Location: Application Technology Research
Project Number: 5082-21000-001-19-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2019
End Date: Jul 31, 2021
The goal of this project will be to address weed control in nursery containers to complement new subdressing and bark application technologies.
Research will focus on several areas that need to be addressed in order for growers to remain profitable. We will document the persistence of herbicide active ingredients under different production scenarios. With this knowledge, we can make better herbicide recommendations and optimize herbicide use to create longer reapplication intervals to reduce herbicide costs. Additional research is needed to evaluate the effect of subdressing on weed establishment and growth as well as to determine crop response to different placement methods. We will evaluate new substrate stratification methods to create two discrete substrate zones in a container, using a standard potting mix on the bottom half of the container, and a very coarse potting mix on the top half of the container. The manner in which bark suppliers are separating their bark inventories into differing particle sizes, and the manner in which nurseries fill their pots half at a time (to facilitate the subdressing) will be evaluated for their impact on weed establishment and crop growth. Other areas of research include developing methods of controlling weeds in pot drain holes. We will evaluate cultural practices that affect weed establishment in drain holes and chemical control options. We will also work with manufacturers to design drain holes that limit weed growth. We will determine how long a container must be maintained weed-free to prevent competition from weeds and reduction in growth and evaluate the necessity for herbicide applications every 60 to 90 days during the production cycle. Research will be conducted on the persistence of herbicides during heavy rainfall to identify future research activities to help nurseries cope with severe weather.