Tobacco scientific use of pesticides

Pesticides on the development of human civilization, agriculture has played an important role, especially in controlling risk , when the outbreak of pests and diseases , pesticides also show an irreplaceable role . However, in the course of pesticides on the air, soil and water will cause a certain degree of pollution, which requires scientific use of pesticides, with the least amount of the most effective pest control for maximum economic, social , ecological and environmental benefits.

In view of the status of tobacco production ,plastic sprayer  the State Tobacco Monopoly Bureau, Science and Technology Education proposed the development of "pollution-free tobacco " new ideas, relying on science and technology can make use of the use of pesticides near or at the effects of pollution . Despite the development of biological pesticides now in full swing, but it is widely used in the tobacco need to take time .

1 associated with the spraying of pesticides technical parameters

1.1 LD50 (ld50)

LD50 is the result of a biological experiment death of the individual populations of 50% of the dose. According to China Pesticide Toxicology grading standards , rat oral : ld50 <5mg/kg are highly toxic pesticides, such as " aldicarb " original drug ld50 of 1.0mg / kg; ld50 is 5 ~ 50mg/kg is a highly toxic pesticides such as " omethoate " original drug ld50 is 47mg/kg; ld50 of 50 ~ 500mg/kg belong moderately toxic pesticides, such as " fenvalerate " original drug ld50 is 451mg/kg; ld50> 500mg/kg belong toxicity pesticides, such as "In addition to bud through" the original drug ld50 of 1250mg / kg; ld50> 2000mg/kg are practically non toxic pesticides, such as pest control tobacco warehouse "insurable special" original drug ld50 is 34600mg/kg. ld50 reflect pesticides on the environment or the degree of harm to humans and animals by improving the formulation processing technology, can achieve low toxicity of highly toxic pesticides , toxic pesticide poisoning micro . weed sprayer Such as " decis " the active ingredient is " deltamethrin ", " deltamethrin " original drug ld50 is 138.7mg/kg, belonging to moderately toxic , processed into 2.5% EC ( " decis " ) after , ld50 is 535mg/kg, belonging to low toxicity pesticides. " Aldicarb " original drug is very poisonous, but commonly used to control aphids Tobacco 15% "iron aldicarb " granules (ld50 is 10.6mg/kg) is highly toxic .

1.2 Half-life (dt1 / 2)

Pesticide degradation half-life is a measure of the degree of difficulty of the targets. It reflects the pesticide sustained effect on pest control and pesticide residues levels. Long half-life of the pesticide persistence length to pests and diseases , can in a very long time to maintain the role of harmful organisms performance, but it is also the source of pesticide residue formation . dt1 / 2 <3 months of easily degradable pesticides ; dt1 / 2 of 3 to 12 months for the middle of pesticide residues ; dt1 / 2> 12 months for the long pesticide residues. Early use of arsenic , lead and mercury preparations half-life of 10 to 30 years ; half-life of organochlorine pesticides in 2 to 4 years , the half-life of organophosphorus pesticides are generally a few weeks to a few months ( " phoxim " the half-life in soil is 34d),water sprayer  carbamate pesticides generally only a half-life of ~ 4 weeks ( " aldicarb " In the half-life of fresh tobacco 14.4d), pyrethroids , sprouting products and herbicides half-life of a few days ( " deltamethrin " In the half-life of fresh tobacco 2.1 ~ 4.2d; " in addition to bud through" in the half-life of fresh tobacco 2 ~ 4d; Napropamide in the half-life of fresh tobacco 3 ~ 4d).