Plum sack disease is a fungal disease of ascomycetes that seriously affects the yield and quality of plums. It is important for growers to understand the pathogenesis, identify symptoms, and adopt comprehensive prevention and control strategies.
In this issue, Qingjiang Crane will focus on and chat with all the teachers about the relevant knowledge of plum "bag fruit disease", aiming to discuss the pathogenesis and symptoms of plum bag fruit disease with you in detail, and put forward effective prevention and control measures and efficient drug selection. I hope it will be helpful to you, and I will forward and share the pictures and texts of this issue.
Picture 01~02): Plum suffers from saccharberry disease
The pathogenesis of plum sac fruit disease is "similar" to that of peach leaf shrinkage disease:
Plum saccharides are mainly caused by ascomycetes and fungi, and their pathogenesis is complex, which is closely related to environmental conditions and healthy growth and development of trees.
The climatic conditions of low temperature and high humidity are conducive to the reproduction and spread of the pathogen of plum bag fruit disease. The optimal germination time of pathogenic bacteria is 11°C~20°C. The maximum will not exceed 26°C. Orchards with weakened trees, poor soil moisture, and excessive moisture are more susceptible to disease.
The pathogenic bacteria are safe in the winter on the scales of plum buds, in the crevices of scales, or in the diseased skin of branches, and spread through natural wind and rain, insects and other media, invading the young leaves of plum or the skin of fruits, causing disease in leaves or fruits.
Picture 03~04): The young fruit stage is the period when plums suffer from sac fruit disease
The main symptoms of plum saccharocyst disease are distorted "bag-shaped" seedless and soft:
The symptoms of plum sac fruit disease are mainly manifested in the fruits. After the plum flowers and sets the fruit, it can show the typical characteristics of "hitting" on the young fruit.
Water-soaked spots appear on the surface of the fruit at first, and the young fruit is round or bag-shaped. As the disease progresses, the spots gradually enlarge and take on a brownish color. The young fruit becomes narrow and curved like the moon, and the surface of the diseased fruit is smooth and shiny, and the skin is light yellow to red, which shrinks and becomes gray, or dark brown, or black and falls off.
There is no pit in the diseased fruit, and only the prototype of the pit that is not well developed is visible. The fruit is distorted and hollow. The internal tissues of the fruit begin to deteriorate, eventually causing the fruit to deform and shrink, forming the so-called "sac fruit". Severely diseased fruits may fall off early, seriously affecting yield.
Picture 05~06): Plums with a high fruit set rate
In addition to harming young fruits, the pathogenic bacteria of plum "bag fruit disease" can also infect the growth and development parts of plums such as leaves and branches of fruit trees. The diseased branches are grayish-white, slightly swollen, and have a "soft feeling" between the branches and the xylem. Diseased leaves (the incubation period of the pathogen has passed) can show symptoms at the plum flowering stage, the leaves turn red or yellow, and the leaf surface is uneven, which is very similar to the "leaf shrinkage disease" on peach trees.
Comprehensive prevention and control strategy of plum bag fruit disease:
Comprehensive prevention and control strategies should be adopted for plum sack fruit disease, including agricultural control, biological control, physical control and chemical control.
01) Agricultural prevention and control of plum "bag fruit disease":
Strengthen orchard management and improve the comprehensive stress resistance of trees. Reasonable fertilization to enhance tree potential, timely pruning, keep the canopy ventilated and light-transmitting, remove diseased fruits and branches, and reduce the source of pathogenic bacteria and the incidence base of sack fruit disease.
Picture 07~08): different varieties of plums
02) Biological control of plum "sac fruit disease":
Use biological resources such as natural enemies and antagonistic bacteria to control the reproduction of pathogenic bacteria. For example, natural enemy insects are introduced to prey on insects that transmit pathogens, and antagonistic antimicrobials are sprayed to inhibit the growth of pathogenic bacteria. This estimate cannot be quickly realized in a short period of time.
03) The chemical prevention and control of plum "bag fruit disease" is also the most "reliable" method for the prevention and control of plum "bag fruit disease":
In the early stage of the occurrence of plum "bag fruit disease", high-efficiency, low-toxicity and low-residue chemical agents are selected for prevention and control.
When spraying, it is necessary to use the application tools with good atomization effect to achieve uniform and thoughtful spraying, to ensure that the fruits and leaves are fully applied, and the liquid medicine is evenly attached to the leaves, young fruits and branches on the surface, so that it is advisable not to drop. At the same time, pay attention to the rotation of pesticides to avoid the development of drug resistance of pathogenic bacteria.
Image 09~10): high-quality and high-yield plums
The choice of medicine for plum "sac fruit disease" is also a "technical work":
For plum sack disease, there are a variety of highly effective agents available on the market. When choosing pesticides, fruit farmers should not only fully consider the disease prevention effect of pesticides, but also consider the safety of pesticides and the impact on the environment.
Commonly used high-potency agents include sulfur, carbendazim, thiophanate-methyl, dicyananthraquinone, and difenoconazole desen and other compound preparations. These agents have the characteristics of broad spectrum, high efficiency and low toxicity, and can effectively control the occurrence and spread of plum bag fruit disease.
You can also spray 1000~1200 times of 25% dicyanthraquinone thionazole strobin suspension, or 1500~2000 times of 40% dicyanthabhanate thioquinone thioconazole strobin suspension, or 43% thiophanate-methyl tebuconazole suspension or 48% thiophanate-methyl tebuconazole suspension 500~600 times liquid spray, or 80% thiophanate-methyl tebuconazole wettable powder or 80% thiophanate-methyl tebuconazole water-dispersible granules 600~800 times liquid spray stems and leaves.
Picture 11~12): Prunes that are free from pests and diseases
However, it should be noted that pharmaceutical prevention and control is only one part of the comprehensive prevention and control strategy and cannot be overly relied on. In the prevention and control of plum bag fruit disease, fruit farmers should adhere to the principle of prevention first, comprehensive prevention and control, and adopt a combination of various means to achieve the best control effect.
Written on the back of the comprehensive prevention and control of plum "bag fruit disease":
In summary, plum sack fruit disease is a fungal disease that seriously affects the yield and quality of plums. Fully understanding the pathogenesis, symptom recognition and comprehensive prevention and control strategies are the keys to the prevention and control of plum "sac fruit disease".
By strengthening the comprehensive application of orchard management, biological control, physical control and chemical control, the occurrence and spread of plum bag fruit disease can be effectively controlled, the economic benefits of fruit farmers and the enthusiasm of plum planting can be guaranteed, and the sustainable development of plum planting can be ensured.
Picture 13~14): high-grade fruit with a very high appearance