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Corn Growth Stages
VE - Emergence
V1 - 1st leaf collar
- Growing point above soil
- Tassel and ear shoots initiated
- Seed row set
V5-7
V12-16 - Kernels/ear (size of ear)
VT - Tassel (2-3 days before sinking)
- (Pollen lives 24 hours)
- (Pollen shed 1-2 weeks)
R1 - Silking
R2 - Blister (10-14 days)
R3 - Milk (18-22 days)
R4- Dough (24-28 days)
R5 - Dent (35-42 days)
R6 - Black layer (55-65 days)
(30- 35% moisture)
What is the base temperature for the growth of corn?
50
At what temperature does corn growth peak?
86
What is the formula used to calculate Growing Degree Days (GDD)?
GDD = (high + low) /2 - 50
What are mycotoxins?
Poisons produced by particular fungi under certain environment conditions.
Kinds of corn
Dent - Starch shrinks
Flint - Hard starch
Flour - Soft starch
Popcorn - Very hard, resists steam
Sweet Corn - Wrinkled, sugar
Waxy - Dull, starch quality
Pod - Primitive features
What is the progressive sequence of developmental stages of corn?
tassel, silking, milk, dough, dent, black layer
Yield loss from moisture stress is most serious at the _______ stage:
V12 - R1
Mycotoxins
- Mycotoxins are produced by fungi
- Aflatoxin is a greater concern then vomitoxin in livestock feed
- Mycotoxins can result in liver damage in livestock
- Avoid rotation corn where Fusarium stalk rot o wheat scab fungi has been a problem
Soybean Growth Stages
VE - Emergence
VC - Unrolled - unifoliate
V1 - First expanded trifoliate
V1-2 - N bacteria infect roots
V3-6 - Node location fist flower
R1 - First open flower
R5-6 - Maximum N fixation
R8 - Maturation - 95% pods mature color
Determinate Soybean
- Vegetive growth before flowering
- All flowers same time as plant
- Seed matures same time
- Terminal leaf same size
Indeterminate Soybean
- Vegetive growth continues
- Flowering continues
- Seed maturity varies
- Terminal leaf smaller
Nitrogen Fixation
A process in which nitrogen in the atmosphere is converted into ammonium.
Several factors affect the early development of soybean plants. What has the most influence on early season vegetative growth?
Temperature
What percentage of the flowers that develop on soybean plants can be expected to abort or fail to form pods?
65-75
Classes of Wheat
Hard Red
- Hard red winter (HRW)
--- High gluten, 12-13% protein
--- Use: all purpose flour
- Hard red spring (HRS)
--- High gluten, 14-15% protien
--- Use: bread flour
Soft Red
- Soft Red Winter
--- Low gluten, 10-12% protein
--- Use: cakes, pastries, crackers
White
- Hard White Winter (HWW)
- Soft White Winter (SWW)
--- Low gluten, 10-13% protein
--- Use: hard rolls, tortillas
Durum
- Low gluten, 15-16% protein
--- Use: pasta
Wheat seed head structures
Spike, Spikelet, Glume, Lemma, Palea, Floret
The spread and severity of disease is favored by what kind of weather?
cool and wet
Alfalfa hay Quality
Leafiness - attached
Maturity - pre-bud -> late flower
Texture - fine stems
Color - bright green
Odor - not musty
Foreign Material - sticks, dirt
Species - discount grass, weeds
Harvesting alfalfa for hay at the early bud stage rather than waiting to harvest at the mid-flower stage will
provide forage with higher digestibility
What abbreviation represents the feed value of alfalfa hay?
RFV
Total Digestible Nutrients
TDN
Acid Detergent Fiber
ADF
Neutral Detergent Fiber
NDF`
How does autotoxicity affect alfalfa seedlings?
affects root development and cause stunted plants
Autotoxicity
Alfalfa plants produce toxins that can reduce germination and growth of new alfalfa seedlings
Kinds of silage
- Corn Silage
- Earlage
- Alfalfa Haylage
- Oatlage
- High moisture shelled corn silage
Silage Process
Aerobic Fermentation Phase
- Sugars -> CO2, H2O, heat (respiration)
- Oxygen is depleted
Anaerobic Fermentation Phase
- Bacteria conver sugars -> lactic acid
- pH -> 4
Harvest
- Determines Quality
--- Crop Stage
--- Moisture
--- Frosted Corn -> appears dryer
--- Drought
Saftey - Silo gases
- Carbon Dioxide - odorless, colorless, heavy
- Nitrogen Dioxide - "bleach" odor, yellow/brown
Feedout Phase
- Air exposure -> mold
- Even feeding face (bunker)
Silage Quality
Stage of Maturity
- corn, hard dough
Dry Matter
- Upright (60-65% moisture)
- Bunker (65-70% moisture)
- Bag (60-70% moisture)
Grain Content
- 50-60% energy in grain
Silage Cut
- 1/4 - 3/8 inches, "clean" cut
Color
- light brown/some green
Odor
- clean, sharp
Carbon Dioxide
colorless, odorless, collects in lower part of silo, heavy
Nitrogen Dioxide
brown, yellowish, has burning sensation
Bacterial Inoculants
Putting in more bacteria
Nonprotein Nitrogen
Increase crude protiens
Packing and sealing silage properly is important to keep good quality silage during storage because it:
excludes oxygen
What is the recommended moisture content at harvest for corn to be ensiled and stored in horizontal (bunker) silo?
65-70%
High levels of nitrates in corn silage can be toxic to livestock. Which management practice will reduce the risk of high nitrates in the silage?
Increase the cutting hight and harvest on sunny days
The primary function claimed for bacterial inoculants used as silage additives is to
increase fermentation rate and efficiency
During the anaerobic phase, sugars are converted to ____ acid with a ____ pH.
lactic and 4
Oilseed Crops
ex: Flax, Safflower, Canola, Sunflower
- Cooking oil for food (feed by-product)
- Oil characteristics (fatty acid make up) quality
Pulse Crops
ex:Dry pea, Lentil, Chickpea
- Seed of legume crops for food/feed
- Legumes - compounded leaf, taproot
- High protein, high quality
- Local protein supplement crop (peas)
The oil extracted from flax for use in paints called ____ oil
Linseed
Which fatty acid is monounsaturated and contributes to characteristics that make it a high quality cooking oil
Oleic
Soil temperature at 2 inches should be about ___ before planting soybeans.
55 degrees
At indeterminate growth habit soybean ______.
continues to flower and grow vegetatively simultaneously
The primary function claimed for bacterial non-protein inoculants used as silage additive is to ____.
increase fermentation rate and efficiency
Autotoxicity in alfalfa production is the result of toxins from _______.
the alfalfa plant itself
Which alfalfa hay harvest method has the highest field loss associated with harvesting?
Field cured hay in bale
Autotoxins in corn can affect livestock by causing
liver damage
What is the best quality corn silage
corn grain content contributes at least 50% of the energy
What has the greatest influence on flower imitation in soybean?
Day length
What is the most undesirable quality for cooking oil?
low smoke point temperature
What fatty acid is consider the most desirable in cooling oils and food products?
Monounsaturated
V-1 growth stage in soybean means the plant _____.
has first trifoliate leaf
_____ increases the risk of nitrate toxicity in corn silage.
Drought
Special crops like safflower and chickpea
are broadleaf crops that fit well in rotation with small grain , grass type crops
Tan spot disease of wheat overwinter primarily
on where stubble residue