Resistance Management: Tracing its Evolution

- Franz Brandl

Resistance management is a hot topic, and it’s something that’s evolved a lot over the years. Twenty years ago we used single active ingredient products (or maybe we combined two) that were applied to the seed. The industry began with fungicide treatments, then added insecticides.

Today we have also added nematicides, and now use up to seven or eight (or more) active ingredients in one seed treatment product — something known as multiple modes of action. Seed treatment products become more complex as the challenges farmers face become more complex.

People have been attempting to control crop pests since the beginning of agriculture. Building on the methods that farmers have integrated into pest management practices on their farms, scientists continue to develop new ways to control diseases, insects, nematodes and weeds in crops.

New products add additional modes of action to manage resistance buildup. An example is a new active ingredient used in corn seed treatments — thiabendazole shows powerful activity against a broad spectrum of early-season diseases. It’s combined with three proven fungicides — metalaxyl-M, fludioxonil and azoxystrobin — to bring growers effective early-season disease protection in corn.

Seed treatment is such a convenient technology that farmers now demand these multiple modes of action to help manage resistance buildup, and the industry must respond.

As a result, some mistakenly believe that multiple modes of action mean you’re always covered for everything. There is no magic bullet. You still must choose the right product with the right modes of action for your specific needs.

Space on the seed is limited. What we promote is the product, but what the customer supplies is the recipe, and the recipe consists of product, plus seed coating polymers, plus colorants. The seed coating polymer plays an important role in holding all the active ingredients on the seed, and these polymers are evolving in order to allow us to hold more product on something as tiny as a seed.

Adding biostimulants and micronutrients that mitigate environmental stresses are the next frontier to help manage resistance buildup using seed-applied solutions. This is a continuously evolving technology, and as it becomes more sophisticated, stewardship and proper training in the product’s use becomes key.

I’ve been privileged to be part of a global network dedicated to addressing the needs of recipe development, application technology, training and stewardship, product marketing support and seed safety.

It will be fascinating to see these products evolve over time, and the challenges that come with that evolution will need to be dealt with. Using knowledge gained in the past, the industry is poised to tackle them head-on.