Herbicide Formulation A herbicide preparation supplied by the

Herbicide Formulation: A herbicide preparation supplied by the company for practical use. n n A mixture of the herbicide (Active ingredient), solvent(s), diluent(s) and surfactant(s). The herbicide is the active ingredient in the formulation. n The formulations are packaged and sold as trade-named products. n A given chemical may be formulated in a variety of differing formulations and sold under different trade names.

Purpose of formulation n To enable farmers to disperse the herbicide in a convenient carrier such as water and to allow to spray in this convenient carrier. n To enhance the phytotoxicity of the herbicide. n To handle, store and spray properly-Easy to handle n To improve the longevity of the herbicide-Improve shelf life n To protect the herbicide from bad weather of environment during storage n Practical value-Pure forms of herbicides are practically useless to us and rarely available as pure chemicals

Types/Formulations Herbicide are purchased liquid or dry: n Liquid application: n n Purchased as liquid or dry Water soluble n n n Oil or solvent soluble n n n Liquid SP (Soluble powder) EC (Emulsifiable concentrate) ME Neither water or oil soluble n n WP (Wettable powder) FL (Flowable liquid)

Types/Formulations n Dry application n Granules (G) and Pellets (SP)-Applied without a liquid or a carrier-applied directly to the soil surface. Rain/irrigation breaks down the granules or pellets and water soluble herbicide is leached into the soil. Same herbicide may be formulated in two or more types of formulations. For example, 2, 4 -D is formulated as water-soluble, oil soluble and emulsifiable-concentrate. n

2, 4 -D n n 2, 4 -D: (2, 4 dichlorophenoxyacetic acid) is one of the most common systemic herbicide used in to control broadleaf weeds in grasses. Third most widely used herbicide in North America and the most widely used herbicide in the world

Types/Formulations n Applied as wet sprays or as dry material. Wet spray formulations vary according to: n The solubility of the active ingredient in water, oil, and organic solvents: n Water-soluble (S or WS)-form true solution when mixed with water-water is the solvent and the carrier. Emulsifiable-concentrates (E or EC)-water is the carrier-form an emulsion when mixed with water rather than a true solution (Select®, GOAL) Emulsifier is a substance that promotes the suspension of one liquid in another (Oil in water). Renovate, WS herbicide n Glass. Clear EC herbicide

Types/Formulations n n Wettable powders (WP)-Dry formulation that can be suspended in water; water is carrier-low solubility in water-unstable suspension-needs continuous agitation (Bladex 80) Oil-soluble (OS)-Diesel oil is the carrier (Banvel-520) n Liquid (L)-water is the carrier (Repco Kill III). Careful application of liquid herbicides may be needed to treat small areas of dense, broadleaf weed growth. n Ultra-low-weight granules (ULW)-No carrier, -the liquid formulation may be applied directly. (Velpar) n Water-soluble-Granules (SG)-similar to WP, easy to handle. (Total Sol tm) n Dry material- Dry formulations are mostly formulated as granules and pellets (Roundup pro, Devrinol 50 -DF)

VELPAR ® DF water dispersible granule to be mixed in water Roundup broadspectrum herbicide

Surfactants, adjuvants or surfaceactive agents n n They are materials added to spray solutions to improve the performance of foliar-applied herbicides. They are widely used in herbicide formulations to improve the emulsification, dispersion, spread, sticking and penetration of the herbicide molecules into plants. n Reduces surface tension of water droplet and better contact with leaf surface. n Examples of surfactants are Triton xseries, Tween series, X-77. Triton X-series, liquid appearance

Surfactants n n Different formulations and surfactants will be on display in the laboratory. Observe the color of the solution when the herbicides are mixed with water.

