2/23/2021

Plant growth regulator (PGR) overdose of a geranium.

A career spent working with growers has given me the unique privilege of seeing numerous, beautiful crops of all types. Despite their best efforts, even the greatest of growers will have a moment when Murphy’s Law affects a crop. Some of the most stressful experiences occur when plants are showing symptoms of some type of toxicity.

I have seen a wide variety of toxicity effects on crops:

• Overdose of plant growth regulators (PGR’s),
• Unexpected phytotoxicity from crop protection products,
• Mistakenly drenching crops with herbicide instead of a fungicide and
• Ill effects from preemergent herbicides.

Whenever we identify symptoms of toxicity in our plants we take quick actions to overcome the damage done in an effort to produce a saleable crop.

In horticulture we have certain catchphrases to describe our efforts to reduce the toxicity in the soil, such as, “dilution is the solution to pollution” and, “when in doubt, leach it out!” This is an important step in helping to recover the crop. We want to try to help the crop overcome the intoxication by softening growth using a number of different tools available to the grower.

• We will grow the crop warmer to speed growth.
• Fertilizers that promote soft growth such as ammoniacal nitrogen and urea are applied.
• Extra phosphorus may be applied to encourage stretch.
• We also may employ a plant hormone such as gibberellic acid (GA) to soften growth and encourage stretch.

All of these steps are helpful and important. However, they are limited if the toxic substance remains in the soil and continues to damage the crop. PGR’s and herbicides can bind to plastic pots and trays and certainly can become bound in soil.

We have a product called Activated Charcoal, which is very helpful in these situations. Activated Charcoal is a liquid suspension of … activated charcoal. If you are dealing with a plant toxicity situation due to soil contamination, this product is a key tool to eliminating the root cause of the problem. Drenching your plants with Activated Charcoal will bind the toxic substance and help remove it from the soil.

Drenching with Activated Charcoal won’t undue the damage already done to the crop. However, by removing the cause of the problem from the soil, it will prevent the damage from progressing and allow you to overcome the damage with the other actions mentioned.

Accidents happen to all of us. It’s not a question of if it will happen but when. For this reason alone, it’s a good idea to keep a jug of Activated Charcoal handy so you have it available as a tool to help save your crop, should it become necessary.