Transcript Crop Structure and Development

Crop Structure and Development
Montana Small Grain Guide
Crop Structure
 Roots: anchor plant, absorb water &
nutrients
 Seminal Roots: first to emerge from
embryo, function throughout plant life
– can have 3 to 6 seminal roots
 Crown roots: originate from lower node
of the main stem and tillers
– each tiller has crown roots
Crop Structure
 Culms (stems): support for leaves and
heads
– one culm, plus additional tillers
– divided into nodes and internodes
 Leaves: photosynthesis
– each node produces one leaf
 Sheath: part of leaf wrapped around the
stem
 Blade: visible part of leaf
Crop Structure
 Collar: thickened part where blade joins
collar
 Ligule: protective tissue within sheath at
the collar area
 Auricles: appendages at the base of the
leaf blade
 Presence, size and shape of Ligules and
Auricles used in plant identification
Crop Structure
 Flag Leaf: top leaf, stays green longest, may
account for 80% of the filling of the grain
 Heads: where seed is produced
Wheat Head has several spikelets that
contain 2-6 florets (usually only 2-3 produce
seed)
Barley Head has 3 spikelets
6-row barley: each spikelet has one fertile
floret
2-row barley: only center spikelet has a
fertile floret
Crop Development
 Growing Degree Days: average of
minimum and maximum daily temps.
Minus base temp (37 deg. F)
– ex: temps = 40 and 58
– avg. = 98 / 2 = 49
– 49 - 37 = 12 GDD
 Emergence usually 50% complete at 85-
100 GDD
Crop Development
 Tillering begins at the 3 leaf stage
 Ideal conditions, new tillers formed at the
formation of each new leaf after 3 leaf
stage
 Stress will cause plant to skip some
tillers
 Germination: 35 - 40% soil moisture
– min temp 34-36 degrees
– optimum temp 59-65 degrees
Tillering
 May start 7 days after emergence
 Factors affecting tillering: large seed size,
high soil fertility, physical condition of
soil, optimum soil temp, optimum water
content, relatively low density of plants
 2-6 tillers per plant common
 Tillering stage lasts about 4 weeks
Jointing Stage
 Follows tillering, rapid growth period
(boot stage, shooting)
– stems and leaf sheaths elongate rapidly
 Lowest internode lengthens first followed
by next highest etc.
Heading
 “Boot” as the head grows, it enlarges the
sheath of the flag leaf
 Main stem develops first, followed by
tillers in order of origin
 Uppermost stem continues to lengthen
until head is above flag leaf
 Flowering begins a few days after head
emerges
 Ripening 25-40 days