Plant protection by chemical means

1. PLANT PROTECTION
CHEMICAL METHODS

2. CHEMICAL MEANS OF PLANT PROTECTION
A variety of chemicals are available that have been designed to control plant
diseases by inhibiting the growth or by killing the disease-causing pathogens .
Chemicals used to control bacteria , fungi and nematodes may be applied to
seeds , flowers ,fruit and soil. They prevent or reduce infections by utilizing
various principles of disease control .

3. CLASSIFICATION OF PESTICIDES
Sphere of activity (based on usefulness)
•Insecticides : used to control insects, eg : carbofuron
•Fungicides : used to control fungal disease in plants,
eg : menab
•Herbicides : used to control weeds , eg :MCPA
•Nematicides : used to control nematodes ,
eg : phenamiphos

4. Mode of action
• Contact poison : the action of these chemicals follows the action
between the contact of the body of the insect and the insecticides
eg : carbaryl
• Systemic poison : these chemicals move within the plant tissues
and toxicity to sucking insects feeding on plant sap eg :
carbofuran
• Fumigants : acts by its vapour action
eg : methyl bromide

5. Based on disease control
• Protectant chemicals : It creates a barrier between plant and pest/pathogen.
• Eradicant chemicals : Remove the pathogen from infection court.
• Chemotherapeutants: Applied to combat an infection in progress.

6. TYPES OF PESTICIDE FORMATION
• Dusts
• Granules
• Emulsifiable concentrate (EC)
• Flowables
• Wettable powders
• Poisonous baits

7. METHODS OF APPLICATION
• The success of a pesticide application depends on the pesticide and proper
application . Improperly applied pesticides can result in ineffective control,
plant injury or excessive pesticide residues. Maximum coverage of the target
area is essential to the control of plant pests . Pesticides are a major part of
most crop budgets . Every effort should be made to insure that applications
are correct and safe.
• Spraying (https://aggie-horticulture.tamu.edu/vegetable/guides/texas-
vegetable-growers-handbook/chapter-ix-chemical-application-and-safety/)
• Dusting
• Fumigation

8. MERITS OF CHEMICAL PROTECTION
• Cost effectiveness
• Timeliness and flexibility
• Quality , quantity and price of produce
• Prevention of problems

9. DEMERITS OF CHEMICAL PROTECTION
• Reduction of beneficial species. Non-targets organisms, including predators
and parasites of pest.
• Drift of sprays and vapours during application can cause severe damage and
residue problems in crops .
• Ground water contamination by leached chemicals.
• Residues in food for humans and feed for livestock.
• Resistance to the pesticide used can develop in target pests due to overuse
and incorrect use of the chemical.
• Poisoning hazards and other health effects.

10. THANKYOU