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The prediction of crop pests and diseases can be divided into short-, medium-, and long-term predictions according to the length of the prediction period. They are generally bounded by ten days, months (quarters) and years, respectively. Forecasts for several years can be called ultra-long-term predictions. In past plant protection work, short-term and medium-term predictions have achieved great results; however, this prediction mainly serves the prevention and control of chemical agents, and is also an emergency measure for the palliative treatment. At present, the comprehensive prevention and control of diseases and pests must meet the needs of sustainable agricultural development and cannot rely solely on chemical prevention and control.
It is well-known that the interaction and co-evolution of pathogens and host populations is the main mechanism for disease epidemic. The rational use of plant disease resistance is often the primary measure of disease management; if the agricultural control seems to be normal, if it takes ten years or even decades, its effects (including good and bad) are obvious; biological control, such as the release of natural enemies It may be a short-term effect. Once biological control can play a role in maintaining an ecological balance, the effect is long-term. The above three kinds of control measures have naturally risen in the status of continuous plant protection, and the adoption of these measures urgently requires long-term and ultra-long-term predictions. Obviously, only when wheat rust is expected to occur in the coming year before wheat is planted, and new dominant species will appear in the strain, it is possible to replace the disease-resistant variety.
The basis for the ultra-long-term prediction, in addition to the biological characteristics of various pests and diseases, is mainly the cyclical climate change, farming systems, and changes in cultivation methods. When we have not yet recognized some natural laws or neglected some natural laws, subjectively undergoing large-scale transformation of the agricultural ecosystem, it often leads to major pest and disease disasters. Conversely, when we predict that the cultivation of a single crop or variety, large-scale cultivation of crops, large-scale spraying of a pesticide, or addition of a stimulation measure may contribute to the extreme increase in the number of pest populations, it is possible to evade the wrong decision. Or take other remedial measures at the same time to offset its adverse effects. This may be the fundamental way to continue to control the epidemic of diseases and insect pests, and it is a fundamental solution to the problem.
Author: Xiao Yue Yan (The author is a senior consultant Sinochem fertilizer, China Agricultural University)
Long-term forecast of pests and diseases needs to be strengthened
As the saying goes: Everything is presupposed, but it is not abandoned. The same applies to pest control. In the late 1980s, wheat scab was found in northern China. Because the disease had previously only occurred in the middle and lower reaches of the Yangtze River, northern wheat growing areas did not carry out prediction work on the disease, nor did it prevent and control. In 1989, Henan alone lost 885 million kilograms of wheat. In the second year of state funding, prevention and control of head blight was organized and implemented. However, the disease was not actually popular. In the two years before and after, the cost of illness caused by illness and the cost of fighting drugs were all losses because the forecasting work was not done.