Surfactant classes and their general usage. n n non-ionic surfactants (NIS); all purpose (ie. , X -77) These surfactants are good dispersing agents, stable in cold water, and have low toxicity to both plants and animals BINDE EXTENDER NONIONIC STICKER SPREADER

Surfactant classes and their general usage. - crop oil concentrates (COC) - used primarily with grass herbicide (Agri- Dex) n crop oils keep the leaf surface moist longer than water, allowing more time for the herbicide to penetrate > increasing the amount of herbicide that will enter the plant. n composed of a blend of paraffinic-based petroleum VIGOR oil and surfactants. A premium-grade crop oil concentrate

Surfactant classes and their general usage. - nitrogen-surfactant blends - used primarily with broadleaf herbicides (ie. , AMS) n n n consist of premix combinations of various forms of nitrogen and surfactants. Generally are used with herbicides recommending the addition of ammonium sulfate or 28 percent nitrogen. Reduce surface tension and improve leaf surface spreading. n DELIVER Ams + Nonionic Surfactant

Surfactant classes and their general usage. - Esterified seed oils; all purpose (Sun-it II) - Produced by reacting fatty acids from seed oils (corn, soybean, sunflower, canola) with an alcohol to form esters.

Surfactant classes and their general usage. - - - organo-silicone; all purpose (Herbex) usually silicone/surfactant blends of silicone Provide tremendous reduction in surface tension and spread more than conventional surfactants. SURCIL

Think of the followings questions that could be included in the final exam n Different formulations and surfactants will be on display in the laboratory. n Observe the color of the solution when the herbicides are mixed with water. n n n What is emulsifiable herbicide? What is a wettable powder formulation? What is meant by a designation such as W-50 or WP 50%? What is X-77? What are the significant implications of herbicide formulations

Mixing and Spraying BEFORE CALIBRATION. CHECK SPRAYER PARTS (NOZZLE TIPS, SCREENS ETC. ) CALIBRATION: Calibration is the output per unit area (e. g. , l or kg/ha). It depends on: n Speed of application n Equipment output/unit time n Width of application AFTER CALIBRATION n Read the product label n Wear protective clothing- Protective clothing and devices should be worn to protect the operator from excessive exposure. n Half fill the sprayer tank with water n Shake the product n Add and mix the product with water in a small bucket then pour the solution into the tank. n Finally top up the tank with water to the required level.

Calculations & Applications: n n After you have calibrated your sprayer, the second step is to calculate how much chemical should be added to the sprayer. Recommended rates are usually given as a rate of the active ingredient per unit area or per volume (e. g. 2. 0 kg a. i. /ha; X kg a. i. /gal or X g a. i/L). Such information is found on the label of the container and is expressed in grams/liter or as a percentage. Therefore, it is necessary to calculate how much of purchased material contains the required active ingredient

The following formula is used to calculate the amount of the herbicide to be applied to a given area: n n Liquid Formulations. Amount of commercial product (Litre) required/ha = (Kilograms or grams) of active ingredient/ha recommended____ (Kilograms or grams) of active ingredient/litre in the formulation n (Written on the label) Wettable Powder Formulations. Kilograms or grams of formulated herbicide to use/ha = Kilograms or grams of active ingredient/ha recommended__ % a. i. in formulation (written on the label)

With respect to the use of herbicides, one must exercise great care in their transport, storage, mixing and disposal Herbicides should be stored in their original containers in a separate building that is clearly marked and secured

Turf Damage due to misapplication of herbicides A sprayer contaminated with residues of a nonselective herbicide was used to apply a pesticide to this turf. The lesson learned from this experience was that sprayers should be thoroughly cleaned after each use

Misuse includes n n n Applying improper rate Applying wrong herbicide Improper calibration Improper method of application Improper timing of herbicide application Improper soil incorporation

Calibration problems n A farmer has a boom sprayer 10 m long with nozzles spaced 50 cm apart. He wants to calibrate his sprayer at 600 l/ha, and apply Atrazine (50 %) at 1 kg a. i/ha over an area of 25 du. How many kgs of commercial Atrazine he needs? n Calculate the amount of water needed to for 25 du. n