In Iran, Armillaria disease has been observed on the roots of pear trees in the cities of Isfahan, Tehran, Tabriz and Shandiz Razavi Khorasan. No significant damage was reported. The cause of this fungal disease is called Armillaria mellea. This fungus is earthy and can survive long in the soil. The method of Armillaris rot of trees agent transmission is through the roots inside the soil. When the roots touch each other, the pathogenic fungus is transferred from the diseased roots to the healthy roots. This method is for adjacent trees. Alternatively, the pathogen enters the garden through irrigation, entry of infected seedlings and soil.
Category: Tree Diseases
Rosellinia rot of pear trees
The spread of root Rosellinia rot disease in Iran is high, but it does not cause significant damage as only one or two trees with each disease may be reported from each garden. The provinces in which the disease has been reported include Isfahan, Karaj, Qazvin and Tehran. The causative agent of Rosellinia nectarix pear disease is called Rosellinia nectarix. Its sexual form is Dematophora nectarix. This fungus produces Prietz and Cinema, which are rarely found in nature. to control this disease use biological fungicides like Trichodermaroot.
Pears brown rot
The disease, also called pear mummy, is not common in pear orchards in Iran. Specimens of pests infected with this pathogen were found in Guilan province and Noshahr province and after investigation, Molinia frutigena was identified. The sexual form of this fungus called Monilinia fructigena has not been found on pears in Iran. The disease is similar to moniliac or brown rot of apples.
Pomegranate fruit rot due to Alternaria
In most pomegranate orchards, pomegranate fruit rot alternaria is common. However, at the end of the season the disease is present on tree fruits. The disease is much more severe in Anbar and cold storage.
Symptoms of Pomegranate Rot Disease: The growth of the fungus within the fruit is very rapid as the flesh softens and crushes the fruit, turning the shades of black to gray. If the pathogen is entered through the holes created in the fruit’s throat, the disease will have no symptoms, but the symptoms appear when the pathogen enters the fruit through wounds and tissue damage. In infected and diseased fruits, soft, crushed tissue can be clearly seen in the affected area. Pomegranate fruit rot takes on a lighter color and is torn.
The cause of the disease can be various fungi, including Alternaria.
Important factors in pomegranate root rot are:
۱٫ Environmental factors that cause fruit cracks or thorns in the branches to hit and injure the fruit in the wind.
۲٫ Insects that infiltrate either themselves or larvae into the fruit can carry pomegranate fruit rot into the fruit. Like the pomegranate throat worm with the scientific name Spectrobata ceratoniae.
۳٫ Sucking insects as they age. They do not enter the fruit, but they insert their bite or onion, which may be contaminated with the fungus, so they carry the fungus into the fruit.
۴- Damage caused by mites, sunshine and mechanical factors.
۹۰% of the actions that can be taken against pomegranate fruit rot due to alternaria are related to the control and control of pomeg. throat worms.
۵- Timely harvesting of pomegranates. This will reduce damage to the fruit due to the early cold and the cracking that results.
۶- After harvesting healthy pomeg., remove from diseased and damaged fruit and then store them in storage or cold storage.
۷-When harvesting, ensure that the fruits are not damaged.
۸-If you want to store pomegranates in a warehouse or fridge, cut them with 1.5 to 2 per thousand tequendazole solution of thiabendazole brand to prevent them from rotting.
Pomegranate fruit should be stored in 2 to 10 degrees Celsius with relative humidity of 80 to 90 percent for 4 to 7 months.
To buy Alternaria fungi causing the disease you can visit the fungi section of the site.
Alternaria rot of apples and pears
Alternaria rot of fruit is found in all countries with apple or pear gardens.
Symptoms of Alternaria rot: Symptoms on fruits are round, brown to black. They are dry and firm and shallow. These spots develop around the area of ruptured and damaged skin and the bumps of the abdomen and the tail of the fruit. Occasionally in the central circle around the ovary, a blackish-gray mold will grow and rot the fruit. But in a pear, the rotting of Alternaria rot starts from where the tail is cut and moves on to the rest.Occasionally in the central circle around the ovary, a blackish-gray mold will grow and rot the fruit. But in pear, the rotting starts from where the tail is cut and moves on to the rest.
Factor of the disease: The causive agent of Alternaria rot of pears the is Alternaria alternate. Another name is A. tenuis Nee. The conidiophores of this fungus are simple or branched. These conidiophores are formed individually or collectively. There are one or more conidia effects on conidiophores. The conidia of the fungus are chained and their surface is flat or warty. They are also golden brown.
