Hybrid and Variety Selection Flashcards Preview

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Flashcards in Hybrid and Variety Selection Deck (11):

prmary method of avoiding yield reductions due to pests

  • selecting hybrid with pest resistance / tolerance


herbicide tolerance and sensitivity

  • preclude use of certain herbicides (high sensitivity)
  • can allow use of others (low sensivity)



  • ease / efficiency of the harvest
    • minimizing harvest losses
    • minimizing damage to harvestable part of crop during harvest process are important


End Use

  • important becuase varieties hybrids developed for certain reasons


Value added Trait

  • improved nutritional value can make crop more valuable


Transgenic Crop

  • genes in species have been altered through insertion of foreign genetic material



  • genes have been modified by natural mutation or mutation due to exposure /  radiation or other factors
    • GMOS not same as parents 
    • includes transgenic crops


Advant of GMOS

  • Improved resistance or tolerance to insects and diseases
  • crop tolerance to herbicides 
  • safer pesticides
  • improved crop quality nutritional value
  • yields may or may not be improved


Limitations of GMOS

  • lack public acceptance marketability
  • reduced yield
  • potential to trnasfer herbicide resistance to weeds
  • increased pest tolerance to source of pest resistance


LSD values

  • LSD = least significant difference
  • used to determine if two means of yield (or other variable) are different from a statistical standpoint
  • how it works
    • value is given for the LSD
      •  the difference between 2 yield means must be larger than LSD for the 2 yields to be different at a given probability level (95%)
      • Example
        • yields of A, B, and C are 50, 67, and 54 bushels/acre
        • LSD is 5 bushels / acre
        • Yields of A and C considered the same
        • Yields of B significantly bigger than A or C


Crop Variety Protection Laws 


  • variety must be new to be protected
    • (not previously sold) 
    • distinct, unique characteristics
    • uniform, same characteristics within seedlot
    • stable (can reproduce with same characteristics
  • Protected varieties cannot be sold, traded, exported, or used in new varieties without permision of owner
  • 3 Exemptions
    • USDA can remove protection
    • protected varieties can be used in research
    • farmers can save protected seed and use in farming operation