TNPSC Free Notes Chemistry – Fertilizers and Pesticides

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

Fertilizers and Pesticides

Nutrient Management
Macro Nutrients
 Elements which are needed in large quantities for growth of the plants are called Macro
Nutrients

 C, H, O, N, P, K, S, Ca, Mg, Fe
Micro Nutrients
 Elements which are needed by the plants in very small quantities are called Micro
Nutrients.
 Mn, Cu, Mo, Zn, B, Cl
Manure
 Organic Substance
 Decomposition of Plants & Animals
Classification of Manure
 Compost & Vermi Compost
 Compost prepared by using earth worms to speed up the process of decomposition of
plant and animal wastes is called Vermi Compost

Green Manure
 Using Leguminous plants like sunhemp & Soyabean
 N & P Nutrient
Uses of Manure
 Enhances – Water Holding Capacity
 Increase – Friendly Microbes
 Improves – Soil Textures
Fertilizers
 Inorganic Substance
 Commercially produced
Types of Fertilizers
Nitrogenous Fertilizers

 Urea
 Ammonium Sulphate
 Ammonium Nitrate
Phosphatic Fertilizers
 Single Super Phosphate
 Triple Super Phosphate
Potassic Fertilizers
 Potassium Nitrate
 Potassium Chloride
Complex Fertilizers
 Nitro Phosphate
 Ammonium Phosphate
 Diammonium Phosphate [DAP]
Disadvantages in Fertilizers
 Expensive for Farmers
 Contaminate Natural water drainage
 Eutrophication (Algae)
Eutrophication
 Excessive richness
 Dense Algae Growth (Surface)
 Death of other organisms

Fertilizers and Pesticides
Pest Control
There are different methods of controlling of the pests. The mostcommon method of
controlling pests is the use of pesticides.
Classification of Pesticides
Pesticides are classified as Insecticides, Fungicides, Weedicides, Rodenticides, etc., depending
upon their use.
Insecticides
 The chemical substances which are used to kill the insects are called insecticides.
 e.g. DDT (Dichloro diphenyl trichloro ethane), Malathion etc.,
Fungicides
 The chemicals used to kill fungi are called fungicides.
 e.g. Bordeaux mixture.
Weedicides

 The chemical substances which are used to kill the weeds are called weedicides.
 e.g.2-4-D (2-4-Dichloro phenoxy acetic acid)
Rodenticides
 The chemicals used to kill rodents like rats, mice and squirrel are called rodenticides,
 e.g. Zinc Phosphate, Arsenic etc.
Insect pests
 Insects are serious pests of plants which attack them in all stages and parts.
 Based on the mode of attack, the insect pests can be classified into three types.
Chewing Insects
 They cut and chew the root, stem and leaves of the plants.
 e.g. grasshoppers, caterpillars, etc.

Sucking Insects
 They suck the cell sap from different parts of the plants.
 e.g. Leaf hoppers, aphids etc.,
Borer Insects
 They bore and enter different parts and feed on the plant tissues.
 e.g. sugarcane borer
Methods of insect Pest control
 The infestation of different types of insect pests can be controlled by the following
methods.
 Root cutting insects are controlled by mixing insecticides in soil.
 e.g. Chloropyriphos.
 Stem and leaf cutting and boring insects are controlled by dusting or spraying contact
insecticides. e.g. Malathion, Lindane and Thiodan.
 The sap sucking insects can be controlled by spraying insecticides. e.g. Dimethoate and
Metasystox.
Bio-Fertilizers
 Blue Green Algae (Cyanobacteria)
 Oscillatoria

 Anabaena
 Nostoc
 Aulosira
 Calothrix
 Gleocapsa
 Scytonema
 Azolla
 Mycorrhiza
 Rhizobium
 Azospirillium
 Azotobacter

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