Lecture 2 - Irrigation Management for Agricultural Sustainability Glossary

Abscisic Acid (ABA)

Plant hormone causing stomatal closure

(PRD) Alternation

when irrigated and drying parts of the rootzone are swapped during PRD

Anoxia

Lack of oxygen (in the rootzone → inhibits oxygen-requiring respiration)

Anthocyanins

Chemical compounds giving leaves / berries a red colour

AWD

Alternate Wetting (flooding) & Drying of a rice crop

Green Fraction

Area (%) of soil surface covered by vegetation

PRD

Partial Rootzone Drying = irrigate only part of the rootzone

Remobilisation

Carbohydrates transported from a plant part (stems) to another (grain)

RDI

Regulated Deficit Irrigation = decrease / suspend irrigation at a certain time

Sap Flow

Movement of water from roots to shoots = the transpiration stream

SDI

Sustained Deficit Irrigation = decrease / suspend irrigation throughout season

Stomatal Closure

When guard cells lose turgor, so aperture between them decreases

Turgor

Pressure exerted by cell contents on the cell water – gives a plant structure

Tiller

“branch” of a cereal crop that produces grain

Transgenic

genetically modified plant