Addressing Real Weed Science Needs with Innovations

Abstract

Weed science is responsible for reducing weed competition with crops, within constraints, allowing food production for a growing world population. We have been successful, but with an increasing reliance on the fantastic arsenal of herbicides. Heavy herbicide usage and the concomitant loss of control due to changing weed species spectra, as well as evolved herbicide resistance, along with cancellations of registrations, limit chemical options. Old “innovations” such as well-conceived rotations and various mechanical procedures partly alleviate chemical dependency. We must try innovative, meaningful herbicide mixtures, whether synergistic or additive, mixtures of crop varieties, more competitive varieties, including allelopathic varieties, which could all help to lower chemical dependency. Three cases where innovative genetic-engineering coupled with chemistry seem to be needed are: (a) for the control of parasitic higher plant weeds such as broomrapes (Orobanchespp.), dodders (Cuscutaspp.), witchweeds (Strigaspp.) that cannot be controlled by mechanical or selective chemical means with a sufficient margin of user error; (b) for the control of weeds in wheat (Triticumspp.) that are evolving multiple and cross resistances toallwheat-selective herbicides; and (c) to replace the majors-triazine and chloroacetamide herbicides in corn (Zea maysL.) that are under attack and where many local restrictions and cancellations have been imposed. We need better replacements than the resistance-prone inhibitors of acetolactate-synthase and acetyl-CoA-carboxylase. Much of the long-term innovative planning and research must come from the public sector as no one else seems willing to fill the needs.