The purpose of the survey is to provide information to help you make weed management decisions and will include weed species, location, and infestation level monitored monthly. Twenty four points have been marked for sampling. They are distributed from San Luis to Texas Hill and includes the Yuma Mesa. A three to five acre radius will be surveyed around each point and will be reported on an aerial photograph of the county. A separate map will be provided for each species. We know that we can’t find every weed out there across the county and will make an interactive map so that you can include infestations that we have missed. Just send the Arizona Vegetable IPM Team an image of the weed species and the GPS location from your phone and we will add it to the map. Our email is AZVegIPM-Team@email.arizona.edu or contact Marco Pena at marcop@ag.arizona.edu.

It is well known that weeds can be reservoirs for insect pests such as western flower thrips sweetpotato whitefly and for insect-transmitted viruses like Cucurbit Yellow Stunting Disease Virus (CYSDV) or Inpatiens Necrotic Spot Virus (INSV). It is our hope that the survey data aids in identifying concentrations of the weeds that could serve as hosts and are possible sources of infection.

The scale used on this survey for the infestation level on each weed is color coded as follows:

We are reporting a couple of the most abundant weeds in this update. Additional Yuma county weed maps will be uploaded to the site vegetableipmupdate.arizona.edu in the Weed Science Updates  Spatial Distribution of weeds in Yuma County.

The next image contains the location of our 24 sampling points:

Figure 1. Location of areas surveyed


Figure 2. Nettle leaf goosefoot increased in most sampling locations in the Yuma County


Figure 3. Purslane distribution