1. Effects of Cultivation Management Techniques on Vegetable Quality
There are many kinds of vegetables in China, with short production cycle and complicated stubble times. In order to increase yield and control pests and diseases, it is necessary to apply chemical fertilizers, pesticides and plant growth regulators continuously. Whether fertilization is scientific and whether pesticides and plant growth regulators are safe are the key factors affecting vegetable quality.
1. 1 There are obvious misunderstandings in fertilization technology.
Most farmers lack knowledge of soil and fertilizer, so they seldom come into contact with new techniques of soil and fertilizer, especially in fertilization, which is blind and unscientific. This is mainly manifested in the following aspects: first, vegetable farmers can't use fertilizer varieties scientifically, relying on customary application and paying more attention to chemical fertilizers than organic fertilizers; Second, fertilization is not appropriate, but it is often excessive fertilization; Third, improper selection of application methods leads to the decline of fertilizer utilization rate. Unreasonable fertilization will pollute the environment on the one hand; Nitrogen and phosphorus loss will lead to eutrophication of surface water and deterioration of surface water quality; Nitrate nitrogen formed by nitrogen fertilizer will cause groundwater pollution; On the other hand, it causes the quality of vegetables to decline. Due to the large amount of fertilizer, harmful components in the fertilizer will accumulate in the soil, resulting in soil pollution. Contaminated soil products will turn harmful substances into vegetables, which will affect the quality of vegetable products.
1.2 The drug used for vegetable pest control is unsafe.
In recent years, through the investigation on the use of pesticides commonly used in main vegetable varieties in China, it is shown that the phenomenon of farmers abusing pesticides is still very common in the process of vegetable pest control. In the process of vegetable production, vegetable farmers lack rational drug use technology, and there are still many problems in the use of pesticides, which affect the quality of vegetables. First, in the process of pest control in vegetable production, they still use bad drug habits and high toxic and residual pesticides. Second, the concept of dose is vague, and patients with or without diseases use "insurance drugs", which cause environmental pollution in large doses; Third, the timing of medication is not allowed, and there is blind medication. Long-term unreasonable and excessive use of chemical pesticides in vegetable production leads to drug resistance of pests and pathogens. With the increase of drug resistance, vegetable producers are forced to increase the amount and frequency of pesticide use, and the pesticide concentration is increasing. At the same time, the use of high-residue pesticides and highly toxic pesticides is more and more extensive, resulting in higher and higher pesticide residues in vegetable products.
1.3 comprehensive pollution-free prevention and control technology has not been fully promoted.
The scattered planting of vegetables determines that the prevention and control of vegetable diseases and insect pests is basically carried out by one household, so it is difficult to fully popularize the comprehensive prevention and control technology of pollution-free vegetable diseases and insect pests in vegetable production. In order to effectively control agricultural pests and diseases, reduce pesticide pollution and improve vegetable quality, although agricultural technology extension agencies are also promoting the application of green pest control technologies such as insect traps, sex pheromones, frequency-vibrating insecticidal lamps and high-efficiency biological pesticides, the promotion of biological pesticides in vegetable production is not fast because of their high price and slow effect.
1.4 The residue of plant growth regulator is an invisible factor affecting the quality of vegetables.
In recent years, the problem of plant growth regulator residues is very prominent, but it has not attracted enough attention because of the lack of necessary management norms and testing standards. At present, it is very common to use plant hormones in vegetable cultivation. In the production of fruit vegetables such as cucumber, tomato, zucchini, eggplant and green pepper, in order to promote fruit setting, various growth regulators are often used to protect flowers and fruits. In order to promote fruit ripening and early listing, hormones are often used to accelerate ripening; Preservatives are often used to extend the shelf life of some vegetables during storage. Abuse of hormones and preservatives will pollute vegetable products and reduce their flavor and quality.
2. Countermeasures and suggestions to strengthen the quality and safety management of vegetable production in China
2. 1 Define the division of management and form a joint management force.
The quality and safety management of vegetable products involves many links, complicated situations and huge systems, which objectively requires unified management and organization. The agricultural product quality and safety management institutions in developed countries have their own characteristics, but they all have a common feature, that is, they all pay attention to the leading role of the agricultural authorities, and the whole process of management has a clear management subject and its division of labor, and the organization is very sound, with clear responsibilities and active cooperation. Therefore, in order to facilitate the popularization of safe vegetable production technology, China should strengthen cooperation in accordance with the requirements of the Agricultural Products Quality and Safety Law on the basis of clarifying the competent departments, form a joint management force, and implement the management of agricultural products quality and safety production.
