UAVs Archives - Nackley Lab

Lloyd Nackley

Nackley Lab field-grown shade trees at the last week of planting. Blocks of 10 trees from left to right Maple, Crabapple, Oak, Serviceberry, Honey Locust, and Kentucky Coffeetree, distinguishable by leaf color and canopy structure. Rows from top to bottom week of planting (March-June) distinguishable by different stage of canopy development.

Oregon growers may have to store trees longer than usual when spring storms in the Midwest and Northeast limit shipping and planting.
We assessed the effects that longer storage has on the health of trees and found that properly stored shade trees were not negatively impacted by longer storage.
Our results indicate a wider window for shipping is possible.

Most of the trees grown in Oregon Nurseries are shipped to the Midwest and Northeast US. In the spring, massive storms in the Midwest and Northeast can put a freeze on trucking and transplanting of bareroot shade trees just as shipping season for Oregon Nurseries heats up. Oregon growers are faced with the question of will increased storage time impacts the quality of the bareroot as the frequency and severity of spring storms increase with Climate Change.

First week of planting at the Nackley Lab field at Oregon State University North Willamette Research and Extension Center (Aurora, Oregon).

Deciduous trees, such as maples, crabapples, oaks, and others are some of the most valuable and most common types of trees grown in Oregon. The Oregon nursery industry takes advantage of plant dormancy periods to dig, store, and ship trees. Large cold storage facilities give nursery growers some flexibility to ship trees when the conditions on the consumer’s end are suitable for planting. For example, trees destined for the Midwest can be held until the region’s colder, longer winter is over.

Trees brought out of cold storage by our grower cooperator, J. Frank Schmidt and Sons.

How long trees can be stored is one of the key physiological questions for optimizing nursery production. Even dormant trees have limits to the length of time they can be kept in cold storage. Dormant trees rely on carbohydrate reserves for respiration and tissue development. The two key risks of storage are desiccation and carbon starvation due to respiration. We must understand the limits to cold storage so that growers can ensure they are shipping healthy, high-quality trees to their customers.

Dr. Rebecca Sheridan using a pressure chamber (model 1505D-EXP, PMS Instruments, Albany OR) to measure stem water potential of trees brought out of storage before being planted.

With support from the Oregon Association of Nurseries research committee and considerable help from the J. Frank Schmidt and Sons crew, we conducted a study, recently published in Frontiers in Plant Science [NL1] , in which we studied the impact of prolonged storage on six genera: Maple, Crabapple, Oak, Serviceberry, Honey Locust, and Kentucky Coffeetree. For each cultivar, we measured stem hydraulic conductance and vulnerability to embolism. Every week for 14 weeks (March–June), we removed trees of each cultivar from cold storage (1–2°C). Each week and for each cultivar, we measured stem water potential and water content. We planted trees each week to track survival and growth. Our results showed that for four cultivars (Maple, Crabapple, Oak, and Serviceberry), the stem water potentials measured in trees removed from storage suggest that the water transport system remains intact during storage. For two cultivars (Honey Locust and Kentucky Coffeetree), the water potential measured on trees out of storage exceeded safe values. However, planted Honey Locust and Kentucky Coffeetree trees from all weeks survived and grew to suggest that these species can repair or rebuild hydraulic function. Overall, the results show that the trees did not experience detrimental water relations or carbon starvation thresholds. Our results suggest that many young deciduous trees are resilient to conditions caused by prolonged dormancy and validate the current storage methods.

Red maples beginning to show true colors towards the end of the growing season.

More info:

Front. Plant Sci. Sheridan and Nackley 2022 https://doi.org/10.3389/fpls.2022.818769

Digger Magazine: http://www.diggermagazine.com/the-cold-shoulder-season/ 2021

I was born in the small farming village of Los Angeles. I lived in the city doing office type jobs until I turned 25 and read a book about the soil microbial community; and everything changed. This book, ’Teaming with Microbes’ by Jeff Lowenfels, is responsible for my complete career change. It was written so the first half taught the science behind soil and plant interactions while the second half explained how to use this knowledge in a home garden.

At the time I lived in a 3rd story apartment building with a balcony that, in no time, was overflowing with vegetable plants and bubbling buckets of compost tea. The success of the garden was directly related to my new-found understanding of soil. I moved out of California and went back to school at the age of 30 to follow my new found passion. My first class was Soil 101 at the local community college in Clackamas. Learning about the “why” behind life science fascinated me. I quickly finished a two year degree and transferred to Oregon State University.

Majoring in Crop and Soil Science while working in a soil microbiology lab took up all my time; when I wasn’t on my daily commute of 160 miles or staying up all night with two young daughters who didn’t like to sleep. After completing my bachelor’s degree, I joined the Dragila Lab and began working on my master’s degree in Soil Physics. I loved doing research and worked on a large, multi-department thesis project studying the effectiveness of soil solarization in Pacific Northwest nurseries. Soil Solarization required a tilled row of soil to be tightly wrapped in clear plastic sheeting. The clear plastic would use the greenhouse effect to super heat the soil, killing soil pathogens and weed seeds. During the three year project, I installed over 600 soil sensors for monitoring soil moisture and temperature movement under the plastic treatments, while other departments assessed the mortality to the weeds and pathogens. At the end of my thesis work, I had produced a model for predicting weed seed mortality from solarization.

Upon completion of grad school, I went into extension where my passion for science communication was used in combination with my knowledge of technology in horticulture. I have been working for OSU at the North Willamette Research and Extension Center since 2019. In the Nackley Lab as a Faculty Research Assistant I set up experiments that explore greenhouse and nursery production. Current projects include: flying UAV’s with near red spectrum cameras to look for plant stress from the sky, VWC sensor base irrigation of shade trees and lysimeter controlled irrigation for indoor hemp production. I am also part of OSU’s Intelligent Spray Project where an air-blast sprayer that has been retrofitted with a LiDAR system is evaluated for efficacy and pesticide savings in the nursery industry. My favorite part of doing research is setting up a new experiment in a way that will hopefully show differences in plant growth based on different treatments. The challenge of working with Mother Nature while manipulating the factors of plant growth fascinates me, especially when there are visual growth differences attributable to the experiment’s set up. These days I can be found either fiddling with technology, setting up overly complicated irrigation systems or at a podium giving talks about what information has been gained from the results of my trials. Where ever you do find me, you can be sure I am on a passionate course for understanding the whys behind growing plants.

Nackley Lab

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