CEP 510 Course Note PDF

**Course Note** **CEP 510: Biological Activity of Pesticides** **(Part I)** **Chris O. ECHE, PhD, FISDS** **^1^Department of Crop and Environmental Protection** **^2^Department of Environmental Sustainability** **^3^Center for Innovation in Procurement, Environmental and Social Standards** **...

**Course Note** **CEP 510: Biological Activity of Pesticides** **(Part I)** **Chris O. ECHE, PhD, FISDS** **^1^Department of Crop and Environmental Protection** **^2^Department of Environmental Sustainability** **^3^Center for Innovation in Procurement, Environmental and Social Standards** **Joseph Sarwuan Tarka University, Makurdi** [**ceche\@uam.edu.ng**](mailto:[email protected]) **+234 803 828 8040** **Session I:** **Introduction: Definitions & Concepts** 1. **Definition of pesticides** 1. Use or target pests 2. Mode of Action 3. Toxicity 4. Chemistry/Chemical structure 2. Classification of Pesticides ---------------------------- 1. ### Classification based on Use or target Pests: a. **Acaricides:** The substances that are used to kill mites and ticks, or to disrupt their growth or development. Eg: DDT, dicofol, Fenpyroximate b. **Antifeedants:** The chemicals which prevent an insect or other pest from feeding. Eg: Chlordimeforn, Fentin and Azadirachtin. c. **Bactericides:** The compounds which are used to kill or inhibit bacteria in plants or soil. Eg: Copper hydroxide, Kasugamycin, Streptomycin, Tetracycline, etc d. **Fungicides:** The chemicals which are used to prevent, inhibit or eradicate fungi. Eg: carbendazim, thiabendazole, thiophanate-methyl, etc. e. **Chemosterillant:** The chemicals that renders an insect infertile and thus prevents it from reproducing. The chemosterillant acts by inhibiting the production of egg, causes death of the eggs or cause lethal mutation on the spam or eggs material Eg: Aziridinyl, Diflubenzuron, etc. f. **Herbicides:** Substances that are used to kill plants (mostly weeds) or to inhibit their growth or development. Eg: Paraquat, Glyphosate, 2,4-D, etc. g. **Insecticides:** A pesticide that is used to kill insects, or to disrupt their growth or development. Eg: Monocrotophos, Carbofuran, Lambdacyhalothrin h. **Nematicides:** The chemicals which are used to control nematodes. Eg: Abamectin, 2. **Rodenticides:** The substances used to kill rats and related animals. Eg: Zinc Phosphide, Bromadiolane, etc.Classification based on Mode of Action: ### Contact pesticides: ### Stomach pesticides: ### Systemic pesticides: ### Translaminar: ### Fumigant: ### 1.2. 3. Classification based on Toxicity: -- -- -- -- -- -- -- -- -- -- ### 1.2.4. Classification based on Chemistry/Chemical structure: 2. Insecticides ============ 1. Introduction: ------------- 1. **Natural Organics:** The natural organic pesticides are derived from naturally occurring sources such as plants, microorganisms etc. and may be divided as Microbial bio-pesticides and Botanical Pesticide. Microbes used as bio-pesticides are basically bacteria (Antagonistic and Entomotoxic Bacteria), fungi (Antagonistic and Entomopathogenic Fungi) and viruses (Nuclear polyhydral virus and Baculovirus). Two major botanical pesticides are Azadirachtin and Pyrethrin. 2. **Synthetic organic pesticides** are produced artificially by chemical synthesis. This group comprises most \"modern\" pesticides and subdivided into following groups: i. Organochlorine Pesticides ii. Organophosphate Pesticides iii. Carbamates iv. Synthetic-pyrethroid v. Other Insecticides #### Chlorinated Hydrocarbon: -- -- -- -- **ii. Organophosphorus Insecticides:**  -- -- -- -- -- -- #### Carbamates: #### Pyrethroids: #### Oher Insecticides: a. ***Neonicotinoids insecticides**:* Neonicotinoids are a new class of insecticides with nicotinic receptor agonist. The neonicotinoid insecticides include imidacloprid, acetamiprid, nitenpyran, dinotefuran, thiamethoxam, thiacloprid and clothianidin. Among these, imidacloprid is most widely used at present. b. **Insect Growth Regulators:** Juvenile hormone analogs and mimics when applied to an insect, an abnormally high level of juvenilizing agent will produce another larval stage or produce larval-pupal intermediates. Juvenoid IGRs can also act on eggs, can cause sterilization, disrupt behavior and disrupt diapauses. Anti-juvenile hormone agents cancel the effect of juvenile hormone, an early instar treated with an anti-juvenile hormone molts prematurely into a nonfunctional adult. Some of the examples are methoprene, kinoprene, hydroprene, pyreproxyfen, fenoxycarb etc. Some