Sep 15, 2017

Powdery Mildew: Chemical Controls

Some of our past posts have looked at cultural and biological controls for powdery mildew. These, along with GreenCure, are all typically approved for use in certified organic agriculture.

Now, it’s time to talk dirty. So, get out your PPE (personal protective equipment), take a deep breath, and prepare to kill some bacteria and fungi…

Synthetic chemical fungi killers come last in this series because, ideally, they are the last resort. While undeniably useful components in an integrated disease management plan, they should not be relied upon as a substitute for good gardening practices.

Dropping Bombs

You may be familiar with foggers or “bug bombs” for pests like spider mites. They also exist for fungal diseases. Trinity TR‘s active ingredient is Imazalil. TR stands for total release. Once you trigger the fogger, the entire contents of the canister are emptied. One small two-ounce fogger treats up to 1,500 square feet (1,000 square feet for powdery mildew). As with other bombs, thoroughly read and follow all directions on the label. The fog is flammable so make sure there aren’t any open combustion sources, like a pilot light. Once the treatment is over, ensure ventilation has completely removed the product from the space before reentry. We recommend airing out your grow space for a minimum of 24 hours to protect you and your pets from harmful fumes.

Fungi bombs work very well as a preventative measure when preparing a new garden or treating a space that previously contained pathogenic spores. Foggers provide excellent coverage over a large area and won’t leave residue behind, as burning sulfur tends to do.

Use with Caution

While Trinity TR can be used in a garden while plants are in it, be careful. Do not trigger a bomb too close to your plants or they may cause damage. In the Keys to Success listed by the maker of the product, it says to “clear out a three-foot area around the canister to prep for application”. Remember, one small can is intended to treat 1,000-1,500 square feet which is larger than many indoor gardens. If used in too small of a space, the increased concentration could also cause damage to your plants.

The More You Know the Better You Grow!

Integrated pest/disease management is a prevalent theme in agriculture. It is a very broad topic and one that keeps coming up (perennial in nature, if you will) for good reasons. As the use of the word ‘integrated’ suggests, no single action or product will, by itself, guarantee victory in the fight against powdery mildew. Long-term success comes from a combination of techniques, products, and, of course, hard work.

That brings us full circle in our look at ways to grow in harmony with powdery mildew spores. While there are many gardening approaches and products when it comes to fungal diseases, we’ve taken a look at some of the most effective. If you missed our previous posts, visit our blog page to learn more.

When it comes to fighting garden diseases like the phantom menace that is powdery mildew, may the spores not be with you!