A glance at isotherapy to control weed germination

Summary

Currently more and more research is being done on integrated weed management toreduce or avoid herbicide use. Some growers are already using isotherapic dilutions tocontrol weeds in organic farming. Isotherapy is different from homeopathy because it usesdiluted and potentized (succussed) solutions of alcoholic macerate of the very pest causinghealth troubles. We set up a germination experiment to test if isotherapic dilutions of leafmacerate of annual ryegrass affect the dynamics of its seed germination in Petri dishes. Ourresults were diverse, from no effect to 10% more growing degree days necessary to reach50% germination. It is doubtful that so low an effect will contribute to integrated weedmanagement unless the slightly delayed germination triggers secondary effects at otherlife stages. This is in accordance with the scientific literature on that topic: two-fifths of thereports showed no effect, two-fifths resulted in positive responses and one-fifth had diverseresponses for the criteria tested.