Dipping Unrooted Vegetative Cuttings to Reduce Incoming Pest Populations

Posted by Brian Sparks|February 6, 2024

One of the best ways to start off a new year in the greenhouse is to clean and sanitize benches, floors, and equipment. However, these efforts can feel futile when pest insects hitch a ride on unrooted cuttings and rooted liners. We know from prior research that any plant material entering the greenhouse is likely to have a small number of pests. These pests are difficult to detect and often possess some level of pesticide resistance. What if there were a way to suffocate any pest insects on the plant material coming into the greenhouse to have a better start?

A recent eGRO alert highlights how Canadian scientists began investigating dipping unrooted vegetative cuttings a dozen years ago. The technique was refined about five years ago with a series of trials performed by Dr. Rose Buitenhuis (Vineland Research & Innovation Centre) and 73% of Ontario growers began dipping their incoming cuttings in 2022. This technique is gaining traction with greenhouse growers.

How to Dip Cuttings

Growers can mix the solution of oils, soaps, or microbial pesticides in large plastic totes. Cuttings are placed in anything that can function as a strainer, submerged into the dipping solution, gently agitated for 5 to 10 seconds, and then removed from the solution. Many growers use mesh carrier trays (a.k.a. “daisy trays”) as a strainer, but almost anything can be used as long as it can withstand the process and allows liquid to drain. Be sure that all surfaces of the cuttings are wet after dipping and be careful to not squeeze or crush cuttings in the process. Many growers let them drip dry and then continue to stick them into the growing media. Check out this video from the Vineland Research and Innovation Centre on how to perform cutting dips.

Learn more in the original eGRO alert here.