2.2 Strengthen ecological environment protection and safe vegetable production and construction.
Strengthen the environmental management and protection of certified safe vegetable products. Actively guide the construction of safe vegetable production bases in some areas with good background ecological environment conditions, strong support from local governments and high enthusiasm of the masses for developing safe agricultural products; For production bases that have passed the certification of safe vegetable products, corresponding buffer zones or protection zones should be established according to the actual situation to prevent pollution to the producing areas and ensure the environmental quality of vegetable producing areas. At the same time, actively create conditions to gradually transform areas suitable for building safe vegetable production bases into safe vegetable production bases. In order to cut off the harm of harmful substances to the quality and safety of agricultural products from the producing environment and strengthen the source management of the quality and safety of vegetable products. Publish a paper.
2.3 Scientific and rational selection and use of pesticides
Rational selection of chemical pesticides. When diseases and insect pests are serious and physical and biological control measures can't be controlled, chemical control is still necessary. It has the advantages of high speed, good effect, time-saving and labor-saving, especially in the case of sudden pests and diseases, which is very popular among vegetable farmers. Therefore, it is impossible to cancel chemical pesticides to control vegetable diseases and insect pests at present or in the future. The key lies in how to scientifically select suitable pesticides with high efficiency, low toxicity and low residue according to different development stages and varieties of vegetable growth. If it is applied within a limited use range, the pesticide residue in vegetable products will not exceed the standard, and the product will not be polluted. Pesticides are used alternately. Foreign countries have long put forward the theory of alternate use of pesticides, and there are also research reports. Publish a paper. Alternating the use of pesticides with different action mechanisms can not only reduce the pollution of a single pesticide to the environment and the impact on non-target organisms, but also avoid the residue in vegetable products. In actual production, vegetable farmers are often reluctant to use other pesticides after using a certain pesticide with good effect, and use it many times a year or even for several years continuously. This phenomenon is more obvious in the use of organophosphorus pesticides. Because of the continuous use of the same pesticide, bacteria or pests develop drug resistance, which leads to the decline or even ineffectiveness of control effect. Therefore, pesticides with different mechanisms of action are used alternately, and one pesticide is only used 1-2 times in a production season, which delays the emergence of pest resistance, thus reducing the use of pesticides and reducing pesticide residues. Promote high-efficiency and low-toxicity alternative pesticide varieties and biological pesticides. The main reason why vegetable farmers are willing to use highly toxic pesticides is that their prices are relatively low and they have good control effects on some pests. To completely ban the use of highly toxic pesticides, it is necessary to choose varieties that can completely replace the banned highly toxic pesticides in terms of control effect and price. The application methods of pesticides include spraying, dusting, fumigation and root irrigation. Generally, under field conditions, the target part of spraying method is treated evenly, with large dose and good control effect. However, in the vegetable greenhouse, generally in autumn and winter, when the greenhouse is relatively closed, fumigation and powder spraying should be adopted. After April, with the temperature rising, the ventilation in the greenhouse increased, and spraying should be the main method. In order to control underground pests and soil-borne diseases, vegetables should be mixed with soil in advance before sowing, or seed coating method should be adopted. For local diseases and insect pests, local drugs such as stem coating and root irrigation can be used to minimize the use of pesticides in large areas. Fertilization should be balanced according to different growth stages of vegetables.
2.4 Strengthen the construction of safe agricultural products production technology extension system
The quality and technology application level of vegetable farmers largely determine the quality and safety level of vegetable products. Publish a paper. If the quality and scientific production level of vegetable farmers are not improved as soon as possible, even the best standards, norms and technologies will not be transformed into real productive forces, and promoting agricultural standardization and ensuring the quality and safety of vegetable products will also fail. Encourage and support agricultural technology popularization institutions at all levels, carry out quality and safety technical services for vegetable products, organize agricultural scientific and technological personnel to go deep into rural areas, extensively carry out quality and safety service guidance for vegetable products, promote standardized production, promote eco-safe vegetable production technologies and inputs, purify the environment of producing areas, strengthen source control, standardize production processes, strengthen production file management, and improve the quality and safety level of agricultural products production.
3. Conclusion
Production practice shows that the quality of vegetable products is controllable and closely related to farmers' income. Improving the quality of vegetables is the main channel to increase farmers' income. Ensuring the quality and safety of vegetables is the need of socio-economic and political development and the only way to build modern agriculture and new socialist countryside.
References:
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