Respiration

The process by which plants use the energy stored from photosynthesis to develop and grow. The carbohydrates, which are formed by photosynthesis, are broken down in the presence of oxygen to form carbon dioxide and water, as well as the release of energy. This is the reverse of photosynthesis. Respiration has a higher optimum temperature than photosynthesis, which means that there is a net build-up of food reserves (via photosynthesis) before they are more rapidly consumed at higher temperatures and levels of cellular activity.

  Root Biomass

The total weight of plant roots. For research purposes this would normally be the total dry weight of roots.

  Root Break

A change in the uniformity of a soil creates a layering effect which results in roots growing horizontally rather than vertically. A root break can typically occur where distinct layers of top-dressing have formed within a soil profile; or at the junction of a layer of thatch and soil rootzone, or also at places of soil compaction which encourages roots to grow laterally rather than downwards. A typical root break might appear in cricket pitches at a depth of 35mm-50mm.

  Root Exudate

Fluids (secretions) from plant roots which can encourage beneficial bacteria or fungi in the rhizosphere. Root exudate can also help to protect plant roots from undesirable micro-organisms or toxic soil conditions. Exudates from cut tree roots, damaged by slit or chisel tining, or other means, can cause localised toxicity to grass roots. This can make the sward surface turn a reddish colour, from the bleeding of the roots, which in turn can start to thin the sward. A typical example of where this would be most noticeable would be on a golf green which is closely surrounded by trees.

  Root System

A network of roots within a soil that where abundant and with good soil contact creates a well anchored plant which produces a stable soil. A well-developed root system also helps to improve drought resistance, as well as withstand and recover from wear. A root system for a grass plant will initially consist of a primary root, the seminal root, which is then superseded by the main secondary fibrous roots.

  Roots

The underground growing part of a plant. Grass roots are fibrous and multi-branched. Roots can also be classified as Fine Roots or Structural Roots. Roots are an essential, yet unseen, part of a plant. They • provide anchorage for a plant, • take in water and dissolved nutrients from the rootzone, • act as food storage organs, and • provide an important environmental service in preventing soil erosion. There are different types of root variations, including aerial roots, e.g. Hedera helix (Ivy) and root tubers, e.g. Ficaria verna (Lesser Celandine).

  Scutellum

A feature of the cotyledon which absorbs nutrients from the endosperm during the germination process.

  Seed

The product from which turfgrass surfaces are mainly formed, either directly by seed sown onto an area, or by turfing (which will have mostly originally been sown from seed). Grass seed comes in different shapes and sizes, and colours.

  Seminal Root

The first, or primary, root which begins developing as soon as a grass seed germinates. The root can consist of one or more main roots, as well as root branches. The seedling and young grass depend entirely on the primary root system for water and soil nutrients. The seminal root survives only for a short period to allow the grass plant to start to become established, by which time other roots, which is termed the secondary root system, have developed and take over.

  Sepal

An outer feature of a flower, of which there are usually several sepals, which encloses and protects the remainder of the flower components. The collective term for the sepals on a flower is Calyx.