examples for ecdysteroids include compunds namely tebufenozide (MIMIC, CONFIRM) halofenozide, methoxyfenozide, chromafenozide, difenolan etc. c. **Chitin synthesis inhibitors:** These are chemically diverse compounds that affect reproduction and development of chitin synthesizing organisms (insect and fungi) to varying degrees. Application of chitin synthesis inhibitors typically induces malformations of the cuticle and a significant reduction of chitin amounts. Ex. diflubenzuron, triflumuron, hexaflumuron, novaluron, lufenuron, flufenxuron, teflubenzuron, chlorfluazuron, etoxazole, hexythiazox, clofentazine and buprofezin. d. **Avermectins:** e. **Spinosyns:** Spinosyns are the group of compounds was originally isolated from *Saccharopolyspora spinosa* (actinomycetes). Spinosad is a mixture of at least two major compounds, spinosyn A and spinosyn D, in which spinosyn A is a major constituent. These effects are consistent with the activation of nicotinic acetylcholine receptors by a mechanism. Spinosad is approved for use as an organic insecticide for caterpillars, leaf miners, thrips and foliage-feeding beetle. f. **Botanical Insecticides:** Botanical pesticides, in the form of isolated substances or complex mixtures, exhibit a range of biological activities, acting as insecticides, [repellents](https://www.sciencedirect.com/topics/earth-and-planetary-sciences/repellent), attractants, [fungicides,](https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/fungicide) [nematicides,](https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/nematicide) and [bactericides](https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/bactericide). It has been reported that about 17500 aromatic plant species growing worldwide in tropical environments and more than 3000 constituents have been identified to possess significant pesticidal properties. g. **Microbial Insecticides:**Different species and strains and *Bacillus* bacteria are known to affect different groups of insect pests, primarily due to differences in endotoxin receptor sites on the gut wall. The lethal component is crystals of δ-endotoxin. *Bacillus thuringiensis* var. *kurstaki* (Dipel, Javelin) is effective against caterpillars of moths and butterflies -- -- -- -- -- -- 3. Fungicides ============= Introduction: ------------- ### Based on the time of application: ### 3.1.2 Based on their movement ### 3.1.3. Based on Use*:* A. *Foliar-Applied Fungicides***:** B. *Seed Treatment Fungicides* +-----------------------+-----------------------+-----------------------+ | | **Fungicide** | **Controlling | | | | pathogen** | +=======================+=======================+=======================+ | | Glyodin,Fenopanil | *Ascomycetes spp.* | | | Prochloraz, Imazalil | Basidiomycetes, | | | | | | | | *Helminthosporiumsp,F | | | | usarium* | | | | and | | | | | | | | *Septoria* spp | +-----------------------+-----------------------+-----------------------+ | | Carbendazim,Benomyl | *Erysiphe, | | | Cypendazole,thiophana | Septoriu*and | | | temethyl | *Fusarium* sp. | | | | | | | | *Deuferomycete* | +-----------------------+-----------------------+-----------------------+ | | Fluotrimazole,Triadim | Powdery mildew and | | | efon | Rust | | | Triadimenol, | | | | Bibertanol | *Ustilagonuda*, *U. | | | | tritici, U. maydis | | | Diclobutrazol,Triazbu | Venturia*sp. | | | til | | +-----------------------+-----------------------+-----------------------+ 4.1 Introduction: ----------------- 4.2. Herbicides are also classified based on the mode of action: ---------------------------------------------------------------- 2. ***6.* Seedling growth inhibitor:** Interrupt new plant growth and development. Grass shoots are short and thick and may appear red or purple in colour. Example: ***Butachlor*** 4.3. Plant growth regulator (PGR): ---------------------------------- ### 1. Auxin: ### Cell Elongation: ### Root Initiation in stem cuttings: ### Apical Dominance: ### 2. Gibberellins: #### Functions of Gibberellins: a. Stimulate stem growth through cell elongation and cell division. b. Involved in overcoming dormancy in seeds and buds. c. It causes internodes to stretch in relation to light intensity. d. Used commercially in stimulating seed germination & seedling growth e. Stimulate development of flowers. Delayed ripening Flowering Malting f. Increasing fruit size of seedless (Parthenocarpy) in grape g. Delay Senesence: Increase photosynthesis and proteins synthesis and thereby decrease abscission h. Increase cambial growth and differentiation i. Break dormancy and promote leaf expansion. ### 3. Cytokinins: ### Functions of Cytokinins: a. Cytokinins promote cell division (Cytokinesis) b. Contribute to cell elongation in leaves c. Stimulate cell differentiation in combination with auxins. ### 4.3. 