Sweet Corn and Popcorn by AXqfHz8


									Sweet Corn (Zea mays var. rugosa)
                     Key points:
                         Difference from
                          other corns
                         3 categories of sweet
                         Wind pollination and
                          its implications
                         Succession
                         Problems
Sweet Corn is unlike other corns

                      _________________
                          Produces and retains
                           large amounts of sugar in
                           the kernels, rather than
                      Pericarp
                          The skin of __________
                           is thinner, making them
                          Seed is wrinkled when

 Sweet corn seed
Types of Sweet Corn
   ____________ cultivars
       Contain the “sugary”
        gene (su)
       Have less initial kernel
        sugar than other sweet
        corn types
   Sugary enhancer
       Contain the
        (se) gene
       Significantly raises the
        sugar content above
        standard cultivars
       Taste, tenderness, and
        texture are outstanding
Types of Sweet Corn
                     Supersweet cultivars
                         Contain the “shrunken-2”
                          gene (sh2)
                         Much initial R & D was
                          done at University of
                          _______ in 1950s
                     Hold sweetness longer
                      than su or se types
                         Kernels have a crispy,
                          tough-skinned texture
                         Require ______________
                          soils for germination than
                         Must be isolated from
                          other types of corn
                          ______ at same time
Sweet Corn: Planting
   To have sweet corn throughout the summer
    must have succession plantings
       Use both __________________ timing (temporal)
        and cultivars with different maturity
       Example of a planting regime
            First planting (varietal succession)
                  _________________ crop cultivar
                  Main crop cultivar
            Second planting (temporal succession)
                  Same cultivar when three to four leaves have appeared on
                   the seedlings in the previous planting
Sweet Corn Reproduction
   Flowers
       Separate male and female flowers on each
            Which is which?
Sweet Corn Reproduction
    Male flowers are tassels
         Spikelets contain ____________ , which
          produce pollen

                              Branch of tassel
Sweet Corn Reproduction
    Female flowers are ______________
         Each potential kernel produces a silk, on which
          the pollen lands for fertilization
Sweet Corn
   Plants have a
    tendency to produce
    or “tillers”
       Don’t really need to
        be removed; can’t
        compete with main
Sweet Corn: Pollination
   _______________ pollinated
      Plant sweet corn in _________ of at least four
       rows to ensure good pollination
   Cross-pollination
       Prevent from cross pollination by field corn,
        __________________ corn, or popcorn
            Especially supersweet cultivars because if pollinated by
             other corns they will not develop high sugar content
       Cross pollination between ___________ and white
        cultivars will affect appearance of white corn
Sweet corn – cross pollination
   Cross pollination
    between yellow and
    white __________
    will affect appearance
    of white corn
       Yellow color – most
        common in midwest
       _________ (“butter and
        sugar”) - common in
       White – local popularity
       Specialty types – i.e. blue
Incomplete pollination
                   Incomplete __________
                       Lack of tip fill
                       Blanking
                       Causes
                            Not planting enough
                             sweet corn
                            Lack of moisture
                            Hot weather
                            Inadequate fertilizer
                            Birds
                            Insect feeding on silks
Sweet Corn: Harvesting
                     Ears should be picked
                      during “_______ phase”
                         Juice of the kernel
                          appears ______, not
                         Occurs ~20 days after
                          appearance of first silks
                     Harvest time indicators
                         Drying and ___________
                          of the silks
                         Fullness of the ________
                         Firmness of the
                          unhusked ears
        Sweet Corn:

   Corn ______________
       Once caterpillar is
        ________ husk,
        there is no effective
       Bt or mineral oil on
        young silks may help
        prevent entry
            Can insert
             _____________ gene
             for Bt protein into
             sweet corn
      Sweet Corn:

   ___________ beetle
      Carry Stewart’s

          Yellow streaking of
           leaves, ___________,
           plant death
          More severe in
           southern IL
Sweet Corn: Problems
   Smut
       Caused by a ________
        that invades kernels or
       More severe in hot,_____
        conditions and with white
       Culinary delicacy,
        especially in __________
            Called cuitlacoche
            Can cause contractions
             in pregnant women
Sweet Corn: Problems
                    Raccoons
                        Raccoons eat sweet
                         corn when it is in the
                         early ____________
                         phase, just before
                         the ears are ready to
                        Hard to control
                             ____________ can be
                             Watch for tracks

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