Biosystems Engineering Grad Helps Bayer Look for New Corn Pollination Windows

Friday, August 14, 2020
UArizona Biosystems Engineering graduate Caroline Schulte hand-pollinates corn at the Bayer Marana Greenhouse as part of her summer internship.

In a traditional outdoor farm system, corn can be pollinated once a day, typically in the morning. But Bayer’s Marana Greenhouse is not a traditional system, and their team is looking to change what ‘typical’ pollination looks like.

Caroline Schulte, a recent graduate of from University of Arizona Department of Biosystems of Engineering and a summer intern at the Marana site, is conducting research to determine the optimal times for pollinating corn in the controlled environment. The major reasons for the limited time frame for pollination viability, according to Schulte, is due to uncontrolled outdoor environmental conditions – especially humidity.

However, the unique capabilities of the Marana Greenhouse may allow for a larger window for the pollination process, increasing the frequency of pollination per day as well as increasing the quality of the pollen.

“With increased pollination we would see an expedited research and development process, getting more sustainable corn out into the world more efficiently,” Schulte says. “It’s a small part in the big picture, but every bit of it helps overall.”

The Marana site focuses on breeding seeds that will eventually grow more sustainable corn, including plants that require less water and less pesticides.

Each stalk of corn onsite is hand-pollinated by placing a bag over the tassel, which is the male part of the plant. The next day the bag is removed with the pollen inside and moved to the silk, which is the female part of the plant. This controlled system avoids any cross-pollination that would disrupt research.

Instead of moving the bag from the tassel to the silk, Schulte removes the bag from the tassel and examines the pollen under a microscope. She then rates the pollen on a scale of “Good,” “Intermediate,” and “Bad” based on the size, shape, and color of the pollen. Large, consistently round, and bright yellow pollen is rated the highest viability.

The decision to research pollen viability came from a few greenhouse team members, including Megan Dickens, the Protected Culture Production Operations Lead. She says they combined perspectives from the Production Team, Agronomy Team, and Systems Performance and Optimization Team to determine the next step in improving all of their work.

“As we move more into production, we decided we want to have a good feel for pollen quality,” Dickens says. “If we don’t have good pollen quality everything else that we’re doing doesn’t really matter.”

When the Marana team initiated the research topic, they purposely left it open-ended so Shulte could take it in her own direction using her past experiences to guide her. Shulte has spent the past few years doing research in various greenhouses at the University of Arizona.   

“The data Caroline is putting together is going to paint a clearer picture than we ever had before on how pollen preforms in our greenhouse,” Dickens says. “This is almost like steppingstone one, but such an important one as we continue leveraging her tools and methods to learn as we expand into new greenhouses and continue to play with our environmental control.”

This research project also ties perfectly into Schulte’s larger life goals. After starting at the University of Arizona studying biomedical engineering, she ended up changing paths and graduating from UA in May with a degree in biosystems engineering.

“I was originally in biomedical engineering because I went to college to help people, and I thought I could only do that if I went in to medicine,” Schulte says, though she found out that was not the case.

“The way I think about it is biomedical engineers try to keep people alive for longer, while biosystems engineers focus on our basic human needs – getting water to everyone, getting food to everyone,” Schulte says. “As our populations keep increasing, it doesn’t matter if we keep people alive longer if we don’t have enough food to sustain everyone.”

She plans on returning to UA this year to complete her master’s degree also in biosystems engineering, maintaining the idea that in order to help keep the growing population fed worldwide, sustainability is key.