In July 2002, a drought settled over Missouri that lasted 99 weeks and finally ended in May 2004.
Eight years later during the week of Aug. 21, Missouri suffered the most intense drought in its history. The dry spell affected 35.72% of land in the state, according to the U.S. Drought Monitor.
Then again in 2018, an extreme drought took hold of Missouri in the spring. Less than half an inch of rain fell on Boone County during the month of April, hay was scarce and farmers had to cull their herds.
Prolonged droughts like these can be devastating to crops, livestock, the level of water in streams and ponds and the overall health of the state economy.
Now, researchers in the Division of Plant Sciences at MU are using drought simulators known as rainout shelters to address the potential decline in plant production and growth.
“Drought is a very important factor in plant growth and productivity,” said Felix Fritschi, a professor of bioenergy crop physiology and genetics at MU. “It’s one of the most important abiotic stresses that occurs here in Missouri.”
Fritschi is one of the lead researchers on the project, which uses the rainout shelters to control water availability on small fields. They are specifically intended as research tools for soybeans and corn, the top commodities in Missouri agriculture.
The shelter is essentially a 50-by-100 foot greenhouse on wheels with clear polycarbonate covers, bifold doors and a gauge that senses rainfall.
When rainfall is indicated, the gauge triggers the simulator to move and cover a specific area within the crop. The shelter then creates a man-made drought to see how plants react to stress in such an environment.
The researchers analyze what happens to the plants under stress, as well as what makes them more tolerant to drought conditions. That, in turn, will help them to identify solutions, such as developing corn and soybean hybrids able to tolerate drought conditions.
Four rainout shelters are set up at MU research centers within the state. Two have been placed at the Bradford Research Center in Columbia, a third at the Fisher Delta Research Center in Portageville and the fourth at the Horticulture Agroforestry Research Center in New Franklin.
The simulators were built in 2009 after Fritschi received a $1.56 million grant from the Missouri Life Sciences Research Board, according to the CAFNR website.
“They are mechanistic studies in essence,” he said. “That means we are trying to learn about the processes, dissect the processes and have a better understanding so we can come up with strategies that hopefully will help breeders improve the next round of hybrids to be more tolerant to droughts.”
Droughts in the western U.S. are more predictable, he said, but they don’t mimic the conditions found in Missouri.
“Having these rainout shelters here is directly applicable to our soil types, biotic conditions and climatic conditions in general for farmers working in the field,” Fritschi said.
“We are not worried about plant survival,” he added. “We are worried about productivity.”
Fritschi said rainout shelter research has focused specifically on soybeans and corn in the field, since they are two of the most significant crops in Missouri. More than 3 million acres of corn are grown in the state, for example, and they can be severely impacted during periods of drought.
During an average summer, seasonal precipitation keeps the soil wet enough for the corn to grow and thrive. In a drought, a condition known as “rootless corn syndrome” may occur where the plants do not develop a nodal or “anchor” root system.
Sometimes known as “floppy corn syndrome,” the condition threatens the viability of the plants, often causing them to collapse in a wind and break.
“These plants may appear normal but begin to lodge when plants are about 15 inches tall because they are weakly anchored,” said William Wiebold, director of the MU Variety Testing Program and the Missouri Soybean Center.
That eventually leads to harvest losses, according to the Purdue University Cooperative Extension Service.
Fritschi hopes to continue using the rainout shelters to better understand what the plant undergoes during the simulations from the plant seedling to root and then growth production.
“Other projects on corn include the growth physiology of root tips,” Fritschi said, “so that includes how the root tips respond to process stress and (if) the roots continue to grow.”
Although there is hope farmers will be able to plant drought-tolerant crops one day, Fritschi said he doesn’t know quite when that will happen.
“People around the world are also studying this topic,” he said. “And it will take a lot of people to figure out how to make plants grow with less water.”