4. Ethylene: ### Functions of Ethylene in Plants: a. Inhibits root and shoot initiation by blocking the transport of auxins from apical meristems and controls stem elongation. b. Stimulates leaf curling (epinasty) c. Stimulates fruit ripening Because of this activity, ethylene is known as ripening hormone. d. Promotes flowering in Mango, pineapple and some ornamentals. e. Hastens leaf abscission and falling down of leaves due to formation of abscission layer. f. Determines sex expression in monoecious plants, plants that produce both male and female flowers on the same plant. Application of ethylene causes more female flowers in cucurbits. 3. ### 5. Abscisic Acid (ABA): ### Physiological Role in Plants: a. **Closure of Stomata:** During drought, leaves synthesize large amounts of ABA which causes stomata to close. Thus, ABA acts as a messenger and enables plants to conserve water during drought b. **Delays seed dormancy:** Applying ABA delays seed germination. It controls bud dormancy, counteracts the effects of other hormones. It inhibits cell growth that is promoted by IAA. It inhibits amylase production that is induced by Gibberellins thus delaying seed germination. It induces chlorosis and senescence unlike cytokinins that promote rejuvenation of leaves and delay senescence. +-------------+-------------+-------------+-------------+-------------+ | | **Formulati | **Dose** | **Product | | | | on** | | Name** | | +=============+=============+=============+=============+=============+ | | SL | 45 g/l | Planofix | | +-------------+-------------+-------------+-------------+-------------+ | | DP | 1 g/kg | Seradix B | | | | | | No 1 | | +-------------+-------------+-------------+-------------+-------------+ | | DP | 3 g/kg | Seradix B | | | | | | No 2 | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 8 g/kg | Seradix B | | | | | | No 3 | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 32 g/l | ProGibb 4% | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 19/19 g/l | Promalin | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 480 g/l | Ethrel | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SC | 250 g/l | Cultar | | +-------------+-------------+-------------+-------------+-------------+ | | SP | 850 g/kg | B-Nine SP | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 360 g/l | Glyphosate | | | | | | 360 | | | | | | | | | | | | Acid | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 360 g/l | Mamba 360 | | | | | | SL | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 360 g/l | Roundup | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 360 g/l | Roundup | | | | | | Ultra | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 50 g/l | Pix | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 750 g/l | CeCeCe 750 | | +-------------+-------------+-------------+-------------+-------------+ | | SL | 300/150 | Uprite | | | | | | | | | | | g/l | | | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | SC | 120/60 | Dropp Ultra | | | | | | | | | | | g/l | | | +-------------+-------------+-------------+-------------+-------------+ 5. Other Pesticides =================== (Acaricides, Nematicides & Rodenticides) ---------------------------------------- Acaricides: ----------- a. First Generation Acaricides: Bridged diphenyls (bromopropylate, chloropropylate, chlorobenzilate, chlorfenethol, dicofol, tetradifon), the first specific acaricides, established themselves on the market in the 1950s. b. Second Generation Acaricides: During the 1960s and early 1970s, the second generation of specificacaricides emerged, the most important of which were propargite, organotins (cyhexatin, fenbutatin-oxide) and formamidines (amitraz, chlordimeform). c. Specific acaricides of third generation: represented by mite growth inhibitors. eg: Hexythiazox. Nematicides ----------- +-----------------------+-----------------------+-----------------------+ | | | **Mode of | | | | effectiveness** | +=======================+=======================+=======================+ | | | Nonsystemic | | | | insecticide/nematicid | | | | e | +-----------------------+-----------------------+-----------------------+ | | | Systemic in action | +-----------------------+-----------------------+-----------------------+ | | | Burrowing nematode, | | | | *Radopholus