SPECIFICITY
- A selective herbicide does not harm certain crops and destroys a number of weeds from those crops.
- A total herbicide may destroy or hinder the development of all vegetation and remains active for a long period.
MODE OF ACTION
- A root-penetration (absorption) herbicide is applied to the soil, it penetrates by the underground organs of the plant (roots, seeds, plantlets)
- A leaf-penetration herbicide is applied on the foliage, it penetrates through the aerial organs of the plant (leaves, petioles, stems)
- A contact herbicide acts after penetrating into the tissues, without any migation from one organ of the treated plant to another
- A systemic herbicide is able to act, after penetration, by migrating from one organ of the treated plant to another.
SPRAY PERIOD
- Pre-sowing treatment : after the soil penetration and before the sowing of the crop; this enables in particular the incorporation of volatile or photo-degradable products
- Post-sowing treatment : immediately after the sowing
- Pre-emergence treatment : before the emergence of the concerned plant (crop or weed)
- Post-emergence treatment : after the emergence of the concerned plant (crop or weed)
- Early post-emergence treatment: before the crop germinates, but after that of the weeds ; treatment associating a pre-emergence herbicide and a post-emergence herbicide.
TYPE OF SPRAY
- complete cover treatment : on all the surface of the plot
- localised treatment: on part of the soil, of the crop or of the weeds
- directed treatment : treatment done with a non-selective herbicide ; while protecting the cultivated plant during application.
Some definitions of terms associated to herbicides
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Sources :
A.C.T.A., 2000. Index phytosanitaire. 36e édition. Association de coordination technique agricole. Paris. 644 p.
Deuse J. & Lavabre E.M., 1979. Le désherbage des cultures sous les tropiques. Maisonneuve et Larose. France. 310 p.
- Association : preparation containing several active ingredients
- Proportion : quantity of active ingredient or of applied preparation per unit of treated (to avoid any ambiguity, the proportions of active ingredients are expressed in grams and those of applied special preparations in kilos or litres).
- Formulant : any substance added to the active ingredient(s) to obtain the formulated product
- Formulation : combination of various components aiming at making the prodct efficiently usable for the wanted result. Physical form under which the phytopharmaceutical product is put on the market (CS : suspension of capsules; EC : concentrat emulsifiable; SC : concentrated suspension; SE : suspension - emulsion; SL : concentrated soluble; SP : soluble powder in water; WG : granules to be spread I water; WP : powder to wet; etc...).
- Graminicide : substance or herbicide preparation having a specific action on grasses and a selective one on dicotyledons.
- Phytotoxicity : propriety of a substance or a preparation that provokes momentary or lasting alterations in a plant.
- Active ingredient : component of a preparation to which part of or all its efficiency is atributed
- Preparation ou formulated product: mixture ready to use of an active matter and of formulants (cf : association)
- Residual activity : time during which a herbicide product displays its activity.
- Speciality : formulated product of defined composition, authorized for sale under a registered name
- Efficiency spectrum: the whole of the species controlled by a product at a given dosage
- Contents : quantity of active ingredients contained in a mass or unit volume of a preparation ; it is expressd in weight percentages for solid formulations and in g/l for liquid formulations.
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