Papaya rust is the main disease of papaya, what are the symptoms of papaya rust?

In the early stage, the infected leaves will appear yellow dots, and rusty spore organs will grow in the bulging areas, and in the later stage, the infected infusion will form black lesions, and the leaves will fall off or die.

It is that you will find that there will be some spots on the surface of the papaya, and there will be some black and brown spots on the top of the page, and the leaves will be yellow and have the symptoms of wilting.

There will be some spots on the leaves of the papaya, there will be some rotten places, there will also be some black spots or rotten places on the papaya, there will be a smell, and the papaya will also fall if it is serious.

There is a change in taste, but this is only the preliminary hydrolysis of the pulp tissue, there are no harmful bacteria, and if a papaya has a small area of soft rot, people will be fine if they eat it. Of course, if you have mycelium, you won't eat it if you see it, and the vegetables are all bad, so don't eat it anymore, in fact, how many people have really thrown it away? If it is broken, it depends on how bad it is, if there are only a few mold spots on the surface, it can still be eaten, if it has rotted a third or more, then don't eat it, or throw it away.

The papaya is a little bad and can't be eaten. Papaya has a lot of moisture, and once mold grows, it is easy to penetrate, causing the whole papaya to be contaminated by mold. Once the papaya is moldy, it should be thrown away, otherwise it will have an impact on your health if you eat it for a long time.

The flesh of ripe papaya is soft and not easy to preserve, so it should be eaten immediately after purchase. If you don't plan to eat it immediately after buying, it is recommended to choose a slightly green color that is not yet all yellow, and leave it for 1 to 2 days after returning home, and then wrap it in newspaper and put it in the refrigerator.

It is not easy to store and should be eaten immediately after purchase. If you don't plan to eat it immediately after buying, it is recommended to choose a little green color that is not yet all yellow, and leave it for 1 to 2 days after returning home, and then wrap it in newspaper and put it in the refrigerator for about 4 to 5 days. The papaya is a little bad and can't be eaten.

Papaya has a lot of moisture, and once mold grows, it is easy to penetrate, causing the whole papaya to be contaminated by mold. Once the papaya is moldy, it should be thrown away, otherwise it will have an impact on your health if you eat it for a long time.

The harm of rust not only affects vegetable farmers who grow onion and garlic vegetables all over the country, but also closely related to the diet of each of us. Therefore, it is quite necessary to understand this rust that harms onion and garlic vegetables. If the garlic farmer is working in the field at this time, this reddish-brown "rust" will also stain the trouser legs the color of red rust.

In addition, other vegetables (e.g., green onions) and field crops (e.g., wheat, corn) and even fruit trees (e.g., pear trees), flowers and plants can also be infected with rust.

Some pesticides can be sprayed, and some pesticides are specifically designed to control rust.

Once you find that this is the case with papaya, you should spray pesticides, dilute the pesticides with water, add them three times a day, spray them on the roots and leaves, and then reduce the temperature to control the disease.

If you want to prevent papaya rust, you should give papaya sufficient nutrition, enhance resistance and apply pesticides to get rid of germs.

When the flowers in the flowering stage are separated, the bracts and sepals tips of the diseased flowers will show small brown lesions, with the continuous infection of the pathogen, the pathogens will develop along the main vein to the base of the flower cluster, and then cause the flower base rot or even the peduncle rot, and the disease spots will soon spread to the surface of the whole fruit, and gradually erode to the pulp, so that the whole fruit rots. If the young papaya fruit is diseased, if the diseased fruit loses water, it will turn into a brown stiff fruit and hang on the branch for a long time without falling. In turn, it affects the income of papaya, resulting in production losses.

The next spring, when 30% of the seeds are white and germinated, they can be sown. After sowing, the thickness of the covering soil is about 3 times the diameter of the seed. Watering to keep the ground moist, when the seedlings grow 3 true leaves, the plant spacing is 15 20cm; When the number of true leaves grows to 6, increase fertilizer and water management, and combine foliar fertilizer spraying with ground manure.

Papaya brown rot overwinters in stiff fruits or cankers on diseased branches. In the following year, conidia were produced and spread by the wind, and the initial infection occurred. The pathogen can invade the fruit through the stomata and skin pores, but mainly through the wound.

The disease is most severe in the near-ripening stage of the fruit. The temperature is 20-25, rainy and foggy <>

Lesions can occur anywhere on the fruit surface, and the initial lesions are round and light brown. The diseased part expands and rapidly spreads to the whole fruit, which is brown and water-stained, soft and rotten. Under humid conditions, the disease grows soft, sparse white hyphae that cling to the surface of the fruit and form a thin layer.

