How is your corn growing? Aerial surveillance provides answers

UNH researchers show the insights drones can provide by monitoring corn on small farms

University of New Hampshire

With already thin profit margins and increasingly uncertain farm labor and other input costs, precision agriculture technology could improve New England’s small and medium-sized farms’ efficiency, productivity, and resilience. Unfortunately, factors such as up-front costs and validation of the technology’s accuracy in the region remain a barrier to adoption. A research team at UNH led by Benjamin Fraser, visiting assistant professor and director of the Basic and Applied Spatial Analysis Lab, has shown that unmanned aerial vehicles (UAVs), commonly used in precision agriculture, are able to provide effective surveillance of fields planted with corn, including brown-midrib (BMR) corn, an important variety for silage production.

BMR corn provides key silage advantages to dairy farmers, but it is more expensive to grow than many other varieties and is susceptible to disease late in the growing season. Monitoring BMR corn is therefore critical for the New Hampshire dairy industry, but it is also time- and labor-intensive, and field-level inspections often miss early signs of disease. A recent paper presents findings from eight weeks of UAV surveillance of New Hampshire corn fields that assessed its ability to analyze corn characteristics at field- and plot-scale levels. The paper shows that the UAV imagery can differentiate between varieties of corn and estimate crop yields with high accuracy.

“The findings demonstrate that low-cost, consumer available (or ‘off-the-shelf’) UAV sensors with limited spectral range are highly likely to produce accurate results and that the imagery can be used in several ways to inform future corn farming practices,” says Fraser.

Precision monitoring of corn

The applications for precision agriculture tools such as UAVs are varied, from monitoring for weeds and diseases to calculating yields to optimizing harvest timing and site selection, and they are used extensively on large farms in Midwest and Western states. Yet, at this time, usage of precision agriculture methods remains low, about 25%, on small Northeastern farms, largely because of the up-front investment required.

The paper adds to a growing body of research indicating that precision agriculture does provide important advantages in the long term. Overall, it promises to lower costs, particularly for labor, and deliver better outcomes for farmers, bolstering the sustainability of commercial agriculture on small farms in New Hampshire and throughout New England.

The paper, published in Agricultural Research, provides a case study for the use of precision monitoring of corn to collect field- and plot-specific data. The experiment was conducted on UNH agricultural fields planted with brown-midrib (BMR) and non-brown-midrib (non-BMR) varieties. BMR corn has been in use and studied for a century, is easily digested by dairy cows, and can improve milk production. However, BMR corn is susceptible to disease risks and grows and develops quickly, requiring frequent monitoring.

The UAV imagery data was multispectral, meaning that it was acquired across multiple color bands. Using red edge and near infrared wavelengths and a machine learning classification of corn varieties, the researchers were able to distinguish the subtle differences between BMR and non-BMR corn by field with accuracies of up to 98.7%. Narrow-band red edge image data showed high potential for estimating corn yields.

“The team explored ways that UAV imagery could inform field-specific management practices to reduce crop damage and costs,” says Fraser. “It brought many areas of expertise, including Tom Beaudry, a certified crop advisor for dairy producers in New Hampshire, Vermont, and Massachusetts, Carl Majewski, a UNH extension specialist, and Peter Davis and Aaron Palmer, UNH farm managers.”

The team’s research mitigates risks for farmers looking to work with new remote crop monitoring technologies by demonstrating the accuracy and utility of UAV observations. UAVs provide farmers with an affordable, flexible tool for proactively monitoring plant pests and diseases and assessing leaf area and yield. Using the data for consistent, reliable modeling of crop health and yield also provides vital insight for food management and for improving production methods.

“Our team is planning to work with additional private farms in the upcoming field seasons,” concludes Fraser. “We’ll look to quantify direct causes and amounts of loss within corn fields using the lessons learned from this research.”

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The University of New Hampshire inspires innovation and transforms lives in our state, nation and world. More than 15,000 students from 50 states and 87 countries engage with an award-winning faculty in top-ranked programs in business, engineering, law, health and human services, liberal arts and the sciences across more than 200 programs of study. A Carnegie Classification R1 institution, UNH partners with NASA, NOAA, NSF, and NIH, and received over $250 million in competitive external funding in FY24 to further explore and define the frontiers of land, sea and space.