similis,* | | | | | | | | *Rotylenchulus | | | | reniformis* | +-----------------------+-----------------------+-----------------------+ | | | lesion nematode | | | | *Pratylenchus | | | | penetrans* on potato | | | | and | | | | | | | | root knot nematodes | | | | (*Meloidogyne* spp.) | | | | on tobacco and | | | | *Meloidogyne | | | | arenaria* on peanut | +-----------------------+-----------------------+-----------------------+ | | | *Meloidogyne sp., | | | | Rotylenchulusreniform | | | | is* | +-----------------------+-----------------------+-----------------------+ | | | Systemic nematicide | +-----------------------+-----------------------+-----------------------+ | | | *Pratylenchuspenetran | | | | s* | +-----------------------+-----------------------+-----------------------+ | | | *Contact& stomach | | | | pesticide aginst root | | | | knot nematode* | +-----------------------+-----------------------+-----------------------+ 5.3. Rodenticides: ------------------ Conclusion: ----------- #### Best Practices Recommended for Input Dealers: i. Always be sure that the right kind of pesticide as per the use classification is sold to the farmer. ii. Read the label for the recommended doses and toxicity classification and advice the farmer to use the protective equipment as per the recommendations. iii. Educate the farmer to follow the instructions on the manufacturer's label pertaining to pesticide usage. Practical on Classification of Pesticides (1 hour) ================================================== -- -- -- -- Importance of Packaging and labelling ===================================== Objectives of Packaging and labelling: -------------------------------------- 2. Packaging types --------------- 1. Packaging may be looked at as being of several different types. It is sometimes convenient to categorize packages by layer or function: \"primary\", \"secondary\", etc. Primary packaging is the material that first envelops the product and holds it. This usually is the smallest unit of distribution or use and is the package which is in direct contact with the contents. 2. Secondary packaging is outside the primary packaging, perhaps used to group primary packages together. 3. Tertiary packaging is used for bulk handling, warehouse storage and transport shipping. 3. Leaflet Information: -------------------- a. The plant disease, insects and noxious animals or weeds for which the insecticide is to be applied, the adequate direction concerning the manner in which the insecticide is to be used at the time of application; b. particulars regarding chemicals harmful to human beings, animals and wild life, warning and cautionary statements including the symptoms of poisoning suitable and adequate safety measures and emergency first-aid treatment where necessary; c. cautions regarding storage and application of insecticides with suitable warnings relating to inflammable, explosive or other substance harmful to the skin; d. instructions concerning the decontamination or safe disposal of used containers; e. a statement showing the antidote for the poison shall be included in the leaflet and the label; f. if the insecticide is irritating to the skin, nose, throat or eyes, a statement shall be included to that effect. g. Common name of the insecticide as adopted by the International Standards Organisation and where such a name has not yet been adopted such other name as may be approved by the Registration Committee. 4. Manner of labelling ------------------- i. Name of the manufacturer ii. Name of insecticide i. Registration number of the insecticide. ii. Kind and name of active and other ingredients and percentage of each iii. Net content of volume. iv. Batch number. v. Expiry date, i.e. up to the date the insecticide shall retain its efficiency and safety. vi. Antidote statement. Session II: =========== Pesticide Formulations ====================== 1. **Types of Pesticide Formulations** 1.1 Introduction: ----------------- 2. Characteristics of Technical Grade Pesticides: ---------------------------------------------- a. High purity hence, very low quantity of chemical need to be sprayed over large surface area which is very difficult and cannot be uniform. b. Solids or liquids or thick viscous pasty materials because of which spraying or broadcasting them is very difficult over the large area. c. Low water solubility: This makes their application in the field very difficult. d. Toxic to mammals in varying degree: Technical grade chemicals are extremely to highly toxic which will be