Tag Archives: powdery mildew

Meet The Team

People: Oregon bound and down; From the land of sun to the land of clouds

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Brent Warneke

Brent inside the west cave of Monkey Face, Smith Rock State Park.

I grew up in Littleton, Colorado amid the suburbs of Denver. Although I was a suburb kid, I grew up gardening from an early age, which sparked my love for plants. Going with what I was interested in, I decided to pursue a degree in something plant related at Colorado State University. I ended up studying horticulture, but took a wide range of classes including brewing technology, microbiology, biochemistry and business. Throughout my time at CSU I worked in a couple different lab groups, one that studied biofuel production and another that was focused on cryopreservation of vegetatively propagated crops. Working in the labs got me interested in science. I took a plant pathology course my senior year and loved how it was an integration of things I had learned in horticulture, microbiology, and other sciences.

Eventually I obtained my BS in Horticultural Science and a minor in Business Administration at CSU. I had such a good time learning about science and working in labs that I decided to pursue graduate school. I looked at a few universities throughout the USA but the prospect of working on specialty crops (fruits and nuts) had me more excited than working on field crops. I ended up landing at Oregon State University in the Botany and Plant Pathology Department. The project I worked on had me investigating fungicide resistance and grape powdery mildew management and I was fortunate to travel to many vineyards throughout the state to take samples and work with growers. Over the course of my Master’s degree I was able to present data from my research at two national plant pathology conferences, one in Tampa, FL and the other in San Antonio, TX, two places I had never been before. These experiences were very useful to hone my science communication skills which I use a lot in my current position.

Brent at Glacier Lake while backpacking in the Eagle Cap wilderness.

After I finished my MS degree I started my current position working on the Intelligent Sprayer project at OSU with Drs. Lloyd Nackley and Jay Pscheidt. The part of the project I fit into investigates using the Intelligent Sprayer to manage grape powdery mildew with various fungicide regimes and investigating sprayer coverage in hazelnut and nursery crops. This has been a great fit for me as I have been able to apply what I learned during my MS and strengthen my research and writing skills. As with all agriculture, we come up with a plan every year and have ideas about how everything will go, but something always surprises us. During the season it’s always a push to collect all the data we need, but when the season is over it is very interesting to sit down, go through the data, and make graphs and connections as to how the treatments we applied fared. Writing up the data into informative reports, and in doing so, making connections to past literature while abstracting it into the future is another part of the process that makes me love what I do.

The 50 gallon air-blast sprayer retrofitted with the Intelligent Spray System connected to a Kubota M5-111 tractor that powers the unit.

I’ve been fortunate to live in two different states that are great for my outdoor oriented lifestyle. I grew up camping, fishing, backpacking, canoeing and skiing in Colorado. I have since gotten into rock climbing, rafting and kayaking, and hunting in Oregon, and especially love spending time on the Oregon coast. If I were to give some advice to someone following a similar career path to me I would tell them to always be open to opportunities and to get out of their comfort zone regularly.

Irrigation

Irrigation: Going LOCOS for On-Site Weather Data

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How we are using low-cost and open-source weather stations for decision support 

Dalyn McCauley

On-farm weather data can provide valuable information to growers including informing irrigation scheduling, tracking plant growth indices, and mitigating damaging events like frost, heat waves or disease. Weather can vary widely across landscapes, even across a single field, and we have found that there is value in having multiple distributed weather stations on-farm to capture variability across small spatial scales. To do this cost effectively, I developed a low-cost open-source weather station (LOCOS) for my M.S. thesis at the University of Idaho that uses low-cost sensors and an Arduino microcontroller for data logging. By distributing multiple LOCOS across a vineyard, we found that there were distinct micro-climates that had varying susceptibility to grape powdery mildew disease. From calculating a Powdery Mildew Risk Index at each station, we saw that some vineyard blocks could benefit from unique fungicide application schedules. You can read more about this project here.

Figure 1: The first iteration of the LOCOS design installed at a vineyard in 2019 (Julieatta, Idaho).
Figure 1: The first iteration of the LOCOS design installed at a vineyard in 2019 (Julieatta, Idaho). 

Since then, the LOCOS have been adapted to study crop water stress. In the summer of 2021, we used LOCOS equipped with infrared thermometers to develop a crop water stress index (CWSI) for hazelnuts. The CWSI is based on leaf temperature and weather data (air temperature, relative humidity, wind speed, and solar radiation). Leaf temperature is a known indicator of plant stress. When a plant is actively transpiring the leaves will be cooler than the surrounding air because of the evaporative cooling effect of transpiration. Whereas a plant that is stressed and not transpiring will have a warmer canopy that is closer to the ambient air temperature. The CWSI varies from 0 to 1, where 1 indicates a stressed, non-transpiring plant, and 0 indicates a well-watered plant transpiring at max potential.  

We used the LOCOS to collect canopy temperature of the hazelnut trees from June to September, 2021. The trees were subject to three different irrigation treatments, over watered, moderate water, and no water (dryland) so we could get a range of canopy temperatures to incorporate into our model. We also collected data on leaf water potential, leaf transpiration and leaf conductance to validate the index against. We found that the CWSI we developed was closely correlated with leaf water potential (r2 = 0.84), leaf conductance (r2 = 0.75) and leaf transpiration (r2 = 0.72). These are exciting results because it shows that the LOCOS could provide continuous data on crop water stress that can be used to inform irrigation decision in near real-time. This summer, we will use the LOCOS in another study to develop a CWSI for red maples. 

Figure 2: LOCOS installed in a hazelnut orchard for CWSI study in 2021 (Aurora, OR).