Sweet orange fruit occurs more often. Lesions can occur anywhere, initially superficial, light brown, and rapidly expanding. Then it becomes soft and rotten.

It forms a white mycelial film against the fruit surface.

Initially there are small water-stained spots, then dark green or brown lesions, and when the weather is wet, the lesions spread to the base of the young shoots, causing the whole new shoots or the whole seedling to turn brown and die. There was no obvious rot symptom in the roots before the seedling died. Finally, the whole plant is covered with a layer of white moldy substance, and in severe cases, the plant is yellowed and dies.

First of all, we can prevent the occurrence of this disease through reasonable dense planting, and secondly, we can use new high-lipid membrane solution to prevent and control it in the early stage of the disease.

The symptoms of papaya brown rot are some brown spots on the rhizomes of papaya, and these spots are accompanied by rot, and this rot will gradually develop to the pulp, and finally cause the whole fruit to rot.

The symptom is that the leaves are particularly yellow, and the leaves will fall, and large plants will die, and they will not bear fruit.

There are some brown rot spots on the fruit, and as these patches grow larger, the fruit becomes some stiff fruit.

This condition is generally characterized by brown spots on the fruit, which are mainly round in shape, and the lesions will expand widely, extending to the surface of the whole fruit, gradually extending to the pulp, and eventually causing the whole fruit to rot.

I know a little bit about this, so I'll tell you about it

1. Papaya brown rot

1. Pathogenesis.

Papaya brown rot overwinters in stiff fruits or cankers on diseased branches. In the following year, conidia were produced and spread by the wind, and the initial infection occurred. The pathogen can invade the fruit through the stomata and skin pores, but mainly through the wound.

The disease is most severe in the near-ripening stage of the fruit. The temperature is 20-25, and the rainy and foggy climatic conditions are conducive to the occurrence of this disease. Pests such as bugs often create opportunities for germs to invade.

When the fruit comes into contact with the diseased fruit, the germs can invade the fruit from the harmless part and continue to infect the fruit during storage. The fungus enters the flower apparatus and invades the stigma or nectar gland through the bud tube, and when the papaya blooms in case of rain and the temperature is low, it is prone to flower rot. During the growth period, when conditions are suitable, re-infection of the bacteria continues.

2. Harmful symptoms.

Papaya brown rot mainly damages fruits, but also flowers and shoots. Fruits can be harmed from young fruits to ripening and storage periods, and the damage is most severe in the late growth and storage periods. The flesh was dark brown and wet rot, and gray-brown mold bushes appeared on the surface of the diseased part, which were irregularly distributed on the fruit surface and generally not in concentric rings, which were slightly different from the symptoms of kernel fruit brown rot.

After the whole fruit rots, it shrinks into a stiff fruit, which is dark brown or black, and the stiff fruit often hangs on the tree for a long time. When the petals and stigma are infestation, brown spots first appear, and then gradually spread to the calyx and peduncle, and then the flower parts turn brown and wither. When the weather is humid, the diseased flowers decay quickly, and gray mold appears on the surface.

If the weather is dry, it will wilt and dry up, and the diseased flowers will not fall off on the residual branches. The young leaves are damaged, browned and wilted, and if they are damaged by frost, the diseased leaves will not fall on the branches.

The mycelium of the fungus spreads to the new shoots through the peduncle and petioles, and can further expand to larger branches, forming oblong canker spots with purple-brown edges and slightly concave gray-brown. When the ulcer begins to form, the phenomenon of gum flow often occurs, and then the cortex becomes brown and rots, and the diseased part immediately decays, and the periphery is slightly raised. When conditions are right, the diseased part surrounds the branch and causes the branch to die.

The ulcers of the damaged leaves and branches all have gray mold growth.

2. Pollution-free prevention and control measures

1. Strengthen management.

In winter, remove dead fruits and diseased branches in the garden and on the trees, and bury them deeply or burn them. Combined with the deep turning of the orchard soil, the diseased fruits and other diseased residues remaining on the soil surface were turned into the soil.

2. Pharmaceutical prevention and control.

Spray 5° beite sulfur mixture or other shoveling agent before germination. After flowering to 1 month before harvesting, spray stone sulfur mixture or lime sulfur mixture, lime sulfur mixture formula is: sulfur powder 4kg, slaked lime powder 2kg, soybean milk 1kg, water 250kg, or spray 50% carbendazim wettable powder 600 800 times liquid, etc., the number of spraying depends on the specific occurrence of the disease.

Papaya fruit pests such as peach borer, when the papaya fruit swells, the larvae bite through the peel and bury into the fruit. It not only eats the pulp vertically and horizontally, but also causes insect wounds and allows germs to invade. Therefore, the control of such pests is also an important part of the prevention and control of papaya brown rot.

