Testing Herbicide Tolerance

Testing Herbicide Tolerance

1. Testing on Seeds

   • requires approx. 300 seeds
   • Pot Test
     • seeds sown in pots
     • herbicide introduced to seedlings at during the leaf stage weeks 2-3
     • Plants are assessed 3-4 weeks later
   • Petri Dish Assay
     • seeds germinated in herbicide solution
     • growth reported after 14 days
     • Relatively fast and low in cost compared to the pot test

2. Testing on Plants

   • Herbicide reisitance can be tested once the plant has grown
   • Syngenta Quick Test
     • test takes approx. 4-6 weeks
     • requires 50 plants and to be conducted during growing season
       • not appropriate for this scenario
     • cuttings from sample plants are treated with a herbicide spray
       • herbicide applied to a growing plant means it mimics field conditions
   • Molecular Testing
     • faster than petri dish assays but more expensive
     • leaves of plants are tested in a lab for specific mutations or transgenes known to confer with herbicide resistance

3. Radio-labelled lab tests

   • most expensive test but also fastest
   • plants collected from field and the rate of metabolism of radio-labelled herbicide leaves is measured
   • can be bias due to what plants are selected