Greenhouse Management
Glossary
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WATER HAMMER – When water velocity in a flowing pipeline changes abruptly the pressure will spike so high that it can cause entire pipelines to explode, implode, or otherwise break. Water doesn't compress, is heavy, and has a lot of momentum at high velocities. Pipes with water running at high velocities are therefore at much higher risk for bursting due to water hammer. The bottom line is to open and close valves slowly and don't let water hit the end of a closed pipeline at high velocities.
WATER SOLUBLE FERTILIZER – Fertilizer that either comes in liquid form or comes in crystal form that is dissolved in water.
WATER TUBE BOILER – A water-tube boiler (also spelled water-tube and water tube) is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes.
WEED – Any undesirable plant or grass species; any plant growing where you don't want it.
WET FEET – When the soil in a container stays wet, plants may be referred to as having wet feet.
WETTABLE POWDER – Pesticide formulation of toxicant mixed with inert dust and a wetting agent that mixes readily with water and forms a short-term suspension (requires tank agitation).
WETTING AGENT – Any compound that causes a liquid to spread more easily across or penetrate into the surface of a solid by reducing the surface tension of the liquid.
WHITE WASH – A paint-like substance applied to greenhouse covering to mitigate high greenhouse temperature and reduce plant watering requirements.
WITCHES’ BROOM – A plant condition suspected to be caused by genetic mutation or a virus where all adventitious buds in a certain part of the plant start growing, resulting in a lot of tiny stems; abnormal brush like development of many weak shoots.