fatal to the operator, farm labor besides causing environmental hazard. e. Low selectivity: All the pesticides do not have inherent property to adhere and translocate in the plant system. f. Low storage Stability: Some of the compounds do not possess storage stability unless stabilizers are added. Advantages of Pesticide Formulations over technical grade Pesticides: --------------------------------------------------------------------- ### Easy handling and application: ### To facilitate dilution at field level: ### To reduce Toxic Hazards: ### To improve efficacy of the pesticide: ### To achieve selectivity: ### Economics: i. purpose of pesticide use ii. manner in which the control is to be affected iii. mode of application iv. physico-chemical properties of the a.i. v. weather conditions of application vi. economic considerations vii. ready availability of formulation auxiliaries a. *Concentrated formulations*: They must be mixed with water, or some other carrier, before being applied. They are very economical when treating large areas but it may be hard to measure amounts needed for small areas. Also, the handling, mixing, need for specialized spray equipment, and clean-up time may make the use of concentrates inconvenient. *Example*: emulsifiable concentrate, suspension concentrate etc. b. *Ready-to-Use formulations*: They may be more appropriate for small areas. They contain small amounts of active ingredient (often 1% or less a.i. per unit volume). Some contain petroleum-based solvents; others are water-based. RTU formulations are already diluted and may be sold in containers that serve as applicators. Example: granules, aerosol, baits etc. 4. Types of Pesticide Formulations: -------------------------------- 1. ### Solid formulations: a. **Dustable powder or Dust (DP)**: Dusts are manufactured by the sorption of an active ingredient onto a finely-ground, solid inert such as talc, clay, or chalk. They are relatively easy to use because no mixing is required and the application equipment. Dusts can provide excellent coverage, but the small particle size that allows for this advantage also creates an inhalation and drift hazard. In general, dust formulations are no longer used in large scale outdoor situations due to their high drift b. **Granule (GR) and Pellet (PT)**: The manufacture of granular formulations is similar to that of dusts except that the active ingredient is sorbed onto larger and heavier particles. The inert solid may be clay, sand, or ground plant materials. A granule is defined by size: granule-sized products will pass through a 4-mesh (number of wires per inch) sieve and be retained on an 80-mesh sieve. Granules are applied dry and usually are intended for soil applications where they have the advantage of weight to carry them through foliage to the ground below. The primary drawbacks of granules are their bulk, the problems they present in handling, and c. **Wettable powder (WP)**: Pesticide in dry form with surfactant, often mixed or coated on a fine solid carrier for dispersion in water to form a suspension which is called as wettable powder formulation. Wettable powders are finely divided solids, typically mineral clays, to which an active ingredient is sorbed. The particles do not dissolve in water. They settle out quickly unless constantly agitated to keep them suspended. WPs contain 5-95% active ingredient by weight (usually 50% or more). This formulation is diluted with water and applied as a liquid spray. Upon dilution, a suspension is formed in the spray tank. Wettable powders contain wetting and dispersing agents as part of the formulation. They provide an ideal way to apply an active ingredient in spray form that is not readily soluble in water. Wettable powders tend to pose a lower dermal hazard in comparison to liquid formulations, and they do not burn vegetation as readily as many oil-based formulations. This formulation does present an inhalation hazard to the applicator during mixing and loading because of the powdery nature of the particles. d. **Water dispersible granule (WG or WDG)**: Dry flowables or water dispersible granules, as they are sometimes called are manufactured in the same way as wettable powders except that the powder is aggregated into granular particles. They are diluted with water and applied in a spray exactly as if they were a wettable powder. Dry flowables, as would be expected, form a suspension in the spray tank; they have basically the same advantages and disadvantages as wettable powders, with several important