Kaolin spray is a
pest control
Pest control is the regulation or management of a species defined as a pest (organism), pest; such as any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the da ...
that has
kaolin
Kaolinite ( ; also called kaolin) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral sheet of alumina (). ...
as the main ingredient. The practice has been in recorded use from 2000 B.C.E. in China. More recent studies have shown that kaolin sprays can promote photosynthesis and are effective in reducing insects and disease on plants.
Description
Kaolin is a rock rich with the clay mineral
kaolinite
Kaolinite ( ; also called kaolin) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral sheet of alumina () ...
. Kaolin spray is a
pest control
Pest control is the regulation or management of a species defined as a pest (organism), pest; such as any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the da ...
that has kaolin as the main ingredient.
History
In nature, many animal species commonly take "
dust baths" to rid themselves of
insect
Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
parasites and prevent attacks from biting insects. In 2000 B.C.E., records in China describe the application of mineral-based dusts (e.g.,
diatomaceous earth
Diatomaceous earth ( ), also known as diatomite ( ), celite, or kieselguhr, is a naturally occurring, soft, siliceous rock, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging fr ...
) to plants to control insects. Subsequently, various mineral-based preparations have been used, and some of these remain in use for agricultural
pest control
Pest control is the regulation or management of a species defined as a pest (organism), pest; such as any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the da ...
.
More recently, kaolin mixed with spreaders and stickers and applied to plants as a spray at 1–6% concentration in water form has been shown to be an effective approach to agricultural pest control and to protect plants from
environmental stresses. Kaolin-based sprays have been studied extensively since 1999 and research has established that these sprays deposit a "particle film" that has numerous beneficial effects on plants and in insect pest control. Certain kaolin-based sprays can form a highly reflective white film over plant surfaces that enhances plant
photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...
and reduce heat stress in plants, which they do by reflecting the
infra-red light
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those o ...
spectrum, which in improves plant yields and fruit quality in orchards. The kaolin barrier created by the particle film also protects the treated plant surfaces from
diseases
A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...
, and insects.
[Puterka, G. J., D. M. Glenn, and R. Pluta. Action of particle films on the biology and behavior of pear psylla (Psyllidae: Homoptera). J. Econ. Entomol. 98: 2079-2088. 2005.]
See also
*
Medicinal clay
The use of medicinal clay in folk medicine goes back to prehistoric times. Indigenous peoples around the world still use clay widely. Such uses include external application to the skin and geophagy. The first recorded use of medicinal clay goes ...
*
Mechanical pest control Mechanical pest control is the management and control of pests using physical means such as fences, barriers or electronic wires. It includes also weeding and change of temperature to control pests. Many farmers at the moment are trying to find su ...
References
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Pest control techniques