therapy, drugs containing copper are used:

• 1% solution of Bordeaux mixture;
• "Champion";
• "Kuproksat";
• "Cuproxyla".

You can deal with the problem:

• "Fundazol";
• "Topsin M";
• "Byleton";
• "Cumulus DF";
• "Tiovitom Jet" etc.

Treatment procedures follow a specific algorithm:

1. Primary treatment is carried out before the buds swell, in early spring.
2. Secondary - after flowering is completed, fungicides are applied.
3. The final stage is for fruits the size of walnuts. Spraying of solutions is carried out 2 weeks after the second manipulation.

To completely destroy pathogenic microflora, it is necessary to treat plants four or more times per season. The procedures are repeated annually for 2-3 years. The problem can only be solved with an approach that will prevent crop loss and normalize harvest volumes.

Important! Beginners should not forget that using the same drugs can cause the pathogen to become addicted to the active substances. It is necessary to alternate remedies without repetitions, otherwise you can treat the pear endlessly.

Processing scheme

Mechanical fight

A physical solution to the problem involves the timely removal of infected foliage, before the buds open. Damaged branches are cut 10 cm below the areas infected with the fungus. Wound black surfaces on shoots are cleaned to healthy tissue and washed with a 5% solution of copper sulfate.

The healing process is accelerated by treating the damaged areas with a Heteroauxin solution (in a proportion of 0.5 g per bucket of water) and covering them with Garden Var. Excised branches and foliage are burned - specimens left on the site can become a source of secondary infection and will help the crop to become covered with rusty spots again.

Traditional methods

Many gardeners have a negative attitude towards industrial means for combating diseases of pear specimens. They prefer to use homemade solutions; the list of basic products includes:

• Wood ash infusion - 0.5 kg of the substance is diluted in 10 liters of liquid and sent to a darkened room for 2 days. The finished mixture is poured into a spray bottle and the affected specimens are treated.
• Manure infusion - the product is diluted with water in a ratio of 1 to 2 and aged for one week. The prepared product is diluted a second time by 50% and the diseased crop is watered. Each adult plant requires at least 10 liters of infusion, young plants - from 4 to 6 liters.
• Soap and soda solution - 5 tbsp. l. Linen soda is mixed with 50 grams of pre-grated laundry soap and diluted in a bucket of water. After half an hour, the garden is sprayed; it is best to apply the composition after the flowering phase has completed.
• Flower infusion - 0.5 buckets of recently picked marigolds are poured with the same amount of warm liquid. The mixture is infused for 48 hours, filtered and mixed with 50 grams of crushed laundry soap. After flowering is completed, diseased crops are treated with the solution.

Important! Experts do not trust alternative methods of treating fungal diseases. Home remedies can counteract them only in the initial stages of pathology development.

In case of massive rust or scab on pears, you need to use professional store-bought preparations. Solutions are prepared exactly according to the manufacturer's instructions.

Treatment options

What preparations should be used to spray a pear against rust?

To treat pear trees affected by rust, it is recommended to use fungicides, the main components of which are copper and sulfur. Let's look at the 5 most effective drugs:

The drug "Polychom" brand "Iskra"

Protective contact fungicide, a chemical mixture of 60% metiram and 20% copper oxychloride. Release form: suspension 0.4%. An effective drug in the fight against rust, scab, moniliosis, white spot, black cancer. The frequency of processing is no more than 5 times.

• Advantages: Non-toxic to beneficial insects and birds. A safe preparation for plants, has a beneficial effect on plants, increases productivity.
• Disadvantages: It is prohibited to use in the sanitary zone around fishery reservoirs.

Bordeaux liquid of the Green Belt brand

Broad-spectrum fungicide. The active ingredient is copper sulfate. Release form: water-soluble powder. It is used to combat rust, scab, moniliosis, spotting. The frequency of processing is no more than 6 times.

• Advantages: Not dangerous for beneficial insects, birds and plants. Compatible with pesticides.
• Disadvantages: Incompatible with the vast majority of fungicides, especially those that are destroyed in an alkaline environment.