exceptions. During the mixing and loading process, dry flowables pour more easily from the container ### Liquid formulations: a. **Emulsifiable concentrate (EC)**: EC is a clear liquid homogeneous formulation of active ingredient(s) which form emulsion after dilution with water. It is a solution of a.i. and surfactant in water immiscible solvent(s), which on addition b. **Suspension concentrate (SC)**: Liquid flowable or suspension concentrate is the designation for a stable suspension of active ingredient(s) in an aqueous continuous phase, intended for dilution with water before use. A SC formulation contains finely divided solid particles in a liquid dispersing medium, usually water. The proportion of the solid usually ranges from 5 to 60% which may be a single a.i. or a mixture of several active ingredients with or without a carrier. They are becoming much more important because of increasing solvent costs and environmental restrictions on pesticide auxiliary materials. This formulation disperses spontaneously when poured in water having good suspension stability. c. **Emulsion concentrate (EW)**: It is a stable emulsion of active ingredient(s) in an aqueous phase, intended for dilution with water before use. The active ingredient is normally a liquid and forms the dispersed oil phase, but it is also possible to emulsify a solid or liquid active ingredient dissolved in a water immiscible solvent. The solvents, whenever used, are added in very small amount. Thus, the emulsion concentrates are more economic in view of the ever rising solvent costs, reduced operator hazard and phyto-toxicity. In EW, pesticidal *a.i.* in organic liquid is dispersed as fine globules in continuous water phase. The globules may take the size ranging from macro (500-1000 µ) to micro (3-10 µ). d. **Soluble Liquid (SL)**: It is a clear to opalescent liquid which is to be applied as a solution of the active ingredient(s) after diluting in water. It comprises the solution of the *a.i.* in suitable solvent(s), along with other necessary formulants. The SL formulation is free from any visible suspended matter and sediment, to be applied as a true solution of *a.i.* in water. The number of pesticides that can be formulated in this simple way is limited due to solubility and/or hydrolytic stability. Some acid herbicides and plant growth promoter hormones are being formulated in SL formulation. e. **Micro-emulsion (ME)**: A micro-emulsion is a mixture of water, water insoluble and water soluble components forming a visually homogeneous, transparent liquid. One or more active ingredients may be present in either the aqueous phase, the non-aqueous phase, or in both phases. Micro-emulsions will disperse into water to form either conventional emulsions or dilute micro-emulsions. f. **Suspo-emulsion (SE)**: An aqueous suspo-emulsion is a mixture of water-insoluble active ingredients dispersed in an aqueous solution, where one g. **Aerosol (AE)**: An aerosol is a suspension of solid or liquid particles with a diameter less than 50 µ, in air or gas. This is a self-contained sprayable **Preferred diluent** -- -- ----------------------------- Aromax, xylene, solvent CIX Isopropyl alcohol, China clay Bentonite, coarse sand Soap stone, talc Formulations for Seed Treatment: -------------------------------- 2. Types of Sprayers and Dusters ================================ -- -- -- -- ***Powered operated*** -- ---------------------------------- 1\. Knap sack, motorized type 2\. Hand/ Stretcher carried type 1. Hand held battery operated ULV sprayer. 2. Knapsack motorized type 3. Tractor/ vehicle mounted ULV sprayer 4. Aircraft ULV sprayer 1. Aerosol sprayers 2. Liquefied-gas type dispensers 3. Fogging machines 4. Exhaust Nozzle Sprayer -- -- -- -- -- -- -- -- ### HIGH VOLUME SPRAYING APPLICATORS ### Slide pump or hand sprayers ### Stirrup pump sprayer ### Compression sprayer ### Foot operated sprayer ### Rocker sprayer ### Lever operated knapsack sprayer ### High pressure power sprayer ### LOW VOLUME SPRAYING APPLICATORS V. spraying technique is reduced to 50 to 150 L/ha in L.V. spraying technique. 