Disease cycle of Alternaria rot of apples: It is a saprophytic fungus and is also known as a weak pathogen. Its habitat is dead and weakened tree tissues and feeds on apples and pears after or before harvest. This fungal pathogen enters the tree through weak or damaged tissues. These weak tissues can be injured or weakened by mechanical, chemical, physiological aging or sunburn.
Control of Alternaria rot of fruits: Avoid scars on the fruit during harvest.
Clean the boxes and equipment for transportation of fruits and clean with appropriate disinfectants.
If you use benzimidazole group fungicides to control stockpiling and postharvest disease, this will aggravate the alternative caries disease.
Alternaria fruit rot (postharvest disease)
Alternative fruit rot (postharvest disease)
Apple and pear fruits are affected by alternaria fruit rot, and in Japan and Korea the disease causes a great deal of pear damage. In most countries where apples and pears are grown, this type of caries is a common post-harvest disease.
Mostly on apple fruits with Alternaria fruit rot, round spots, brown to black, dry, firm and shallow usually formed around the ruptured and damaged skin or in the holes of the abdomen and ovaries. Occasionally, in the central area around the ovary, the black to gray mold grows and promotes decay in the meat. In pear fruit, decay starts from the place where the tail is cut.
The cause of the disease after harvest
Alternaria fruit rot is caused by Alternaria alternata. Another name for this fungus is A.tenuis Nees. The simple or branched conidiophores of this fungus are single or grouped, with one or more conidiic effects on them. The fungal conidia that are chained are golden- brown, smooth or warty.
A. alternata is a causative agent of Alternaria fruit rot, a weak saprophyte or pathogen that lives on dead and weakened tree tissues and attacks apple and pear fruits before or after harvest. The fungus attacks and infects fruits from weak or damaged tissue pathways as a result of mechanical or chemical damage, physiological aging and sunburn.
– To Control and prevention of Alternaria fruit rot (postharvest disease), the fruits should be carefully removed during harvesting and packaging to prevent scarring and contamination.
– Transportation and storage box of fruit should be disinfected with chlorinated water or water vapor before use.
If the fruits are sprayed with benzimidazole group fungicides after harvesting to control other storage diseases, the incidence – of alternaria fruit rot disease will increase.
Phytophthora rot of crown, collar and root of fruit trees
Phytophthora rot of crown, collar and root of fruit trees
Phytophthora rot of crown, collar and root are present in all countries where apples are grown, and damage is greater in areas that use apple shortening stands to plant these trees. The fungus has several varieties that generally cause three types of caries in the tree:
۱- collar rot
Phytophthora rot of collar is related to the transplanted parts. In this caries, the lower parts of the trunk show symptoms on the surface or above the soil (crown). This type of caries is most often caused by phytophthora in trees that their inplantations area is closer to the soil surface.
۲- Crown rot
Phytophthora rot of crown disease is related to the base part of the tree. In this case, the collar skin tissues (root and trunk junction) and the roots of the root of the plant invade and cause caries.
۳- root rot
Phytophthora rot of root involves the root system and parts farther from the collar, and usually occurs with the caries of the collar, although it can appear on its own. In Iran, this rot (crown and collar rot) is not common and does not cause much damage. It has been reported only in Shiraz, Miandoab, Karaj and Shahriar on apple tree.
Phytophthora rots are divided into two groups. The first batch of nonspecific symptoms develop on the diseased shoots. This means that the number of shoots this year will be slow, followed by a decrease in the number of shoots. The leaves are pale and appear purple in early autumn. Fruits sometimes shrink and color before they reach maturity. Therefore, the trees with the disease become weak and dry for a few years, but they can suddenly dry up.
The second type are specific symptoms, which include phytophthora rot, crown, collar and root. These symptoms are often not visible. To see the signs of crown and collar, you need to cut and remove the outer layers of skin to the root surface. In this case, the texture of the wood will be red rather than white, with the color orange to brown.
In Phytophthora rot, if you cut the brown textures of the crown in the inner part of the drainage vessels and in the surface layer of the wooden textures with a knife, a zebra or marble ribbon is seen. Occasionally you will see canker and collar rot and grime-like discharges, which is well visible in the ‘Cox Elbow Pain’ apple variety. In Phytophthora rot disease there is a clear boundary between the infected and the healthy area, and it is interesting to know that most of the fungal activity is at the same boundary, so you can sample the phytophoric caries of the fruit trees to isolate the fungus. In root rot, the roots turn brown and rot, after which saprophytic fungi attack them.
