Agriculture Reference
In-Depth Information
producer
an organism which manufactures its own food from simple molecules e.g.
green plants through the process of photosynthesis
propagule
any part of a plant that can be used to create a new plant
pupa
resting stage of some insects such as moths
quiescent seed
a viable seed which does not germinate because the environmental
requirements (water, oxygen, a suitable temperature) are not present
response periods
when the plant/crop benefits from the addition of water
reversion
a return to a green-leaf condition in a plant selected for its variegated foliage
rhizome
a horizontal, generally underground stem which may act as a food storage
organ
rhizomorph
'bootlaces' produced by some toadstool fungi, that are able to infect plants
underground
risk
can be measured by the chances of something happening and the level of
consequence if it did
rose balling
rose flower buds fail to open when outer petals are scorched and killed
rotation
planting particular crops in different plots each year
runner
a stem that runs along the ground and produces new plantlets at the nodes
e.g.
Ranunculus repens
or at the tip e.g.
Fragaria
(strawberry)
sand
a soil particle between 0.06 and 2.0mm in diameter
saprophyte
an organism that lives on dead plant material (
see
decomposers and
detritivores)
saturation point of soils
when water has filled all the soil pores (i.e. no air in the pores); waterlogging
scarification
physically damaging the seed coat to break dormancy
sclerotium
a small dark-coloured clump of fungal tissue that enables some fungi to
survive for long periods
secondary root
see lateral root
seed
the structure that develops from the ovule after fertilization
self-pollination
pollen transfer between flowers on the same plant or within the same flower
semi-evergreen
a plant that retains some of its leaves through the year but may shed most
leaves under severe weather conditions
sexual reproduction
the formation of new individuals through fusion of male and female gametes
(sex cells)
shrub
a multistemmed woody perennial plant having side branches emerging from
near ground level
silt
a soil particle between 0.002 and 0.06 mm in diameter
soil horizons
specific layers in the soil that can be seen by digging a soil pit
Soil Moisture Deficit (SMD)
the amount of water required to return the soil to field capacity (FC)
soil structure
the arrangement of particles in the soil
soil texture
the relative proportion of the sand, silt and clay particles in the soil
species
a group of individuals within a genus which have characteristics in common
and are able to breed among themselves
spine
a sharp pointed leaf modified for defence and to reduce water loss
spore-case
a small fungal structure that contains spores
stolon
a long arching branch which roots at its tip to produce a new plant e.g. in
Rubus fruticosus
stones
soil particles larger than 2 mm in diameter
straights
fertiizers that supply only one of the major nutrients
stratification
moist storage of seeds in cold or warm temperatures to break dormancy
subsoil
the layer (horizon) below the cultivated layer (topsoil) and lighter in colour
because of its low organic matter level
succession
a sequence of changes in the composition of plants and animals in an area
over time.
