Foliar Absorption and Phloem Translocation Glossary


Process of moving a substance from one matrix into another.


A chemical compound that can donate a proton


Having a pH lower than 7, having a higher concentration of H+ ions.


An additive.  Any of several categories of compounds that can be added to a herbicide solution to enhance its activity; some examples are oils, surfactants and fertilizers.


One of the mineral forms of nitrogen in the gas form NH3.

cell wall

A thin, mechanically strong structure surrounding all plant cells consisting of a complex mixture of polysaccharides and other polymers that are secreted by the cell and are assembled into an organized network linked together by a mixture of covalent and noncovalent bonds. Cell walls regulate cell volume and determine cell shape.


Getting a herbicide to touch the surface of a plant either foliage or roots.


A plant's outer waxlike layer, composed of lipoidal waxes and hydrophilic cutin that acts as a protective layer over the epidermal cell wall.


A compartment in a plant or animal cell surrounding the nucleus in which many cell organelles and molecules are suspended.


Process whereby molecules move from areas of higher concentration to areas of lower concentration.


A herbicide which inhibits the production of amino acids.


A pesticide used to kill plants.


Having chemical properties relating to water (water-like).  Compounds are polar or ionizable and can be soluble in water; lipophobic.


Molecules with a positive or negative charge.

lipid bilayer

Made up of compounds which have both hydrophobic and hydrophilic moieties, this is the structure of membranes such as the cellular membrane.


Having chemical properties relating to lipids (lipid-like), nonpolar compounds that are highly soluble in organic solvents, but not water; hydrophobic.

log Kow

Octanol/water partition coefficient, relative measurement of how water soluble a chemical is. A compound with a low log Kow would be more water-soluble than a compound with a high log Kow.


Any substance or mixture of substances used for controlling, preventing, destroying, repelling, or mitigating any pest. A pesticide also includes any substance or mixture of substances intended for use as a plant regulator, defoliant, or dessicant.


Negative log of the hydrogen ion concentration (pH = -log [H+]), the higher the pH of an environment the less H+ ion concentration, the more basic the environment becomes.

plasma membrane

The semi-permeable membrane that surrounds the protoplasm of a cell.

relative humidity

The ratio of the amount of water vapor actually present in the air to the greatest amount possible at the same temperature.


The ability of a solute to dissolve in a solvent; the ability of a herbicide to dissolve in water.


A state change when a solid material is put into a solvent. The molecules leave the solid phase and go into the liquid phase of the solvent


An additive that reduces the surface tension of a herbicide to allow for better contact between water droplet and plant surface; cationic surfactants, ionic surfactants, nonionic surfactants; SURFace ACTive AgeNT.


An additive that reduces the surface tension of a droplet allowing for better contact between water droplet and plant surface.


An additive that reduces the surface tension of a droplet allowing for better contact between water droplet and plant surface.


Moving from one point to another within a plant by either the xylem or phloem.