There has been considerable talk about limited availability of herbicides for the summer of 2021. Recent conversations with company representatives and other weed scientists about the possibility of disruptions in herbicide supplies resulted in a range of responses. Many cited COVID-related issues related to shipping at various stages in the production/retail process. Most indicated that the initial deliveries to retailers this winter were complete, but product availability is likely to be limited as we move later into the growing season.Source : ksu.edu
What can you do in response to this situation?
Purchase products early. I am not advocating stock-piling products or a panicked response in any way. I am strongly encouraging responsible attempts to acquire the product you will need this summer at the earliest possible date. It is likely that that product you need is available somewhere, but will take considerably longer than usual to deliver. If you are able to secure product ahead of time, be sure you have adequate storage space. One consideration that could simplify storage concerns would be to opt for dry formulations rather that liquids.
Be proactive with herbicide applications. Using effective residual herbicides and making properly-timed applications to emerged weeds will reduce the chances that you will need to make unplanned applications later in the season.
Use diverse weed management strategies. Using multiple effective herbicides with each application is recommended to manage herbicide resistance, but could prevent a weed control failure if one of the effective products is unavailable. Also, remember the value of good agronomic practices for a crop that can canopy early and effectively compete with weeds.
Have a backup plan. Know what you will do if your preferred product is not available. Is there an alternative with the same or similar active ingredient? The K-State Chemical Weed Control Guide can be a valuable reference to identify alternative products.