<unk> s are often classified according to their site of action, because as a general rule,<unk> s within the same site of action class will produce similar symptoms on susceptible plants. Classification based on site of action of the<unk>  is preferable as<unk>  resistance management can be handled more effectively. Classification by mechanism of action (MOA) indicates the first enzyme, protein, or biochemical step affected in the plant following application. List of mechanisms found in modern<unk> s * ACCase inhibitors: Acetyl coenzyme A carboxylase (ACCase) is part of the first step of lipid synthesis. Thus, ACCase inhibitors affect cell membrane production in the meristems of the grass plant. The ACCases of grasses are sensitive to these<unk> s, whereas the ACCases of dicot plants are not. * ALS inhibitors: Acetolactate synthase (ALS; also known as acetohydroxyacid synthase, or AHAS) is part of the first step in the synthesis of the branched-chain amino acids (valine, leucine, and isoleucine). These<unk> s slowly starve affected plants of these amino acids, which eventually leads to inhibition of DNA synthesis. They affect grasses and dicots alike. The ALS inhibitor family includes various sulfonylureas (SUs) (such as flazasulfuron and metsulfuron-methyl), imidazolinones (IMIs), triazolopyrimidines (TPs), pyrimidinyl oxybenzoates (POBs), and sulfonylamino carbonyl triazolinones (SCTs). The ALS biological pathway exists only in plants and not animals, thus making the ALS-inhibitors among the safest<unk> s. * EPSPS inhibitors: Enolpyruvylshikimate 3-phosphate synthase enzyme (EPSPS) is used in the synthesis of the amino acids tryptophan, phenylalanine and tyrosine. They affect grasses and dicots alike. Glyphosate (Roundup) is a systemic EPSPS inhibitor inactivated by soil contact. * Auxin-like<unk> s: The discovery of synthetic auxins inaugurated the era of organic<unk> s. They were discovered in the 1940s after a long study of the plant growth regulator auxin. Synthetic auxins mimic this plant hormone in some way. They have several points of action on the cell membrane, and are effective in the control of dicot plants. 2,4-D, 2,4,5-T, and Aminopyralid are examples of synthetic auxin<unk> s. * Photosystem II inhibitors reduce electron flow from water to NADP+ at the photochemical step in photosynthesis. They bind to the Qb site on the D1 protein, and prevent quinone from binding to this site. Therefore, this group of compounds causes electrons to accumulate on chlorophyll molecules. As a consequence, oxidation reactions in excess of those normally tolerated by the cell occur, and the plant dies. The triazine<unk> s (including atrazine) and urea derivatives (diuron) are photosystem II inhibitors. * Photosystem I inhibitors steal electrons from ferredoxins, specifically the normal pathway through FeS to Fdx to NADP+, leading to direct discharge of electrons on oxygen. As a result, reactive oxygen species are produced and oxidation reactions in excess of those normally tolerated by the cell occur, leading to plant death. Bipyridinium<unk> s (such as diquat and paraquat) inhibit the FeS to Fdx step of that chain, while diphenyl ether<unk> s (such as nitrofen, nitrofluorfen, and acifluorfen) inhibit the Fdx to NADP+ step. * HPPD inhibitors inhibit 4-hydroxyphenylpyruvate dioxygenase, which are involved in tyrosine breakdown. Tyrosine breakdown products are used by plants to make carotenoids, which protect chlorophyll in plants from being destroyed by sunlight. If this happens, the plants turn white due to complete loss of chlorophyll, and the plants die. Mesotrione and sulcotrione are<unk> s in this class; a drug, nitisinone, was discovered in the course of developing this class of<unk> s.<unk>  group (labeling) One of the most important methods for preventing, delaying, or managing resistance is to reduce the reliance on a single<unk>  mode of action. To do this, farmers must know the mode of action for the<unk> s they intend to use, but the relatively complex nature of plant biochemistry makes this difficult to determine. Attempts were made to simplify the understanding of<unk>  mode of action by developing a classification system that grouped<unk> s by mode of action. Eventually the<unk>  Resistance Action Committee (HRAC) and the Weed Science Society of America (WSSA) developed a classification system. The WSSA and HRAC systems differ in the group designation. Groups in the WSSA and the HRAC systems are designated by numbers and letters, respectively. The goal for adding the “Group” classification and mode of action to the<unk>  product label is to provide a simple and practical approach to deliver the information to users. This information will make it easier to develop educational material that is consistent and effective. It should increase user's awareness of<unk>  mode of action and provide more accurate recommendations for resistance management. Another goal is to make it easier for users to keep records on which<unk>  mode of actions are being used on a particular field from year to year. Chemical family Detailed investigations on the chemical structure of active ingredients of the registered<unk> s showed that some moieties (moiety is a part of a molecule that may include either whole functional groups or parts of functional groups as substructures; a functional group has similar chemical properties whenever it occurs in different compounds) have the same mechanisms of action. According to Forouzesh et al. 2015, these moieties have been assigned to the names of chemical families and active ingredients are then classified within the chemical families accordingly. Knowing about<unk>  chemical family grouping could serve as a short-term strategy for managing resistance to site of action.
Herbicide
Amebicide
Fungicide
Prebiotic 
Deodorant
Herbal medicine
Insecticide
Pesticide