Managing Pests via Remote Sensing and the Smart Use of Fertilizers

May 12, 2015

Christian Nansen, the UC Davis Department of Entomology and Nematology's new agricultural entomologist will talk about his exciting research on "Remote Sensing and Smart Use of Fertilizers to Manage Pests" at 4 p.m. Thursday, May 14 in Room 2045 of Bainer Hall, UC Davis campus.

It's hosted by the UC Davis Department of Biological and Agricultural Engineering, also known as BAE.

"There are steadily growing concerns about how global and sustainable agricultural production and food security can be maintained in the 21st century and beyond," Nansen says. "It is expected that arthropod pest management in agricultural systems will face profound challenges, as pesticides are being faced out, pests are developing resistance to pesticides, and because growing conditions become less predictable due to climate change and diminishing availability of water for crop irrigation"

"Many arthropod pest outbreaks occur in crops initially being exposed to abiotic stress, such as, drought or unbalanced fertilizer applications. In these cases, an arthropod pest outbreak may be a symptom or consequence of sub-optimal crop management regime."

Nansen's presentation is about "remote sensing of crop stress and how it can be used to minimize risk of pest outbreaks, as crop reflectance data provide insight into some of the mechanisms that are driving pest population dynamics, both temporally and spatially."

At UC Davis, Nansen is focusing on four major themes: host plant stress detection, host selection by arthropods, pesticide performance, and use of reflectance-based imaging in a wide range of research applications.

Born and educated in Denmark, Nansen received his master's degree in biology from the University of Copenhagen in 1995 and his doctorate in zoology from the Royal Veterinary and Agricultural University in Denmark in 2000. He accepted positions in Portugal, Benin, United States, UK and Australia before joining the UC Davis Department of Entomology and Nematology in January as an assistant professor. His international experience also includes being an international exchange student at the University of Lisbon, Portugal and a visiting professor at Northwest A&F University, Yangling, China.

“Agricultural entomology has given me so many opportunities to travel and work internationally, and that has been extremely rewarding,” he said. “I am passionate about food production and how to produce food ‘smartly' – so that it is profitable and also environmentally sustainable. And insects are critically important in manipulated food webs, such as, a crop field, forest, orchard, or horticultural greenhouse. I enjoy studying their ecological roles in these systems and how we can use that information to develop smarter ways to produce food.”

“Even though Denmark is a very small country (5 million people),” Nansen said, “it has been at the forefront of agricultural research and production for many decades."

Nansen previously held faculty positions at Texas A&M, Texas Tech, and most recently at the University of Western Australia. As a university employee, the most common way to “create impact” is by influencing the minds and interests of students, but also of particular stakeholders,” he said.

“While working in Texas, we developed a very effective sampling method for an important insect pest in potato fields, and a 4th generation potato grower (Bruce Barrett) actually changed his management strategy because of our sampling method: he purchased the equipment needed and hired people specifically to conduct insect sampling, as he saw how use of this method could save him thousands of  dollars on insecticide sprays--because he would now have a much better idea about when and where to spray. Recently, in Australia we demonstrated to farmers that sub-optimal maintenance of their stored seed grain led to loss of crop vigor and therefore a loss in crop yields. That is, if the seed grain is poorly managed, then stored grain infestations will likely occur, and these beetles will damage the kernels so they don't germinate. We provided simple guidelines for how the grain storage practices could be improved, so quite a few farmers are now following our guidelines to optimize the vigor of their seed grain.”

“Sometimes, we can go further and actually develop tools or gadgets which end-users may find useful. As an example, we have developed a freely available phone app to optimize pesticide spray applications based on weather and spray settings ( The main goal with this phone app is to guide farmers so that they obtain the best possible spray coverage--to reduce risk of pests developing resistance--and to encourage them NOT to spray pesticides under unfavorable conditions.”