Growth and Development of the Cotton Fruit

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Growth and Development of the Cotton Fruit

• Craig W. Bednarz
• University of Georgia
• Tifton, GA

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Cotton Flower Parts (complete)
Stigma
Style
Filament
Petals
Anther
Ovary (fruit)
Bracts
Ovules (seeds)
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Cotton Terminal (40 X)
Main Stem Leaf Primordia (whorl)
Main Stem Meristem (monopodium)
Fruiting Branch Meristem (sympodium)
Fruiting Branch Meristem
Consecutive Nodes (not visible) Thrips
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Cotton Sympodia
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Cotton Monopodia/Vegetative
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bract
sepal
whorls
petal
stamen
Carpel(pistil)
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Schematic of a Carpel in Cross Section
one carpel
Four carpels (fold then fuse)
axile placentation
parietal placentation
Weier et al., 1980
van Iersel and Oosterhuis 1995
pea
cotton, okra
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Cotton Pollination
Pollen Tube grows at a rate of several mm/h and
is SENSITIVE to EVERYTHING.
Tube enters mircopyle and male gametes are
released.
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Cotton Ovule on the Day of Anthesis
micropyle
0.008
Oosterhuis and Jernstedt, 1999
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Fiber Initials on the Day of Anthesis
0.001
Oosterhuis and Jernstedt, 1999
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Developing Cotton Fibers One Day After Antheis
0.001
Oosterhuis and Jernstedt, 1999
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Cotton Fiber Footing
Berlin, 1986
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Fibers Elongate for the First Three Weeks After
Anthesis (Boll Enlargement Phase)

• Fibers are Single Cell
• Increase in Length 1000 X
• Water Required
• Potassium Required
• Temperature

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Fibers Fill During the Second Three Weeks After
Anthesis (Boll Filling Phase)

• Water
• Potassium
• Temperature

Bill Goynes, USDA-ARS
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Stages of Boll Development
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What Influences Fiber Properties?

• CHO supply (source)
• CHO demand (sink)
• Water
• Temperature
• Nutrients

Also impact CHO supply and demand.
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CHO Supply
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CHO Supply
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Decreased Pnet and Increased Rdark results in

• Less weight gain.
• Less CHO availability for boll filling.
• Reduced boll weight.
• Reduced fiber mirconaire?

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CHO Supply
Premature aging of crop canopy should be avoided
(water stress, fertility stress, etc.). Will
impact early season storage of CHO or hasten
decline in Pnet
Boll filling occurs with a diminishing CHO supply
(root and petiole storage, etc.)
Bourland et al., 1992
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CHO Supply
Late Season Heat and Drought?
Short staple and low mike cotton early in harvest
season?
Hake et al., 1990
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CHO Demand
Hake et al., 1990
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CHO Demand
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Yield Distribution
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Yield Distribution
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CHO supply (environment) and CHO demand (crop
condition, maturity) impact fiber properties.