Throughout my time in the primary industry, of which is some 20+ years now. OWR has been at the forefront as one of the most debilitating diseases that intensive onion production areas face. Even with average crop rotations of 2 crops in 5 can still lead to OWR becoming the norm.

Even new land can be hit hard by OWR, the block may have had onions fed to stock some 20 years ago.

Much work has been done on solutions to bring OWR under control, this is no easy task. Much reliance has been on chemicals. Of which a few chemicals have ceased having efficacy (Sumisclex, Folicur), it makes the battle that much harder with less available chemicals.

To prevent resistance and to enable active ingredients to help growers have good efficacy for years to come, and to keep the production of onions financially viable.

At the present time, there are 3 products being used in chemical programs for OWR, these are triadimenol, Luna-Devotion and Pristine. A key is that we have two modes of action with these three chemicals. Taking this into account, when looking at chemical programs to combat OWR, it is vital that we look to alternating modes of action and chemicals within these modes of action.

This is a challenge in itself, taking into account we have three chemicals and two modes of action.

At this point in time, for the next few years, this is the chemistry our onion industry has. I have a fear that if in fact we get resistance to these active ingredients, our ability to grow onions financially will be hit seriously.

These are just a few thoughts on the topic, there are many for sure. I ask, please take into consideration the modes of action when putting together your OWR spray program, work with you OWR growing degree day calculators, aim for first application at the 80 – 100 days, not more, this will start the season off in the best possible position.

Join the conversation, we need much discussion on OWR and the options that are available to our industry.

Be great to hear some thoughts and discussion on this topic