Practical Applications of Herbicide Physiology Glossary

absorption

The process of moving a substance from the exterior of a plant to the internal portion.

bolting

Flower stalk elongation.

contact

Process resulting in two objects (i.e. herbicide molecule and a plant) touching each other.

cuticle

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

diffusion

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

mass flow

Process by which a dissolved or suspended molecule is moved with movement of the solvent, i.e., a floating piece of wood moving with the current in a stream.

meristems

Area of cell division.

metabolism

Process resulting in a change in chemical structure of a herbicide.

oil additives

An additive made either synthetically or extracted from seeds that enhances herbicide uptake.

resistance

The inherited ability of a population to survive and reproduce following repeated exposure to a dose of herbicide normally lethal to the wild type. Resistance may also be induced by such techniques as genetic engineering or selection of variants produced by tissue culture or mutagenesis.

selectivity

Differential affect on a mixed population.

shoots

Portion of the developing seedling above the root system.

site of action

Point in biochemical pathway at which a herbicide functions.

site of uptake

Plant part through which a herbicide is absorbed.

surfactants

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

susceptible

Sensitive to a stimulus.

tolerant

The survival of a normal weed species population following treatment with a herbicide at a rate lethal to other species.

translocation

Movement from one point to another within a plant.