Plants Protection from unfavorable conditions of the Earth by Different means created by the Humans with the help of Nature

plants protectionPlant protection

Plant protection is the science and practice of managing invertebrate pests and vertebrate pests, plant diseases, weeds and other pest organisms that damage agricultural crops and forestry.

Plants and crops should be protected by different means

  • biological means
  • physical means
  • chemical means
  • quarantine means
  • integrated management
  • cultural means

Crops should be protected from these …….

  • Diseases which should cause by these agents
  • Bacteria
  • Fungi
  • Virus
  • Nematode
  • Insects
  • Weeds
  • Biological stress
  • Environmental factors
  • Temperature
  • Frost
  • Drought
  • Edaphic factors
  • Salinity and alkalinity
  • water logging
  • hard pan

Protection of plants or crops from diseases which is caused by the bacteria, fungi, virus and nematode.

Biological control

Bio fungicides

Bio fungicides are commercial products that are composed of beneficial organisms such as fungi, bacteria, or actinomycetes that suppress plant diseases.

Predators and parasites (hyper parasites)


Predators are generally non-specific natural enemies which eat many preys.  Mites, springtails, protozoans, free-living nematodes and earthworms in soil feed on disease organisms and may contribute to their biological suppression.

Parasitism, hyper parasitism

Antagonistic fungi may parasitize fungal disease organisms by directly penetrating the host hyphae and killing them


A bacteriophage is a virus that can infect a bacterial cell and cause the host cell to break down.

Physical control

Bio Clays

The Australian Institute for Bioengineering and Nanotechnology at the University of old is researching Bio Clays to manage field and postharvest diseases.

Quarantine measure


Biosecurity is more than just preventing incursions of exotic pests, diseases and weeds.

Biosecurity is the protection of the economy, environment and human health from the negative impacts associated with entry, establishment or spread of exotic pests (including weeds) and diseases (Beale et al 2008).

Cultural means

  • Cultural methods are mostly preventative and are compatible with other control methods.
  • Practices should favor crop growth but not pests, disease or weeds.
  • Symptoms caused by incorrect cultural practices are often difficult to recognize.

Resistant variety

The best solution to any plant problem is to use resistant or tolerant varieties of plants if available it is a preventative method of control (Aust. Hort. Feb 2011).

Crop rotation

Crop rotation very beneficial to overcome the plant diseases because there is no host plant should available for to complete the life cycle.

Integrated diseased management

Disease control in ornamentals can be difficult for several reasons, many ornamentals are vegetative propagated and so more prone to disease infestations than sexually propagated materials. Vegetative propagated material has greater Uniformity with a potentially greater severity of disease.

Note that the effectiveness of a Fungicide increases when the inoculum potential decreases. Sometimes management practices like recirculate water can increase the frequency of Phytophthora and Pythium.

Chemical control

A good quality of fungicide and the chemical should be used in a proper time and quantity on the proper time.

Plant protection with respect to insect

Cultural method

Different type of cultural methods should be used to protect the plants from insects.

  • Crop rotation should be done.
  • Resistant variety should be selected.
  • Remove the susceptible host like the weeds.
  • Remove the diseased plants.
  • Destroy the eggs colonies of insect through using the different tillage operations.
  • Use the proper irrigation and fertilizer according to the requirement of the plant and recommendation.
  • Destroyed of all the stubbles of infested plants.
  • Provide the proper sanitation condition.

Physical means

  • Use the different kind of equipment to capture the insects.
  • Use the specific type of chemical which is called pheromones to attract the female and male.
  • Use special type of light to attract and repel the insects.
  • Use the gum plastic sheet,

Biological method

Traditionally, biological control of insects and mites has been brought about by other insects and mites and by disease organisms. Because biological control is part of the phenomenon of natural control, the number of aphids on roses at any one time can be controlled naturally by at least 10 insects, several diseases, the weather, availability of food, and other factors.


  • Predatory insects, mites and spiders attack and eat other insects or mite prey. Predatory ladybirds, other beetles and lacewings feed on their prey by chewing. Predatory bugs and mites suck juices
  • From their hosts. Either adults or larvae or both may be predatory.  Some predators supplement their diet with pollen, nectar and fungi. Predators are usually more robust than parasites.
  • Ladybird beetles devour more aphids when aphids are abundant then when
  • Aphids are scarce


  • Parasitoids lay eggs on or in other insects .The eggs hatch and the developing larvae feed on the host.
  • The most common parasitoid insects are wasps and flies.
  • Each species of parasitoid attacks a certain stage of its host’s life cycle.

