Test 4 Flashcards
History of wheat
10-12,000 years ago
origin- SW Asia
cultivated wheat species
common wheat- triticum aestivum club wheat- " aestivum sub-species compactum durum wheat- " durum spelt wheat- " spelta emmer wheat- " dicoccon wild emmer wheat- " dcoccoides poulard wheat- " turgidum polish wheat- " polonicum persian wheat- carthlicum oriental wheat- " turanicum einkorn wheat- " monococcum timopheevi wheat- " timopheevii
2 types of seedhead morphology
awnless (beardless)
awned (bearded)
USDA classes of wheat
hard red winter wheat- main bread flour, most acreage in US
hard red spring wheat- bread flour, colder climates
soft red winter wheat- blends, biscuits, pancakes. SE & E US
duram wheat- pasta. creamy yellow flour. dakotas and canada
white or club wheat- fine pastries and blends. soft and hard. pacific NWo
Botany
cool season annual
vernalization (cold treatment during seedling stage to trigger reproductive growth)
spike inflorescence
2-15 tillers depending on species, variety, plant density, N
Feeke’s Growth Stages
1-8 vegetative
1: Germination and seedling: emergence through 3-leaf stage
2-4: Tillering: tillering begins, 4th leaf on first tiller
5: Tillering: tillering ends, plant starts upright growth
6: Jointing: first node visible at base of stem
7: Jointing: second node visible
8: Jointing: flag leaf visible, still rolled up. Spike beginning to swell
Feeke’s Growth Stages
9-11.4 reproductive
9: boot: ligule of flag leaf just visible
10: boot: flag leaf sheath completely out. Spike swollen but not visible (full boot)
10. 1-10.5: heading: first spikes just visible to all spikes out of sheath (full heading)
10. 5.1: heading: beginning of flowering
10. 5.4: heading: flowering over: kernel watery ripe
11. 1-11.3: ripening: grain progresses from milk to soft dough to hard dough
11. 4: ripening: ripe for cutting. straw dead
Establishment
seeded Oct grain drill 1.5-2 bu/acre prepared seedbed conventional or no-till 26 seeds/sq ft = 1.13 million seeds per acre
planting
Rates: 65-105 lbs/acre seed depending on %germination, seed size, broadcast or drilled, grazing benefits desired
Dates: mid-Sept. - early Nov.
Depth: 3/4 - 1 1/2
Row spacing: 4-8 in
Methods: drill, broadcast, aerial seeding into cotton or soybean when leaves are about 50% yellowed in Sept.
Planting
Rates: 65-105 lbs/acre seed depending on %germination, seed size, broadcast or drilled, grazing benefits desired
Dates: mid-Sept. - early Nov.
Depth: 3/4 - 1 1/2
Row spacing: 4-8 in
Methods: drill, broadcast, aerial seeding into cotton or soybean when leaves are about 50% yellowed in Sept.
Variety selection
look at regional variety trials
plant 2 or more with differing resistances to common diseases in the region and maturity
shop around
consider Hessian fly resistance if problem in region
consider test weights, lodging resistance, yield, winter kill, disease reactions
good agronomic practices
Fertility
P,K applied in fall pre-plant ASTR N applied at Feeke's 3-5 Rates 60-135 all at once or split S potential on sandy leachablee soils with low OM Lime: pH limit 5.7 chicken litter: 2-4 tons/acre in fall
Main types of diseases
rusts (stripe, stem, leaf) blotches (leaf, glume) mildews (powdery, downy) virus (barley yellow dwarf, wheat streak mosiac) others (take all)
Rusts control:
leaf and stripe most destructive in mid-south
symptoms show up April
some varietal resistance available
protection of flag leaf critical
Disease management strategies
select several different varieties esp with resistance to leaf and stripe rust
keep fields from ponding
don’t over fertilize N
scout (proper ID of any disease essential)
watch weather forecasts
proper and timely application of fungicides
fungicide application
needed when disease threatens flag leaf and favorable weather sets in (stripe rust likes wet weather and temp 50-65)
best time to apply is flag leaf (F8)
fungicide for leaf and stripe rust: combine propiconazole or tebuconazole + strobilurins
timing critical- don’t wait past F9p
insects
aphids armyworms cutworms grasshoppers Hessian fly scout in critical growth and season of outbreak timely use of approved insecticide
Hessian fly
Major pest maggot kills wheat seedling in fall select high yielding varieties with some resistance to fly destroy volunteer wheat in summer and fall rotate crops light tillage of wheat stubble plant after 'fly free' date (oct 16) dont over fertilize N
Main weeds
winter broadleaf annual ryegrass wild garlic know your weeds control early be aware of herbicide resistances
weed control options
Pre-emergence: Hoelon
Early post: sencor, axion, beyond
Post-emergence (as needed): axial, 2-4D LVE + dicambia, express, osprey, powerflex, finesse, harmony
Annual ryegrass control
becoming major problem
start with clean field
multiple herbicide applications of diff modes of action needed
consider delayed planting after tilling and using tillage and or burndown herbicides to kill first flush that emerges
use fall applied herbicides and action or it will be too late
Axiom + prowl, Axiom + zidua, anthem flex
resistant to Hoelon(95%) ALS herbicides(50-60%)
non-resistant: axial xl (tank mix harmony), powerflex, osprey
drainage
smoothing equipment alternative to precison (land planes, floating equipment, small scrapers and blades)
drain furrows: install at slight angle to field slope but not perpendicular
continuous positive grade along furrow
avoid berm remaining on upslope side
end furrow at unrestricted outlet point
install outlet structure (pipe) if needed
maintain existing outlet structures
maintain drainage ditches
precision grading best if feasible
hybrid wheat
male-sterile (female, seed plant) X male fertile
fertility restoration gene techniques similar to grain sorghum
can increase yields 20%
taller stalks, lodging prone
rye
bread flour, beverages more northern dark flour grown similar to wheat, fall or spring grazing. hay. silage second most common bread flour winter hardy, tolerates infertile soil seedhead susceptible to ergot fungus so not suited for humid south early maturing, good straw crop est mostly for grazing mid-south
