Identification methods and control measures for crop phytotoxicity and disease

When planting crops, phytotoxicity and disease can easily lead to confusion among farmers. Because the causes of phytotoxicity and disease are different, their control measures are also different. Therefore, the identification of phytotoxicity and disease is well done, and targeted prevention is critical for crop growth.

Identification method of crop phytotoxicity and disease

1: difference between spotted phytotoxicity and physiological disease

The distribution of spotted phytotoxicity on plants is often irregular, and the whole field is also light and heavy. Physiological diseases usually occur, and the symptoms of plants appear more consistent. Spot-type phytotoxicity and fungal phytotoxicity are also different. The former has a large change in spot size and shape; the latter has a disease center and the spot shape is relatively uniform.

2: The difference between yellowing type phytotoxicity and deficiency yellowing

The yellowing caused by phytotoxicity often develops into dead leaves from yellow leaves, with plenty of sunny weather and rapid yellowing; lack of yellowing of nutrients, more rainy days, slower yellowing, and yellowing often with soil fertility and fertilization The level is related and the performance is consistent in the whole field. Compared with the yellowing caused by the virus, the yellow leaves of the latter often have broken green and strong performance, and the diseased plants show systemic diseases, and the diseased plants are mixed with healthy plants.

3: The difference between malformed phytotoxicity and viral disease deformity

Malformations caused by phytotoxicity are common, and local symptoms are manifested on plants; malformations caused by viral diseases are often sporadic, often accompanied by symptoms such as broken green, clear veins, and wrinkled leaves.

4: The difference between the wilting of the phytotoxicity and the wilt of the infective disease

The wilting caused by phytotoxicity has no morbidity center, and most of them have a slow process, first yellowing, post-dead strain, no browning of roots and stems; the wilting caused by invasive diseases is mostly obstruction of tissue obstruction, in sunny, evaporation When it is big, it will first wilting, and then it will lose its green and dead plants. The root catheter often has browning.

5: The difference between the slowness of phytotoxicity and the stiffness and deficiency of physiological diseases

The stagnation caused by phytotoxicity is often accompanied by symptoms of plaques or other phytotoxicity, while the physiological toxicosis is characterized by poor root growth, and the dysfunction of the deficiency is yellow or dark green.

Crop phytotoxicity and disease control

Crop phytotoxicity control

1. Strengthen the supervision and management of pesticides and improve the quality of pesticide products

The pesticide management department shall strictly approve the examination and registration procedures for pesticide production, strengthen the quality inspection, and prohibit the production of counterfeit pesticides. At the same time, pesticide production enterprises shall, in accordance with the provisions of the “Administrative Measures on Pesticide Labelling”, indicate the Chinese common name, content, dosage form, registered crops and control objects, application methods and dosages, precautions, etc. of the active ingredients of pesticides. The contents marked must be registered with the Ministry of Agriculture. The approval of the agreement shall not be modified without authorization.

2. Strictly apply the scientific medicine according to the requirements

In the process of using pesticides, it is necessary to fully understand the nature of the drug, whether the application of the drug is symptomatic, strictly follow the label instructions, grasp the precautions for the use of the drugs used, control the dosage and concentration, and select the correct period and method of use. First, it must be used strictly in accordance with the prescribed scope and dosage, and should not be expanded or increased at will. Second, apply the drug evenly at one time to avoid repeated medication. Third, do not mix pesticides, so as not to aggravate the phytotoxicity. Fourth, when applying herbicides, especially broad-spectrum herbicides, the wind direction should be observed and the windshield should be installed on the nozzle to avoid harming the crops of adjacent fields. Fifth, we must pay attention to avoid the use of pesticides that have residual phytotoxicity to the crops.

3. Do a good job in testing, demonstration and promotion of pesticides

For newly introduced pesticides that have not been used in the local area, a small-area test must be carried out before application to determine whether the crop is suitable, safely used, the method of use and the results of the use period. Through the test, the application technology of the dosage, the appropriate period of application, the application method, etc., which are suitable for the local climate, soil quality, farming system, etc., can be obtained, and the response of the growth stages of the crop to the sensitivity of the medicament and the conditions of the occurrence of the phytotoxicity are clarified. Use these experiences before promoting them.

4. Improve the level of preparation and application of pharmaceuticals

Pay attention to the preparation method of the medicament (such as the blending of Bordeaux mixture and stone sulphur mixture, the choice of river water or fresh water for dilution water, and try not to choose well water, etc.) to reduce the possibility of occurrence of phytotoxicity. Pay attention to the characteristics of the crops to be protected and the characteristics of different growth periods, master the crop types sensitive to the medicaments and the resistance ability of the crops at different growth stages, and select suitable pesticides and dosages to avoid the occurrence of phytotoxicity. Pay attention to the environmental conditions during application, high temperature in summer (above 30 °C), strong sunlight, relative humidity below 50%, wind speed over 3 (>5 m/s), rainy days or dew can not be applied, otherwise It is easy to produce phytotoxicity. When mixing pesticides, pay attention to the applicability of the mixed pesticides used for crops.

5. Implement the policy of “prevention first, prevent problems before they happen”

After the occurrence of phytotoxicity, it is futile to rely solely on crop self-compensation measures. Technicians should go deep into the field to diagnose and identify the cause of the phytotoxicity and take remedial measures to reduce the phytotoxicity to minimize losses. In addition, research and cultivation of herbicide-tolerant crop varieties, the selection of varieties resistant to a herbicide as a change of cultivars, can also achieve the purpose of preventing or rescue phytotoxicity. Therefore, it is necessary to comprehensively consider various factors to prevent prevention.

Crop disease prevention

First, plant quarantine. The use of legal means to prevent the spread of diseases, insects and weeds along with plants and plant products, and strictly prohibit the transfer of seeds, seedlings and agricultural products with quarantine objects into protected areas. The demarcation or cancellation of epidemic areas and protected areas shall be submitted by the provincial or municipal agricultural authorities and reported to the government at the same level for approval.

Second, agricultural control. According to the relationship between pests, crops and environmental conditions, through the agricultural cultivation techniques, the farmland ecological environment is purposefully changed, which is beneficial to the growth of crops and is not conducive to the growth of harmful organisms, thereby avoiding or reducing pests and diseases. For example, it is possible to cultivate and utilize varieties with strong resistance, change cultivation methods, rationally adjust the layout of crop varieties, and try to strengthen field management. The agricultural control method is economical, simple, safe and effective. It requires the joint efforts of scientific research institutions and growers.

Third, biological control. A method of controlling harmful organisms by using beneficial organisms and their metabolites and gene products. Under natural conditions, there must be a certain number of natural enemies in the place where the persimmon pests exist. Under undisturbed ecological conditions, natural enemies often play an important role in controlling pests and diseases. We must try to protect and use the natural enemies of pests, develop beneficial organisms, and make appropriate use of some biological pesticides.

Fourth, physical and mechanical control. The former rural common scarecrow is now rare; it is both a scientific advancement and a regression of human civilization. There are many kinds of physical machinery, including optics, electricity, acoustics, mechanics, radiation physics, etc. However, the average rural growers are most suitable for the following types: equipment killing, such as armyworm nets, sticky insect boards, etc. Casting, such as lighting, sexual attractants, etc.; blocking, setting appropriate obstacles, preventing pests from spreading or spreading.

5. Chemical control. Chemical control is the use of pesticides to eliminate pests and diseases, quick results, high efficacy, no time or geographical restrictions, and therefore most friends love. However, the harmfulness of pesticides is also common, so how to limit pesticides is a big problem in the current planting industry.