Chemical control

  • Use the insecticide to control the insect.
  • Use the proper chemical according to the requirement keeping the view of economical threshold level.

Plant protection with respect to weed

  • Weeds affect the plant in numerous ways from germination to harvesting.
  • Usually it affects more in the early stages than late stages.
  • Weeds should compete for nutrition, water and space, light.
  • Cultural method
  • Growing the crops through the proper crop  rotation principles.
  • Tillage operation should be used.
  • Line to line and plant to plant distance should be according to the recommendation.
  • Manage the seed rate and plant population.
  • Proper use of irrigation and fertilizer,

Physical methods

  • Remove the weeds with the equipment’s,
  • Hand tool should be used.

Biological method

By releasing natural enemy

Classical biological control is the most common way to bio control weeds and is achieved by the release of insects, mites, rusts and other organisms into a region to permanently suppress targeted weeds.  The aim is to establish a natural balance between the weed and its control agent – similar to the balance found in the native range of the weed.

Bio herbicides

Bio herbicides are fungi, bacteria and other microorganisms that cause plant diseases that often result in death or reduced weed vigor.

Allelopathy Allopathic-chemicals have potential as bio herbicides

Allelopathy refers to the beneficial or harmful effects of one plant on another plant, both crop and weed species, by the release of chemicals from plant parts, by leaching, root exudation, volatilization, residue decomposition and other processes. It occurs in both natural and agricultural systems and provides a means for developing new herbicides (Ferguson and Rathinasabapathi 2009)

Alligator weed

Alligator weed flea beetle (Agasicles hygrophila) controls the aquatic form of alligator weed.

Contraceptive for weeds

Scientists aim to trick weeds into shutting down their reproductive system by fooling them into thinking they are having sex with themselves. The project hopes to mimic in the laboratory the chemistry that most plants use to spot and reject their own pollen to avoid inbreeding.  When sprayed on weeds it would act as a contraceptive, confusing them into thinking they are being self-fertilized (Macey 2005)

Chemical control

Use the proper weedicide to protect the plant from weeds.

Plant protection with respect to environmental factors


When the temperature goes to low than before to the lowing the temperature in the environment, the plant start to enhance the conc. in the cell which protect it from ice crystals.


In the drought condition anti transparent a chemical should be used.


There are several ways of controlling frost, including: Passive designs, e g planting dates. Growing in frost-free locations is not always possible in areas where heavy frost occurs.

Either select frost tolerant species for growing during the colder months and locate frost-sensitive plants in frost-free sites, or have in place steps to minimize frost risk.

Frost-prone areas are generally sown last to help avoid the high-risk period.  Wind machines raise and maintain temperatures by drawing warm air down from above the inversion layer that exists at times of radiant frost conditions in vineyards.

Clean cultivated soil, rolled and irrigated will retain heat during periods of frost. This source of heat could be utilized as part of a vineyard frost control program.

Wind breaks should be properly maintained during frost threats, e g thinned to allow cold air to pass through. Improperly maintained windbreaks can add to frost and freeze risk. Spraying with water, overhead or flood irrigation etc.  Many plants are frost tender, particularly when young.  During mild frosts (-1 -2oC) an irrigation system (if set up properly) can reduce their severity and often eliminate any damage within an orchard. The principle behind using a standard irrigation system is that the temperature of water, by nature is more than 0oC; therefore by turning on the irrigation, the temperature around your trees will be kept above freezing point (McCarthy 2001).


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Ferguson, J. J. and Rathinasabapathi, B. 2003 (reviewed

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Case study GRDC Growers’ Report 2008-2009.

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International Atomic Energy Agency, Vienna, 2002 Dosimetry for Food Irradiation. Technical Reports Series no. 409.

Griggs, P. 2008. Defeating Cane Diseases: Plant Pathologists and Development of Disease Control Strategies in the Australian Sugar Industry, 1920-1950. CSIRO Pub. Guenther, L. 2013. The Future of Weed Control. GrainNews 39, (9).

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Muhamamd Zunair Latif*,Imran Ramzan1, Arslan Shehroz2, and Asrar Masood3.

Author * Department of Plant pathology, University of Agriculture Faisalabad

Co- Author1&2 Department of Agronomy, University of Agriculture Faisalabad,

Department of Plant pathology, University of Agriculture Faisalabad

3Department of Soil and Environmental Sciences, University of Agriculture Faisalabad

E-mail: [email protected]


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