Allelopathy of Coronilla varia

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Allelopathy of Coronilla varia

• Megan Hedlund
• Lycoming College
• Independent Study
• 1997

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What is Coronilla varia?

• Common name Crown vetch
• Used as a common roadside cover in the N.E.
  United States
• Perennial, leguminous
• Pinkish-white, pea like flowers that bloom
  throughout the summer
• Spreads rapidly

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What is allelopathy?

• Any direct or indirect (harmful or beneficial)
  effect of a plant, including microbes, on another
  plant through the release of chemicals that
  escape into the environment. (Rice, 1984)

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Allelopathic chemicals

• phenols (common in all plants)
• flavonoids (common in all plants)
• alkaloids (present in Coronilla varia)

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Experimental set-up

• Species tested Rumex obtusifolius, Barbaria
  vulgaris, Cirsium arvense, Poa pratensis, Thalspi
  arvense, and Solidago altissima
• 270 pots
• 10 seeds in each pot, all of the same species
• 45 pots per species, divided into 3 groups

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How were the six species tested?

• Collection of crown vetch from the field and
  frozen at 0o C
• Infusion made from leaves
• 50 g of thawed leaves
• 1 L of deionized water
• steeped for 24 hours at room temperature

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Two types of infusion

• Filtered after steeping for 24 hours, the
  infusion was filtered with a .45 micron filter to
  remove any bacteria or fungi
• Non-filtered after steeping for 24 hours,
  infusion was decanted off
• Infusions were refrigerated until used and used
  within 4 days

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Treatments

• Pots were randomly assigned to one of the three
  treatments
• Treated every four days, after watering
• Experimental pots recieved 10 ml of filtered or
  nonfiltered infusion
• Treatments ran for a 4 week period (total of 7
  treatments)

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Procedures

• Pots were monitored daily for germination
  recording began with the first day of planting
• End of 4 weeks each germinated plant was
• harvested
• weighed
• leaf area taken

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Speed of germination calculated

• Formula used
• SN1/1N2/2N3/3Nn/n x 100
• N1, N2,Nn are the proportion of seeds
  germinating per pot, each day (Ahmed, 1994)

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Results

• Based on these results, Coronilla varia does not
  appear to slow germination, but is beneficial to
  the growth of these species, significantly for
  Rumex obtusifolius and Poa pretensis.
• Results also show that naturally occuring
  microbes had no significant effect on germination.

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Plans for next project

• Make infusions from early and late season crown
  vetch leaves testing it on the same species
• Planting of my own crown vetch, allowing it to
  germinate, then planting species around it

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I would like to thank

• Dr. Michelle Briggs
• Lycoming College