What is the amount of pests and diseases that occur, and what pests and diseases will be

The occurrence of pests and diseases, i.e., the pest index of the crop. The occurrence of insect pests is generally expressed by two indices: insect plant rate and insect population density. The degree of disease is generally expressed by the rate of diseased plants and the infection index.

The combination of pests and diseases, diseases and insect pests often have adverse effects on agriculture, forestry, animal husbandry, etc.

The causes of the pathogenesis of medicinal plants include biotic and abiotic factors. Diseases caused by biological factors such as fungi, bacteria, viruses, etc., which invade the plant body, are infectious, called infectious diseases or parasitic diseases, and diseases caused by abiotic factors such as drought, waterlogging, severe cold, nutrient imbalance, etc., which affect or damage physiological functions, are not infectious, and are called non-infectious diseases or physiological diseases. In infectious diseases, the pathogenic parasites are called pathogenic organisms, among which fungi and bacteria are often called pathogenic bacteria.

The infected plant is called the host plant. The occurrence of infectious diseases not only depends on the role of pathogenic organisms, but also is closely related to the physiological state of the host and the external environmental conditions, which is the result of the interaction between pathogenic organisms, host plants and environmental conditions.

The occurrence of insect pests refers to the number of insect populations per unit of plant; Generally, it is expressed by two indices: insect plant rate and insect population density; The degree of disease is generally expressed by the rate of diseased plants and the infection index.

It is the disease and pest index of crops, and the occurrence of insect pests refers to the number of insect populations per unit plant; Generally, it is expressed by two indices: insect plant rate and insect population density; The degree of disease is generally measured by the rate of diseased plants and the infection rate.

It is the pest index of the crop.

Summary. Pest and disease outbreaks"with"Pest and disease outbreaks"Both are expressions that can be used, but in Chinese, they are generally used"Pest and disease outbreaks"More common and accurate. "Outbreak"The term indicates a rapid increase in the number of diseases or pests, the situation is severe, sudden and transient.

Pest and disease outbreaks"with"Pest and disease outbreaks"All of them can be used in the expression Fang Lu Ye Lu style, but in the Han language, it is generally used"Pest and disease outbreaks"More common and accurate. "Outbreak"The term indicates a disease spine or a rapid increase in the number of pests, a serious situation, with suddenness and transience.

Can you add, I don't quite understand it.

While"The source of the outbreak is buried"It emphasizes the meaning of violence and sudden outbreaks, and is generally more suitable for describing violent events, diseases, wars, etc. Therefore, from a semantic point of view, hail spring ants, used"Pest and disease outbreaks"It is more in line with the expression of the rapid increase in the number of pests and diseases, the senkey and the serious situation.

Pests and diseases include wilt, powdery mildew, leaf spot, blight, virus disease, white silk disease, umbilical rot, gray mold, rust, mosaic disease, aphid, thistle grinding horse, red spider, leaf miner, whitefly, head lice, pubic lice, locust, thrips, noisy wide shellworm, etc. There are certain differences in the pests and diseases of different crops.

Pests and diseases are the combination of diseases and insect pests, and Hengwu often has adverse effects on agriculture, forestry, animal husbandry, etc.

Example sentence Zhenzhen: "Since the beginning of spring this year, the situation of pests and diseases in the western part of our province has been strictly completed. "There are many people who spray pesticides to prevent pests and diseases.

Spraying pesticides can eliminate most diseases and pests, but some are more tenacious and develop resistance. Pesticide research and development units need to continuously develop new products to deal with pests and diseases.

Pests and diseases: A combination of diseases and pests. Disease refers to the fact that in the process of cultivation, the plant is affected by the infection of pests or adverse environmental conditions, the normal metabolism is disturbed, and a series of changes and damage occur from physiological functions to tissue structure, so as to present abnormal lesions in the external morphology, such as wilting, rotting, spots, mold powder, flowers and leaves.

There are many types of animals that harm medicinal plants, mainly insects, but also mites, snails, rodents, etc. Although many insects are pests, they are also beneficial insects, and beneficial insects should be protected, propagated and utilized. The methods of pest control are:

Agricultural control law, biological control law, physical control law, mechanical control law and chemical control law.

Agricultural Pest Occurrence Amount: Pest Occurrence is the change in the number of pests in the future, and it is decided whether to control it. In particular, intermittent pests such as armyworms occur in varying amounts from year to year, with rampant occurrences causing devastating infestations and very few occurrences in normal years.

It is especially important to carry out the occurrence of ** for this type of pest.

The occurrence amount** is mainly based on the base number of the previous generation (or previous insect stage) of the pest, combined with the comprehensive analysis of the main environmental factors (such as climate, food, natural enemies, etc.) that affect the change of pest population, and find out the correlation between them**. However, due to the intricate action of many factors on pests and determine whether pests occur largely, we must analyze the dominant factors that determine the occurrence of pests as predictors in order to gradually increase the level of pest occurrence. To achieve this, the basic work is to do in-depth and detailed investigation and research work on specific pests, accumulate data for a long time, and continuously conduct comprehensive analysis.

The growth and decline of a pest population is mainly determined by three factors. The first is the basic number of individuals in the population (referred to as the base number), especially the number of females that can reproduce; the second is fertility; The third is the mortality rate of the population. If the causes of individual mortality in pest populations are mainly physiological causes of stunting, adverse climatic conditions, parasitism or predation of natural enemies, lack of food, etc., the cause of death must be found out when doing survival table analysis.

Diseases are divided into infectious and non-infectious diseases (physiological, natural damage), i.e., damage.

From the first element: the disease is caused by the first child, the injury is not, it can be caused by animal and plant injuries, or natural injuries and other factors.

From the onset of symptoms: the disease depends on the fungus, the bacterial infection, there are different secretions, and the color of the symptoms, such as the bacteria are pus.

From the distribution of the disease: the damage may be local, with obvious non-spreading, but the invasion of germs has obvious spreading, and generally occurs in large areas.

Pests: As the name suggests, it is caused by insect damage, and the first cause is different.

Secondly, the symptoms are different, insect pests generally have gnawing, flowers and leaves, yellowing, leaf rolling, root breakage and other phenomena in all parts of the plant. . . Diseases are generally different, and the most striking feature is that the disease secretions are obvious.