CAPILLARY PORE SPACE. The sum of smaller pore spaces which hold water by capillary tension against the pull of gravity.

CARRIER. An inert solid or liquid material (clay, dust, air, water) mixed with a pesticide or fertiliser, and serving as a vehicle for the active ingredient to improve its dispersion.

CARYOPSIS. The grain or fruit of grasses.

CATION EXCHANGE CAPACITY. The ability of soil colloids to hold ions to their surfaces by surface charges. Expressed as meg/100g soil.

CAUSAL AGENT. The organism that produces a given disease.

CAUTION. A signal word indicating a category III pesticide. A low toxicity pesticide with an oral LD of 500-5000 mg/kg of body weight, and a dermal of 2,000 to 20,000.

CERTIFIED SEED. Grass seed that is produced under the inspection of a certifying agency. The agency must approve the quality of the seed before it is sold.

CHELATE. A chemical which by its structure forms a molecular cage around an ion, the cage shielding the ion from its normal reactions.

CHLOROSIS. A yellow, to white, to grey condition of a normally green plant tissue resulting from the partial to complete destruction of the chlorophyll.

CILIATE. Fringed with hairs.

CLONE. All of the divisions and offshoots arising from a single parent. Clones arise vegetatively and are all alike genetically.

COLEOPTILE. The seed leaf of a grass plant forming a tube.

COLEORHIZA. The first root structure of the grass seed.

COLLAR. The outer side of a grass leaf at the point where the blade and sheath come together.

COMMON NAME. The name given to a pesticide by a recognised committee (e.g. American Standards Association Sectional Committee on Common Names for Pest Control Chemicals). Example: Glyphosate is the common name for Roundup.

COMPACTION. One of the major problems in turfgrass management. It is the reduction of the volume of pore spaces in a material.

COMPATIBILITY. Capable of acting together with reference to chemicals. Chemicals that can be mixed and still remain effective are considered compatible. An important characteristic to check before tank mixing.

CONCENTRATION. The amount of actual pesticide contained in a mixture to be applied.

CONIDIUM. (Pl. Conidia) An asexual spore that is produced externally at the end of a special spore bearing hyphae called a condiophore.

CONTACT HERBICIDE. A herbicide that kills only the plant tissue that it touches with very little translocation.

COOL SEASON GRASS. A grass whose optimum temperature range for growth usually lies between 18 and 21ﾰC.

CORING. A form of turfgrass cultivation that employs a hollow prong or core to remove a plug of soil.

CORTEX. A layer of cells between the epidermis and the vascular region.

COTYLEDON. The first leaf, or leaves that emerge from a seed plant.

CROP SEED. A term used on seed labels to denote any plant that is grown for profit.

CROWN. The part of the grass plant just above the ground where the tillers, stolons, and shoots join.

CULM. The stem of a grass plant that is earing a flower.

CULTIVAR. A horticultural variety that can be reproduced without losing its distinguishing features.

CYTOPLASM. The living material in a cell.