Episode 116: Weeds and IPM

Weed management is the bane of existence for many gardeners and one of the most critical aspects of farming and land management. Finding safe, effective, and culturally appropriate weed management solutions is a challenge but can be addressed by betting understand the life cycle of the specific weed that is causing a problem.

Dr. Bryan Brown is a Senior Extension Associate, NYS Integrated Pest Management and Adjunct Assistant Professor, School of Integrative Plant Science Horticulture Section at Cornell University’s College of Agriculture and Life Sciences. He joins Nature Calls: Conversations from the Hudson Valley to discuss Weeds and IPM (Integrated Pest Management). Bryan’s focus is on improving the management of weeds while minimizing the environmental, economic and human health risks.

Integrated Pest Management (IPM) is a decision-making process that uses science-based information on the life cycles of pests (including weeds) and their interaction with the environment to manage damage by the most economical means, and with the least possible hazard, to people, property, and the environment. In the case of weed management, it may involve hand pulling, tilling the soil, covering the soil with cardboard, solarization, other mechanical removal means, or chemical controls. IPM weed management steps typically include:

1. Identifying the plant(s)that are the source of the problem.
2. Understanding the biology and economics of the weed, where it is found, and any potential ‘Achilles heel’.
3. Monitoring plants including any natural controls (insects, competing plants, etc.).
4. Establishing any injury thresholds to understand the potential damage from infestations, its natural enemies, the sensitivity of the site, and the weather. Actions should be taken only when the potential damage is justified.
5. Selecting an appropriate control strategy.

• Cultural practices include modification of habitat or operating procedures to minimize damage and enhance natural control. Choosing plant varieties that are resistant to pests, or adjusting planting time, fertilization, tillage, and harvest operations to have the most beneficial effect on the weed management situation.
• Biological controls including predators, parasites, and diseases.
• Chemical control involves selecting an herbicide with the lowest toxicity to humans and non-target organisms and using it in such a way as to prevent or minimize undesirable environmental effects. After carefully reading the label, the lowest effective dosage of chemical is applied at the appropriate time of year.

Evaluating the weed management program and improving it when possible.

In this episode, you’ll learn about the importance of understanding the weed’s life cycle, whether it’s an annual, biennial, or perennial to assess potential control techniques. For annuals, it’s critical to stop the plant from going to seed. For perennials, interrupting the plants' ability to send energy to its spreading roots is key to success. So using cover crops or mowing at the right time of year and the right height can make a difference. Hoes can help with mechanical removal. There are many types available, but the best one is a personal preference.

Research efforts are underway to determine potential biological controls for some problematic weeds like Japanese knotweed. As Bryan says, there are lots of new developments coming to help with weed management in the future.

Hosts: Tim Kennelty and Jean Thomas

Guest: Dr. Bryan Brown

Photo by: Cornell University

Production Support: Linda Aydlett, Deven Connelly, Teresa Golden, Xandra Powers, Annie Scibienski

Resources

• Weed Life Cycles (psu.edu)
• Weeds of the Northeast by Joseph C. Neal, Richard H. Uva, Joseph M. DiTomaso and Antonio DiTommaso | Paperback | Cornell University Press
• Weed Science | CALS (cornell.edu)

Last updated April 5, 2024