Disease agent (Click to buy disease agent)
Various species of Phytophthora have been recognized worldwide as the causative agent of crown, collar and root phytophthora rot, including P. cactorum globally. syringae in Europe and Canada, P.megasperma in Australia and the United States, P. cambivora in Australia, Japan and the United States, P.cryptogea in Australia and the United States, P. dreshslera and P. citricola in the United States. Be. In Iran, only P. cactorum species have been isolated from apple tree, which we have discussed in the following.
The mycelium of Phytophthora rot of fruit trees agent is colorless with no transverse walls. Older mycelia can be strapped. The asexual reproductive organs are zoospores. The zoospore is formed in sporangia. The sexual reproductive organs are called espore, which is caused by anthracite and eugenics fertilization.
P. cactorum is a hematological fungus. The sporangia are papillae and are sporadic in that they form sympodial on the sporangiophore. It has a parametric antride. In the solid medium, sporangia, eugenes and its spores are well formed. The appropriate temperature for the growth of this species is 26 degrees Celsius and the maximum temperature is 32 degrees Celsius.
Life Cycle and Epidemiology
P. cactorum, like other phytophthora rot of trees, has a wide range of hosts and attacks many crops. The fungus is an earthy species so it can be present in the area before planting. Phytophthora raw material can be introduced into the ground by seedlings or irrigated from the garden to remote gardens. Phytophthora survives after being transferred to the soil around the root of the tree as mycelium or ash in the infected tissues of the host plant or ash in the residues of organic matter or soil. According to the researchers, the main factor in the survival of the fungus in the absence of the plant is that it can also live on fallen fruits on the ground. The most important source of infection in phytophthora rot is zoospores. The optimum temperature for the formation of zoospore within the sporange is about a few degrees lower than the temperature appropriate for mycelial growth. The higher the number of sporangia that cause phytophoric rot in grain trees when the soil moisture is saturated or close to it, so the places where water accumulates for a long time provide conditions for the outflow of zoospores and their propagation elsewhere. Earth provides. According to research, the cause of the movement of zoospores to the roots and crowns may be a chemical phenomenon.
Blue mold rot of fruit
Blue mold fruit rot
Other names for blue mold rot are “soft rot” and “wet rot”. Its name is due to the blue color of the fungus spores. It is present in all parts of the world where apples are grown. Countries that have traditional or non-standard warehouses for storing apples are more severe and in Iran is one of the most important cause of apple fruit rot.
Symptoms of blue mold rot
In the Blue mold rot, the fruit first develops watery, soft spots and develops within the tissue at temperatures of 20 to 25 degrees Celsius. In this type of disease, a clear border is visible between the infected area and the healthy area. In humid conditions, the surface and central part of the blotch or margin of its clefts is covered with a cotton-like layer and a prominent mass, such as blue-green. These are asexual fungal spores of blue mold rot and contaminate healthy fruits in adjacent boxes and containers.
Factor of fruit rot disease
The most common species of Penicillium isolated from diseased seeds(Blue mold rot) is P. expansum and it has been isolated in Iran. The conidia and conidiophores in this fungus form in small clusters almost similar to curium. Depending on environmental conditions and species of fungi, conidia are formed either at or near the edge of the caries.
Disease Cycle and Epidemiology
Pathogenic fungus of Blue mold rot of fruit can survive in the soil in winter. Its containers are also left in contaminated transport boxes or storage walls and are always present in the open and in loading and storage areas.
In other countries, spores can prolong the life cycle of the fungus during the summer and other seasons on infected fruits inside the cellar and in the refrigerator, contaminated washing solutions or spores themselves.
Penicillium, the agent of Blue mold rot is often known as a wound parasite, but it can also enter through fruit lenses and cause fruit rot. The disease is often seen on injured fruits and fruits that have fallen to the ground and crushed. Hail can also cause this scar and the way to the fruit. Also caries caused by other pathogens on the fruit can become a place of entry for Penicillium fungi. The fungus (agent of Blue mold rot) can grow up to zero degrees Celsius, but overall the growth and transmission of the fungus is higher at warmer temperatures. Penicillium species usually produce a heat-resistant fungal toxin (fungal toxin) called “patulin” so avoid eating contaminated fruits.