The drug "Baleiton" brand "Green Belt"

Systemic fungicide to combat mainly rust and powdery mildew on fruit trees. Active ingredients: triadimefon, copper sulfate. Release form: powder. The frequency of processing is no more than 2 times.

• Advantages: Not dangerous for beneficial insects. A safe preparation for plants, has a beneficial effect on plants. High compatibility with other drugs. Not washed away by precipitation.
• Disadvantages: It is prohibited to use in the sanitary zone around fishery reservoirs. Moderately toxic to warm-blooded animals. Causes resistance, requires a change in drug.

The drug "Strobi" brand "BASF"

A new generation fungicide, the active ingredient is strobilurin A. Designed to protect fruit trees from diseases such as rust, powdery mildew, and late blight. Release form: water-soluble granules. The frequency of processing is no more than 3 times.

The drug "Strobi" brand "BASF"

Advantages: not dangerous for beneficial insects and warm-blooded animals. It is compatible with a huge number of drugs. Not phytotoxic. One of the rare drugs that can be used during the flowering period of fruit-bearing trees. Not addictive. Not washed away by precipitation.

The drug "Raek" brand "August"

Systemic fungicide, active ingredients difenoconazole, copper sulfate. Designed to combat rust, scab, powdery mildew, and late blight. Release form: emulsion. The frequency of processing is no more than 4 times.

• Advantages: Not dangerous for beneficial insects. Not phytotoxic. High compatibility with other drugs. Not washed away by precipitation.
• Disadvantages: It is prohibited to use in the sanitary zone around fishery reservoirs. Moderately toxic to warm-blooded animals.

The table shows the effectiveness indicators of the above drugs, as well as the consumption of drugs and the optimal timing of their use.

Bordeaux liquid for treating pears against rust
Ready-made solutions must be applied using a fine spray method, which will allow most of the preparation to remain on the leaves of the trees. A fine spray prevents the drug from draining from above-ground organs and promotes rapid absorption of the solution.

Preventing problems

Preventing the development of pathologies will help avoid damage to the entire garden. Gardeners recommend not planting juniper next to the crop and regularly inspecting the plants for rust symptoms. Why the infection cannot appear again: timely removal of affected branches and foliage will prevent mass infection.

Chemical control

After the leaves fall in the fall, garden owners should sanitize pruning pears, spray them with fungicides and prepare them for the next season. With the onset of spring days, therapy continues and is carried out in three steps:

• before buds open;
• before the buds open;
• after the end of the flowering period.

Preventive spraying is carried out with 1% Bordeaux mixture or any copper-containing preparation at least 3 times per season. If the pear is not resistant to scab, it is treated regularly, but in this case additional prevention against rust is not used.

Important! If Caucasian juniper grows next to pears, then it also needs to be constantly inspected.

Bordeaux mixture

Non-chemical control

It is better to plant ornamental plants in a personal plot away from pears and other trees. In this case, the risk of mutual infection is reduced. Planned preventive measures include the following recommendations:

• regular inspections of rose bushes, juniper and cultivated plants - for timely identification of foci of developing disease;
• destruction of weeds near cultivated plants;
• remove fallen leaves from the root system and remove them immediately outside the site;
• whitewash the trunks and skeletal branches with a mixture of lime and copper sulfate;
• add suitable nutrients in the fall - potassium chloride, superphosphate;
• treat the tree trunk circle with a 7% urea solution - upon completion of collecting foliage.

Most novice gardeners make a serious mistake when trying to plant conifers and other crops in close proximity.

In order to prevent rust from appearing in the area, it is important to observe certain conditions: protect the pear from proximity to juniper or other coniferous plants, regularly prune and fertilize, and treat it with fungicides in a timely manner for preventive purposes. Proper care and timely protection will help avoid fungal infections. Treatment of rust takes several years and it is difficult to cope with the pathology; it is easier to carry out preventive measures.

Yellowness on the foliage may be a sign of disease or improper care of the pears. Before starting rescue work, the gardener must make sure that the change in the color of the greenery is not associated with a deficiency of nutrients.