The most serious is the damage to the fruit, the fruit is early on the disease, showing small brown round lesions, and it will also pose a serious threat to the papaya trunk, affecting its normal transportation of oxygen and water, resulting in branch death;The most effective control is the use of drugs, before the germination of papaya in early spring, use relevant drugs, wait until the papaya flowers are gone, and then use relevant agents on it, in addition to actively prevent pests.

There will be rotting pulp, or the phenomenon of fruit dropping, and there will be various disease spots, disease infection, and papaya water shortage. Integrated pesticide control can be used, or through fertilization, or through management to avoid disease problems.

Small brown spots will appear on the fruit, which will gradually expand and then extend to cause the fruit to rot. Prune the branches and leaves regularly, cut off the problematic branches and leaves, and then spray some chemicals.

Leaf blight: It is harmful to leaves, and it is seriously damaged in July and September. Prevention and control methods: clean the countryside in winter;In the early stage of the disease, it is prevented and treated with 1 1 100 Bordeaux solution or Dakoning, promethine and other agents.

Papaya rust: it is harmful to leaves and petioles, young shoots, young fruits, etc. Control methods: choose a place where there are no pine and cypress trees in the vicinity of 3 to 4 kilometers to plant papaya; In the early stage of the disease, it was prevented and treated with 25% powder rust 1000 1500 times solution.

It mainly harms the fruit, followed by the leaves, petioles and stems. Yellow or dark brown water-stained small spots first appeared on the face of the Lu tribe of the damaged fruit, and with the gradual expansion of the lesions, the middle of the lesions was concave, and concentric ring patterns appeared, and the small black spots (conidia discs) resistant to the protrusions were arranged in a wheel-like manner, and the vermilion sticky dots (conidia clusters) were present when wet, and the flesh under the lesions was hardened. The lesions on the leaves mostly occur at the tips and margins of the leaves, brown, irregularly shaped, there are small black spots on the spots and the petioles, and the petioles mostly occur in the petioles that are about to fall off or have fallen off, and the junction between disease and health is not obvious, and there are small black dots or vermilion sticky spots on it.

Papaya needs scientific management, regular killing, reduce the spread of aphids to the virus, followed by the papaya plants that have been diseased, timely removal, prevention and control of pathogenic bacteria further spreading, regular cleaning of fallen leaves and fruits in the yard, weeds and branches, prevention and control of germs breeding stool, papaya rust can be used azole agents, aphids can be controlled with imidacloprid and other agents, peach borer using bagging technology for control.

Common diseases in papaya cultivation.

1. Papaya mosaic disease:It mostly occurs in the warm and dry season, harms the leaves, stems, flowers and fruits of the whole plant, and the loss is great, and the symptoms mostly start from the leaves, showing spots in the shape of water stains, affecting photosynthesis, resulting in insufficient absorption of nutrients by the plant, resulting in symptoms such as curling up of new leaves, necrosis and falling off of old leaves, and insufficient fruit size.

2. Papaya rust:This pathogen has strong survivability, can overwinter in the soil, and wait for the next spring to bloom to form spores, with the help of wind to spread, especially when the rain is sufficient, it is easier to multiply in large quantities, it is a high incidence period of disease, not only harming the leaves and petioles of papaya, but also endangering the growth of new shoots and young fruits of the plant, reducing yield and income.

Cultivated papaya is the main pest.

1. Aphids:Aphids mainly harm the young leaves of papaya, as well as the new shoots that have just been extracted, etc., generally the papaya leaves with aphids will be curled, and the papaya tree generally bears few fruits, and the fruit does not grow large, and the overall tree is very poor.

2. Peach borer:The peach borer is the most harmful to papaya is its fruit, which is mainly based on larvae, it is perennial bored into the papaya fruit, which has a great impact on the quality of the papaya fruit.

Papaya pest control.

1. Papaya mosaic disease:In the later planting, scientific management, regular killing, reduce the spread of aphids to the virus, followed by the papaya plants that have been diseased, timely removal, prevention and control of the further spread of pathogenic bacteria, regular cleaning of fallen leaves and fruits, weeds and branches in the yard, prevention and control of the breeding of germs.

2. Papaya rust:For the prevention and control measures of papaya rust, it is best for us to use its transmission characteristics to prevent in advance, when planting, try to stay away from the forest of juniper wood, to ensure that there is no such tree within 2 kilometers, can effectively cut the latent rust pathogen and the spread of spores, and can also use azole agents to spray and prevent when the plant has just sprouted.

3. Pests:In order to avoid the harm of aphids, you can use trapping, and you can also use imidacloprid, deltamethrin and other agents for control.