1. Air velocity and volume 2. Liquid flow rate 3. Properties of spray liquid ### ULTRA-LOW VOLUME SPRAYING APPLICATORS ### DUSTERS AND DUST APPLICATORS 1. Ready to use product reduces field tasks concentrate handling and further dilution (as in case of spraying) 2. In dryland agriculture where water is scare. ### 2.4.1 Manually operated dusters #### Plunger duster: #### Bellows type duster: #### Hand rotary duster: #### Power duster #### Knapsack duster ### Precautions ### Maintenance Spray Nozzles and Their Classification ====================================== ### HYDRAULIC ENERGY NOZZLES 1. Hollow cone type 2. Fan type 3. Impact type ### Hollow cone nozzles: ### Fan nozzle: ### Impact nozzle: ### Adjustable nozzle: 2. **GASEOUS ENERGY NOZZLES** CENTRIFUGAL ENERGY NOZZLES -------------------------- ### THERMAL ENERGY NOZZLES 5. **Different target and optimum droplet size** -- -- -- -- Session III: ============ Calibration and Care of Pesticide Application Equipment ======================================================= Methods of calibration: ----------------------- \- -- ---- -- \- 1. Nozzle spray discharge rate 2. Swath width 3. Walking speed of operator 2. Care and maintenance of plant protection equipment -------------------------------------------------- 1. ### General maintenance: 1. Clean outer surface with brush or cotton waste by using kerosene oil or plenty of water. 2. Oil the moving or rubbing surfaces of parts with lubricating oil (SAE 30) or grease, if needed. 3. Filter or strain the chemical solution/ fuel oil mixture while pouring into the tanks. Make the caps or lids leak-proof with gaskets. 4. Flush the equipment with clean water to wash inside parts of containers, tubes and nozzles to be free from chemicals. 2. ### Care and upkeep of hand sprayer & duster: 5. Dry and sieved dust should be used for dusters. 6. Grease the duster gear box once in a month. 7. Clean the duster after the work by removing all dust from the hopper. 8. Oil the cup washers and bucket washers of sprayer frequently. 9. Spray tank discharge lines and nozzles should be flushed with clean water after the day\'s work. 10. Lances and nozzles should not keep on the ground. Nozzle parts should be cleaned with a brush. 3. ### Care and upkeep of power sprayers and dusters: 1. Lubricating oil level should be checked and maintained in four stroke engines daily. 2. Mixture of engine oil and petrol in correct proportions should be used for two stroke engines, duly stirred and strained. 3. Clean the Air and Fuel filters with petrol frequently. 4. All the nuts and bolts should be tightened once in a week. 5. Check up the pressure gauges and safety valves frequently. 6. Drain the fuel tank after the day\'s work. 7. Stop two stroke engines by closing the petrol cock. 8. Belts should be kept tightened always, to be free from slip and slackness. 9. Keep proper inflated pressure in the tyred wheels of power sprayers. 10. Rubber tyre equipment should be rested on steel props when stationed. 11. Rubber hoses should not be bent at angles and dragged on the ground. 12. Equipment should be stored in clean, dry, cool store room. 4. ### Care and upkeep of pp equipment when not in use: 1. Plant Protection Equipment should be arranged properly in a store house. They should be protected from sunlight. 2. Equipment of one category should be kept at one place and not in a mixed up fashion i.e., do not dump the equipment. 3. Attachment like discharge lines, lances, and nozzles should not be kept attached to the equipment. 4. The equipment should be cleaned with cotton waste every day and polished once in a month. 5. The rubber/ plastic delivery hose should be coiled forming a big circle instead of small spool. Otherwise the hose pipes break or crack when they are straightened. 6. All nozzles should be kept neat and clean separately. 7. The moving parts and washers are to be oiled or greased well once in a week. 8. The equipment should be tested for its normal performance once a week. Even the engines should be run for a short while. 9. The equipment in store should be classified and labelled to indicate its conditions as: i. Working condition ii. Needs servicing & repairs iii. Needs parts & repairs iv. Not serviceable 10. Rubber tires should be inflated regularly or they should be jacked and propped. ### 4.2.5 Care and upkeep of pp equipment when taken to field: 1. Always carry tools required for attending to field troubles. 2. Carry some spares like washers, filters, gaskets & pins to the field. 3. Carry small quantity of kerosene, petrol, engine oil, grease, cotton waste, and containers. 4. Carry the Plant Protection Equipment properly and carefully. 5. Do not drop the equipment or attachments on the ground. 6. Clean the equipment before and after work is over. 7. Flush the equipment with clean water, after work is over. 8. Oil the moving parts and apply grease on gears and in grease cups. 9. Filter the chemical liquids and fuel oil mixtures before filling.