Abstract:
Weed resistance is usually diagnosed after a weed control practice has lost
efficacy and weed populations begin to increase rapidly. Prediction and validation in
the field at a very early stage of resistance development is a promising method for
preventing an uncontrollable problem. Pattern-thinking helped individuals connect their
experience of weed infestations with development of weed resistance. Field
representatives connected early verification with immediate management to reduce the
potential problem of weed resistance.
A method for rapid detection of weed resistance by microcalorimetry was
developed to distinguish between herbicide resistant and susceptible biotypes. This
general method was used to test three different weed species and three different
herbicide modes of action. Heat evolution as a product of plant respiration by samples of meristematic tissue was compared between resistant and susceptible biotypes. The
procedure readily distinguished between biotypes.
Since microcalorimetry provided quick and accurate results, all field
representatives stated that the combination of pattern-thinking and rapid assay would
improve management of weed resistant populations. The combination would improve
visual detection based on the standard growth and development model for weed
resistance and population growth. Also, biological verification using microcalorimetry
provides immediate feedback and validation of weed resistance. Thus, early detection
of weed resistance is a very important tool which will assist farmers in dynamically
managing weed infestations.
