I’m Bryan Brown, the new Integrated Weed Management Specialist at NYS IPM. I’m thrilled to have this opportunity to work with growers and promote IPM solutions for weed management. I came here from the University of Maine, where I compared the economic and ecological effects of several weed management strategies and tested a new cultivation technology that uses several tools, sometimes in tandem, to target the in-row zone.
Integrated weed management
No single weed control tactic is completely effective. And relying on one single tactic is how weeds develop resistance. So what we need to do is integrate more tactics. Attack weeds in as many ways as possible. For conventional growers, a basic step is to use a range of herbicides with different modes of action. Other direct controls include cultivation, flaming, mowing, and biocontrol.
Less direct tactics can also make a huge difference in weed control effectiveness. For example, crop rotation allows for use of different herbicides, fertility, and tillage dates — all of which can be adjusted to combat certain weed species. Likewise, crop cultivar and plant spacing can be altered to maximize competitiveness with weeds, and cover-crop residues can lessen weed emergence. Growers can be even more successful with these practices if they are used to target the biology and life cycle of their most problematic weeds.
When many growers think about weeds, they think of big nasty plants. But I like to encourage growers to think about weed seeds. The number of weed seeds in the soil is very important to the success of weed control tactics. Even if you kill 99% of the weeds in your crop, if you start with 1,000 germinating weed seeds per square foot (yes, that’s common), ten of those weeds will survive and compete with your crop. So depleting the number of weed seeds in the soil is key to effective management. As is often the case in IPM, an ounce of prevention is worth a pound of cure.
How do you reduce the number of weed seeds in the soil? Control weeds before they produce seed, mow crop boarders to prevent seeds from blowing in, and use seed-free fertilizers. You can also create a stale seedbed by encouraging weed seeds to germinate, then killing them before planting. With these techniques, some farmers have sharply reduced the number of weed seeds in their soil, improving their in-season weed control.
I’m especially interested in finding weed management solutions that have multiple benefits. For example, cultivation kills weeds but can also be used to increase nitrogen mineralization, improve water infiltration, and control soil-dwelling pests like cutworms. Cover-crop residue can suppress weeds but it can also increase soil organic matter, interfere with navigation of some insect pests, and reduce splashing of soil-borne pathogens. So perhaps weed management can be integrated with management of soils, pathogens, and insect pests?
If you’re interested, please contact me at 315-787-2432 or firstname.lastname@example.org.