Brief Summary of Minutes of Annual Meeting

Collaborators’ observations through the growing season led to the decisions made during our annual meeting. Thierry Besançon’s main concern was design and the need to maintain all areas outside of the OTCs. He had problems with shade from weeds outside the OTCs, and problems with weeds outside the sampling area within the OTCs. Weeds at the margins of the OTCs had to be managed and were challenging to eliminate. He used an application of paraquat to kill plants at margin without affecting the inside of the OTCs.

Maria Gannett scuffle hoed her entire experimental area and moved her sampling area around inside the one-square meter inside the OTCs. She was concerned/unsure about this as scuffle hoeing disturbed the emergence of some weeds and would affect, and likely lower, emergence numbers.

Carolyn Lowry did not move her sampling quadrats within her plots and spiked with a considerable number of seeds in a portion of the plot while leaving some areas un-spiked. This way, she could compare our current dataset and her older dataset. Her team tried not to disturb any area within the plots except in the case of midsummer crusting. They used a rake to lightly break the crust. They had a meter square in the center and spiked different seeds in sub-quadrats within the meter and then did natural emergence outside the spiked area, allowing for both continuity and the non-spiking condition. In Y1, Carolyn used a bit of soybean residue to try to avoid the summer crusting but did not remember it being effective.

Mark VanGessel did not get begin data collection as early as he would have liked, starting in late April or early May. He sprayed Roundup or Liberty to keep weeds down about once per month and sampled the same area each week. He asked what we can do instead of manually counting emergence, and if camera imaging do this for us.

Vipan Kumar brought up that YOLO might be useful. With a good set of pictures, combining different growth stages to young seedlings, we can train a model corresponding from the greenhouse to the field, and that YOLO can do 90% of the job. One of his graduate students is doing greenhouse-grown seedlings, looking at waterhemp and Palmer amaranth. He is also maintaining a common garden with an artificial seedbank, looking at Palmer amaranth and waterhemp from New Jersey, Connecticut, Idaho, Nebraska and Kansas, monitoring weekly emergence without OTCs.

Maria has seedlings so small they’re hard to even see in a photo. Utilizing YOLO would enhance the project and save collaborators time in the long-term.

Thierry stated that data collection and maintenance currently takes three hours/week. If this can be reduced to one hour, he would love it. A concern is that too much time is being spent on data collection and maintenance. He added that we would need a standardized protocol very soon if we use our greenhouse space to grow seedlings this winter for images.

Caroline M. mentioned that our lab doesn’t have enough data loggers to add Vipan’s site at Musgrave in Aurora, NY. Toni will work with Vipan to get more of these.

Toni added that we should develop a protocol for growing seedlings in the greenhouse and share species that each of us are growing. We will talk to Vipan about a protocol for taking pictures. For example, how often to take photos, what type of frame we need, or if we need to build something. Other things to consider are height and frequency of photographs. And then we should update the protocol for the field in terms of crusting and vegetation maintenance.

Thierry asked if we need a pyramid for light intensity.

Maria added that she put soil and temp loggers at two inches and ten inches, and differences in temperatures were significant. Two inches was getting above soil temp consistently and would dip below low temp of ten inches. Insulative properties of soil are more than I suspected. Also, a long discussion of how slight movement from that 2” mark led to significant differences in temperature records. The group suggested allowing dirt to settle before burying the sensor.

Thierry moved their OTCs. Carolyn said she didn’t move theirs. Mark moved theirs. Maria moved theirs slightly and mentioned that theirs are still in the ground and will be removed temporarily so farmers can do some light cultivation to have a cleaner slate. Moving forward, we will leave OTCs in place, sample in the same place each time, take our censors inside over the winter.

One of the overarching goals of this project is to provide effective, affordable methods to simulate increasing temperatures and increasing weather variability in the field, enabling us to better understand the effect of extreme and/or unpredictable meteorological patterns on weed emergence timing. During the 2024-2025 fiscal year, we deployed OTCs in all multistate participant fields, creating a higher temperature microclimate for seedling emergence versus control field conditions. The OTCs modify air and soil temperature while allowing for 95% light transmission. Over several months, we purchased materials, constructed, and shipped OTC kits to collaborators who then built and deployed them in their respective sites. They have so far demonstrated efficacy at creating a modified environment for weed emergence versus field conditions.

Another goal of the project is to collect weed emergence data across the region to refine existing weed emergence models to fit Northeastern data, as well as evaluate how weed emergence timing varies under ambient (control) and increased temperature conditions across multiple sites with different environmental conditions across the region. During this fiscal year, collaborators collected data weekly throughout the growing season with the intent of compiling the resulting data from six states: New Hampshire, New Jersey, New York, Delaware, Pennsylvania, and Massachusetts. Researchers evaluated and continue to monitor how emergence timing varies under ambient (control) and experimental conditions across the Northeast region. In addition, soil temperature, volumetric soil moisture, and soil electrical conductivity were continuously monitored within each plot using in situ probes installed prior to the initiation of the experiment.

Naomi Graseck was hired as a temporary research technician under this grant and has been gaining project management experience leading this project. She also began weed seedling emergence experimental trials in a greenhouse setting in New York, investigating emergence in control and heavily waterlogged soil conditions. Two trials were completed in July and October of 2025 and a third trial is underway.

Maria Gannett presented the project at the University of Massachusetts Research Farm Field Day on August 6, 2025, to a 76-person audience of growers, agricultural service providers, agricultural researchers, and students.

Mark VanGessel presented the experiment as part of the University of Delaware Weed Science field day in June and the University of Delaware Carvel Research Center Field Day in August 2025.

We educated undergraduate students in the Cornell Integrated Pest Management course about meteorological changes anticipated and the effect on weed seedling emergence, and the complexities of modeling and predicting weed emergence. We briefed the weed science community with an update on our project and the changes to the models that our data suggested from the first year of data collection.

No grants, contracts & other resources obtained in relation to this multistate project.

None between October 1, 2024 - September 30, 2025