Surfactants are classified by how they split apart into charged atoms or molecules, called ions.
Anionic surfactants have a negative (-) charge. They are most often used with contact pesticides, which control the pest by direct contact instead of being absorbed into it systemically.
Cationic surfactants have a positive (+) charge. Do not use them as stand-alone surfactants often, they are phytotoxic.
Nonionic surfactants have no electrical charge. They are often used with systemic products to help pesticides to penetrate plant cuticles. They are compatible with most pesticide products. A pesticide can behave very differently in the presence of an anionic, cationic, or nonionic surfactant. For this reason, you must follow label directions when choosing one of these additives. Selecting the wrong surfactant can reduce efficacy and damage treated plants or surfaces.
The terms used with pesticide additives can be confusing. People sometimes use the words adjuvant and surfactant interchangeably. However, an adjuvant is ANY substance added to modify properties of a pesticide formulation or finished spray. A surfactant is a specific kind of adjuvant one that affects the interaction of a spray droplet and a treated surface. All surfactants are adjuvants but not all adjuvants are surfactants. For example, drift control additives and safeners are not surfactants.
-Read and follow the label. Is an adjuvant recommended? If so, what type? Do not make substitutions. Some product labels may recommend an adjuvant for one type of use or site but prohibit any kind of adjuvant for another labeled use or site. Suppose, for example, that a certain product is formulated with a wetting agent. If you add another wetting agent when you mix and load a foliar-applied spray, the product may not give better spreading and coverage. Instead, the extra adjuvant may increase runoff, reduce deposition, decrease efficacy and even damage the target plant.
-Use only those adjuvants manufactured for agricultural or horticultural uses. Do not use industrial products or household detergents in pesticide spray mixes.
-No adjuvant is a substitute for good application practices.
-Be skeptical of adjuvant claims such as â€œimproves root uptakeâ€ or â€œkeeps spray equipment cleanâ€ unless a reliable source can provide research-based evidence to support them. Only use adjuvant products that have been tested and found effective for your intended use.
-Test spray mixes with adjuvants on a small area before proceeding with full-scale use.
Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant. For example, scientists can take the gene for the Bt pesticidal protein and introduce the gene into the plant’s own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest. The protein and its genetic material, but not the plant itself, are regulated by EPA.
Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest[s]. For example, there are fungi that control certain weeds and other fungi that kill specific insects.
The most widely used microbial pesticides are subspecies and strains of Bacillus thuringiensis, or Bt. Each strain of this bacterium produces a different mix of proteins and specifically kills one or a few related species of insect larvae. While some Bt ingredients control moth larvae found on plants, other Bt ingredients are specific for larvae of flies and mosquitoes. The target insect species are determined by whether the particular Bt produces a protein that can bind to a larval gut receptor, thereby causing the insect larvae to starve.
Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest. Biochemical pesticides include substances that interfere with mating, such as insect sex pheromones, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide, EPA has established a special committee to make such decisions.
Sophorolipids (SLPs) are the most promising glycolipid biosurfactants produced in large quantity by several nonpathogenic yeast species, among these Candida bombicola ATCC 22214 is the most studied SLP producing yeast.
SLPs composed by the disaccharide sophorose (2’-O-β-D-glucopyranosyl-β-D-glycopyranose) linked (β – glycosidically) to a long fatty acid chain with generally 16 to 18 atoms of carbon with one or more unsaturation.
These compounds have characteristics, which are similar or even superior to the other biosurfactants and surfactants.
Some of these advantages are environmental compatibility, high biodegradability, low toxicity, high selectivity and specific activity in a broad range of temperature, pH and salinity conditions.
They fulfill the eco-friendly criteria combine Green chemistry and a lower carbon footprint. SLP possess a great potential for application in areas such as: Agriculture, Food, Biomedicine, Bioremediation, Cosmetics and Enhanced Oil Recovery.
Tripterygium wilfordii has many effects, such as clearing heat and detoxicating, expelling wind and clearing collaterals, relaxing tendons and activating blood circulation, and has certain curative effects on rheumatoid arthritis, nephritis, lupus erythematosus and other diseases.
The main active components of Tripterygium wilfordii are triptolide, tripterygium glycoside, triptolide, etc.
It is reported that Tripterygium wilfordii preparation has certain reproductive toxicity, and the damage to the reproductive system of male rats is mainly manifested by the increase in the number of sperm with abnormal morphology, and the decrease of sperm motility and vitality; High-dose or long-term use of drugs will also cause testicular spermatogenic cells to fall off, reduce or even disappear, thus affecting the occurrence of sperm; Decreases the activities of testicular acid phosphatase (ACP), hyaluronidase (HASe), succinate dehydrogenase (SDH) and phosphofructose kinase 1 (PFK1) and other related enzymes; Inhibit the key enzymes required for the synthesis of inhibin B (INHB) and testosterone, thus producing reproductive toxicity to male rats.
Tripterygium wilfordii is one of the most poison traditional Chinese herbal medicines in China.
The toxicity of Tripterygium wilfordii is very high. It has long been used to prevent and control various insects, rodents and mites.