Greenhouse Management
Glossary
B
BACILLUS THURINGIENSIS – A bacterium used as a biological control agent for many insect pests.
BARE-ROOT – A plant with little or no soil around its roots; deciduous plants and small evergreens are commonly sold bare-root.
BASE – Something that will neutralize an acid, such as hydroxide or limestone.
BAGASSE – Bagasse is a waste bi-product of the sugar industry. It may be shredded and/or composted to produce a material which can increase the aeration and drainage properties of container media.
BALLED AND BURLAPPED – The roots of the plant have soil attached and are held in place with burlap or some other material.
BARE ROOT – The roots of the plant are bare, with no soil.
BIENNIAL – A plant sown one year to flower or fruit the next, then dying or being discarded. Many vegetables are biennial, but are treated as annuals and harvested in their first year before they have flowered.
BIODEGRADABLE – Subject to biological decomposition into simpler biochemical or chemical components.
BRITISH THERMAL UNIT (BTU) – The amount of heat required to raise the temperature of one pound of water one degrees F at or near its point of maximum density.
BULB – A resting stage of a plant that is usually formed underground and consists of a short stem base bearing one or more buds enclosed in fleshy leaves and buds (e.g., tulip, daffodil, etc).
BULK DENSITY – The mass of dry soil divided by the bulk volume. Bulk density is not an absolute indicator of compaction because root limiting density varies with texture. Root extension is generally limited by bulk densities >1. 6 g/cm in silt loam soils; 1.6 g/cm is unlikely to be limiting in sandy soils and is severely limiting in clayey soils.