Combating penicillium blue fruit rot
۱- Observing scientific and technical points during harvesting and care of fruits in warehouses and cold stores to prevent pathogen transmission to them and not to injure them.
۲- Complete disinfection of boxes, containers and storage areas with suitable fungicides and separation of infected fruits from healthy fruits.
۳- Pre-harvest spraying with benzimidazole group fungicides and washing and immersing fruits in water containing suitable fungicides. During experiments in Iran, immersion of wounded fruits in thiabendazole and benomyl toxins solution was able to control Blue mold rot of fruit disease. The immersion time should be 20 minutes.
۴٫ Treat the fruits quickly with calcium chloride after harvest. This solution increases the calcium in the fruit and increases its resistance to decay of the blue mold.
۵٫ Biological control of this pathogen is possible and experiments based on fungal, bacterial and yeast biological controls can be hoped for and used in this way.
Rhizopus rot of fruit
Rhizopus rot of fruit disease is often present in all areas where apples are grown. Pathogenic fungi are more likely to attack injured fruits, frozen or those that are over-ripe and stored outdoors.
Initially, brown and soft spots appear on the fruit in rhizopus rot of apple. At 25 degrees Celsius, the fungus grows high and develops rapidly in the fruit, eventually becoming watery, dark, and soft. If you remove the fruit skin at the spots, the leachate will come out and give it a sour smell. The fungal mycelia will appear white on the decayed and crushed portions, and black spores will form on the surface.
Cause of disease
The fungus responsible for fruit rot disease is called Rhizopus stolonifer and has been reported on apples and pears in Iran. This fungus is synonymous with R. nigrican Ehrenb. The asexual reproductive organs are sporangiospore which is produced in sporangia. Its sexual reproductive organs are called zygospores. Zygospores consist of colonies of two sexes that are compatible.
There are asexual spores of Rhizopus rot in various places, such as fruit boxes, harvesting and moving locks, warehouses and even in the garden. Asexual spores germinate on infected and injured fruits and cause infection. Healthy fruits next to infected fruits can be directly infected by this fungus, thus causing a bulk rot.
۱٫ Preventing apple rot by removing the primary inoculum of Rhizopus rot of fruit and spraying the fruit trees before the fruits are harvested to kill pests that injure or pierce the fruit.
۲٫ Picking the fruits in the proper handling stage and carefully and carefully moving to prevent them from being injured and also immersed in special fungicides.
۳٫ Rhizopus stolonifer mycelia are unable to grow at temperatures below 4.5 ° C, so they can be effectively controlled by timely and rapid cooling of the fruits after being harvested.
Phytophthora rot of apple fruit
Phytophthora rot Disease Apple is found in apple orchards where trees with root, crown and collar phytophora decaying and their severity is even greater on trees with shortening stems. Fruits get the disease when they are on the tree. The development of the disease in Iran is based on the yellow and red Lebanese apple species kept in storage.
Initially, brown spots appear on the surface of fruits with decaying phytophthora, which then progresses to the fruit flesh and develops irregularly within the fruit. During the development of fruit infestation completely rots. The discernible boundary between the healthy tissue and the infected tissue in the fruit cannot be seen, so that the healthy parts cannot be easily separated from the infected parts. Although the texture of the fruit is spongy, its shape is maintained. If you cut the fruit transversely, you can see its brownish-colored pots.
cause of disease
Phytophthora rot of apple fungus has been determined by Phytophthora cactorum. This species lives in the soil and its transmission and its initial inoculation in Iran are usually in cold storage and non-sanitary warehouses. In these places, contaminated apple fruits fall to the ground and turn the cellar into a source of contamination. Outside storage, raindrops can lift the fungus from the soil and onto the branches near the ground. Another important point is that Phytophthora cactorum is also able to grow and develope in temperature and cold conditions.
Disease control of apple fruit rot
The first effective measure for the control of Phytophthora rot of apple fruit is prevention. All fruits that fall to the ground should be placed in a separate place from the healthy and new fruit and never touch each other. In other countries around the world there is a late spraying process to control fruit rot due to phytophthora, as well as gray rot, etc. Folptan and diclofluoride toxins can be used. Another way is to wash the fruits with metalloxylate, which can eradicate the primary diseases of the fruit as well as control the secondary rot diseases in the fridge and storage room of the fruit.