At present, the main causes of vegetable pollution are improper use of pesticides , unreasonable use of chemical fertilizers and environmental pollution. Because vegetables are mostly used for fresh and tender tissue for human consumption, these tissues are also vulnerable to pests and diseases. Sometimes, during the harvesting period, it is necessary to apply pesticides for prevention and control, and to carry out "worms to seize vegetables", it is necessary to effectively control pests and diseases, but also It is especially important to choose pesticides to ensure the safety of human food.
First of all, you should choose a biological pesticide or biochemical preparation that has good effects and is not toxic or extremely toxic to humans, animals and natural enemies. For example: Bt preparation has good control effect on cabbage caterpillar and diamondback moth. Such preparations are eaten into the stomach by the worms, and under alkaline conditions, the toxicity is caused to cause the insects to die. Human and animal stomach are acidic, Bt toxicity can not be exerted, and it is safe for humans and animals. Biochemical preparations refer to agricultural antibiotics, such as streptomycin and penicillin, which can be used by the human body. It is of course safe to use on vegetables.
The second is to select specific insect growth regulators , such as chlorbenzuron, Nongmute, Youle, and Taibao. The insecticidal mechanism of this kind of chemical pesticide is to inhibit the growth and development of insects, so that it can not be peeled and ageed, and its insecticidal activity. Very high, very low toxicity to humans and animals.
The third is to choose high-efficiency, low-toxic and low-residue pesticide The normal use of such pesticides will not cause poisoning accidents and is safer.
The fourth is to select the medium-toxic and low-residue pesticides with good efficacy. There are many kinds of vegetable pests and diseases, which are serious, especially some disaster-causing pests and diseases. If they are improperly controlled or not timely, they will cause devastating losses. The biological agents and specific functional remote preparations have few varieties, strong professionalism, limited opportunities for selection, and the quick-acting properties of such pesticides are slightly poor. Medium-toxic pesticides can be used in cases where low-toxic, low-residue pesticides cannot control pests and diseases. It is necessary to pay attention to the application of such pesticides. First, according to the safe use of pesticides; second, to select agents with lower toxicity, it is safer to choose pesticides with LD50 over 100 or above.
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