costs for large programs. These compounds act by causing capillaries to break down,
resulting in internal bleeding, and by interfering with normal blood coagulation.
Some other rodenticides are sodium fiuoroacetate, fiuoracetamide, and a-naphthyl
thiourea (ANTU). The fiuoro compounds are highly toxic to other vertebrates as well
as to rats. A preferred rodenticide is diphacinone, also an anticoagulant and toxic to
other vertebrates, is used in tamper-resistant prebaited traps.
A contraceptive bait, called ContraPest, for fertility control of rats, has recently
been developed to reduce rat reproductive capacity in the management of
populations of Norway rats. This product has been approved for use in protecting
agricultural crops and reducing disease and requires further research [10].
Some other diseases transmitted to humans by vertebrate vectors are anthrax,
caused by the bacterium Bacillus anthracis and carried by livestock; psittacosis,
caused by a virus and carried by birds; and rabies also viral caused and carried by
dogs, cats, livestock, and many wild animals.
6 Pesticide Control of Organisms Destructive to Plants
Because humans can chemically modify the effects of climate, weather, and natural
predators on plant pests, the ability to produce large agricultural yields has been
greatly increased.
Of all plant parasites, fungi are the most numerous [11]. The taxonomic groups of
fungi with the largest number of plant pathogens are the fungi imperfecti and the
Ascomycetes. These organisms infect plants by (1) killing tissue prior to their spread
through the secretion of pectic enzymes producing soft rot and eventual death or
(2) feeding directly from the living plant cell without necessarily killing the plant
tissue.
Agricultural fungicides are applied to soil, seed, propagating material, and growing plants for combating fungal infections. The method of application and choice of
fungicide is specific for the particular plant. Agriculturalists have used dithiocarbamate fungicides and inorganic sulfur compound preparations widely and effectively
to control pathogenic fungi.
The guidelines for control of insects that are destructive or pathogenic to specific
plants are beyond the scope of this chapter. However, in brief, substantial losses both
during the growing season and in storage result from the action of insects on crops
and foodstuffs. Early synthetic insecticides were inorganic (Paris green,
silicofluoride, thiocyanates). The organic synthetic insecticide era has produced a
formidable array of chemicals with insecticidal (and often homicidal) properties.
Much of the search has been directed toward better insect selectivity, safety to higher
animals, and desirable levels of persistence.
As an example, fumigation with the pesticide phosphine gas is a critical tool to
assure protection of agricultural food commodities from spoilage. It is also an
intrinsically dangerous process: phosphine is deadly, flammable, and corrosive.
Failure to conduct fumigation properly poses serious risks to human health and of
400
L. S. Clesceri and E. J. Clesceri
resulting in internal bleeding, and by interfering with normal blood coagulation.
Some other rodenticides are sodium fiuoroacetate, fiuoracetamide, and a-naphthyl
thiourea (ANTU). The fiuoro compounds are highly toxic to other vertebrates as well
as to rats. A preferred rodenticide is diphacinone, also an anticoagulant and toxic to
other vertebrates, is used in tamper-resistant prebaited traps.
A contraceptive bait, called ContraPest, for fertility control of rats, has recently
been developed to reduce rat reproductive capacity in the management of
populations of Norway rats. This product has been approved for use in protecting
agricultural crops and reducing disease and requires further research [10].
Some other diseases transmitted to humans by vertebrate vectors are anthrax,
caused by the bacterium Bacillus anthracis and carried by livestock; psittacosis,
caused by a virus and carried by birds; and rabies also viral caused and carried by
dogs, cats, livestock, and many wild animals.
6 Pesticide Control of Organisms Destructive to Plants
Because humans can chemically modify the effects of climate, weather, and natural
predators on plant pests, the ability to produce large agricultural yields has been
greatly increased.
Of all plant parasites, fungi are the most numerous [11]. The taxonomic groups of
fungi with the largest number of plant pathogens are the fungi imperfecti and the
Ascomycetes. These organisms infect plants by (1) killing tissue prior to their spread
through the secretion of pectic enzymes producing soft rot and eventual death or
(2) feeding directly from the living plant cell without necessarily killing the plant
tissue.
Agricultural fungicides are applied to soil, seed, propagating material, and growing plants for combating fungal infections. The method of application and choice of
fungicide is specific for the particular plant. Agriculturalists have used dithiocarbamate fungicides and inorganic sulfur compound preparations widely and effectively
to control pathogenic fungi.
The guidelines for control of insects that are destructive or pathogenic to specific
plants are beyond the scope of this chapter. However, in brief, substantial losses both
during the growing season and in storage result from the action of insects on crops
and foodstuffs. Early synthetic insecticides were inorganic (Paris green,
silicofluoride, thiocyanates). The organic synthetic insecticide era has produced a
formidable array of chemicals with insecticidal (and often homicidal) properties.
Much of the search has been directed toward better insect selectivity, safety to higher
animals, and desirable levels of persistence.
As an example, fumigation with the pesticide phosphine gas is a critical tool to
assure protection of agricultural food commodities from spoilage. It is also an
intrinsically dangerous process: phosphine is deadly, flammable, and corrosive.
Failure to conduct fumigation properly poses serious risks to human health and of
400
L. S. Clesceri and E. J. Clesceri