Journal

Agricultural Research

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Use of Unmanned Aerial Vehicles in Precision Agriculture: An Exploration of Remotely Sensed Data and Methods for Monitoring Corn Varieties

Article Publication Date

16-Jan-2026

Breakthroughs for preventing pistachio hull split

UC Davis scientists offer insights into breakage, with potential benefits for fruit crops

University of California - Davis

Prof. Georgia Drakakaki in lab — image:
Professor Georgia Drakakaki studies pistachios in the lab at UC Davis.
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Credit: Trina Kleist/UC Davis

When pistachio hulls split before the nuts are harvested, insects and fungi can get inside, damaging the nut, costing farmers money and contaminating the nuts. About 4% of the overall crop experiences hull split, but some cultivars can split as much as 40% under certain conditions.

Now, for the first time, scientists at the University of California, Davis, are seeking solutions for California’s $2-billion-a-year pistachio industry. New research reveals how the hull is built and how cell walls in certain layers break down, along with the genes and corresponding mechanisms that spark and control those changes.

Pectin, a component of cell walls, makes fruit skin strong in part by keeping cells hitched to each other. In pistachio hulls, the composition of pectin changes as the hull ripens, causing the cells to come unhitched. This leads to cracks and tears in the hull.

In the Journal of Experimental Botany, recent Ph.D. graduate Shuxiao “Susan” Zhang, a student in the lab of Department of Plant Sciences Professor Georgia Drakakaki, identified genes that control how cell walls change as the fruit ripens, leading to the hull breaking down. The research will help breeders select for traits that will make the hulls less vulnerable to tearing and cracking.

“This is the first time anyone has studied the pistachio hull at the anatomical and cellular level while also looking at gene expression and physiological data,” Drakakaki said. “Susan really got into the details of how the hull is built with different layers and how the cells in those layers are of different sizes. The layers respond differently to changes in pectin, and that causes the hull to split in different ways.”

Zhang built on the work of two more scientists in the department and their teams. Grey Monroe, an assistant professor, and Barbara Blanco-Ulate, an associate professor, assembled a reference genome of Pistacia vera ‘Kerman,’ the leading female pistachio cultivar in California. They also defined the stages of the nut’s growth and the characteristics at each stage. Their work was published last year.

A model for fruit split in a variety of crops

Over three years, the team took samples of pistachio hulls from trees in a commercial orchard near Fresno and at the Wolfskill Experimental Orchard, operated by UC Davis near Winters, Calif. They worked with the most common varieties grown in the state, including Kerman, Golden Hills and Lost Hills. They took samples from trees at different points late in the hulls’ development, stretching over several months.

Using special imaging tools and techniques, Zhang and her team measured hull thickness and cell size, and they counted hulls that were intact, tattered, cracked or both. They also measured how well cells in the hull were sticking to each other, and in each sample counted the cells that had come unhitched.

Then the team pulled out RNA from the samples to learn which genes were being expressed at different stages as the hull develops and breaks down. They found that key genes express differently as that process unfolds.

Since all hulls were intact at 91 days after flowering, Zhang and team reasoned that fruit ripening may be linked with hull split. So, the team also examined the genes – including those involved in pectin modification -- that change the cell wall as the fruit ripens. Researchers discovered that cells in the interior layer of the hull expand, while cells in the exterior layer tend to stay the same size. This, in combination with changes in the cell wall, led to different types of hull breakdown.

“This is one of the major novelty factors for our paper,” Zhang said. “Loads of people have looked at pectin in all kinds of fruits, but not many people have observed that, depending on which cell layer you’re in, the pectin, cell size and so on will change differently during ripening.”

The physics of forces operating within the cell layers and humidity also influence degradation of the hull, Zhang found.

Because pistachio hulls are the fruit of the tree, even though we eat the seed, the research has applications for many non-berry fruit crops, Zhang concluded.

The California Pistachio Board funded most of this research, with additional support from the United States Department of Agriculture’s National Institute of Food and Agriculture, the James Monroe McDonald Endowment and the University of California Agricultural and Natural Resources.

Pistachios were harvested at various points during the later stages of fruit ripening, then placed in a solution to preserve them for later examination.

Pistachios, with the greenish hull still on them, are placed on a dissecting microscope to observe the different layers of the hull.

Credit

Trina Kleist/UC Davis

Cells come unhitched from each other in this image of a pistachio hull where it has split. Look at about three o’clock in this photo where it’s violet; the cells look like they're all squished together. To get this image, scientist Shuxiao Zhang took advantage of the cells’ autoflourescence and used a Zeiss LSM980 microscope with 20x objectives.

Credit

Shuxiao Zhang/UC Davis