Farm Progress

Arizona researchers tackle improved heat and drought tolerance in Upland and Pima cotton cultivars with possibly higher yields.Three-year-old project called “high throughput phenotyping of cotton” is led by USDA-ARS research geneticist Mike Gore, with technology input from University of Arizona precision agriculture specialist Pedro Andrade.Project has potential benefits across the Cotton Belt and in many different crops worldwide, including wheat, rice, and soybeans.

September 24, 2012

6 Min Read

An Arizona cotton research project which combines plant breeding and precision agriculture technologies could blow the door off the hinge by improving overall crop tolerance to drought and high heat without yield loss.

The three-year-old project called “high throughput phenotyping of cotton” is led by research geneticist Mike Gore based at the USDA-ARS’ U.S. Arid-Land Agricultural Research Center (ALARC) in Maricopa, Ariz.

One of Gore’s collaborators on the technology side is precision agriculture specialist Pedro Andrade of the University of Arizona (UA) Maricopa Agricultural Center (MAC), also located in Maricopa.

Gore conducts cotton breeding and genetics research at the ALARC laboratory while in-field cultivar tests are measured with precision agriculture measurement tools by Andrade a mile down the road.

Gore’s goal is to develop cotton cultivars which cool during the growing season. A plant reduces its canopy temperature via transpiration (sweating), which helps the plant better tolerate high heat and drought.

Cotton cultivars in general have been developed to better endure high heat and drought. The major drawback is typically reduced fiber yield which reduces the grower’s profit potential.

Gore is breeding for the whole shebang — effective heat and drought tolerance with either no reduction in yield or possibly a yield increase. The success of the project could have far-reaching benefits across a plethora of crops grown around the world.

Cotton phenotypes (traits) are similar to the traits of hair and eye color in humans.

“There is a genetic reason for hair and eye color and a person’s height. While these are easily distinguishable in humans, a plant trait including canopy temperature is more difficult to see,” says Gore, who received his doctorate in plant breeding from Cornell University.

The research project this year includes 135 cultivars of Upland and Pima cottons grown to maturity in a MAC field under extreme desert heat and low water. Next year, Gore will plant and test about 1,000 cultivars.

Gore says the trick is to identify the genes in the cotton genome responsible for plant cooling and use the findings to breed cotton with a level of plant cooling which minimizes water loss while maintaining yield.

“This is a tall order but I believe we can achieve it.”

Gore believes multiple traits must be studied to generate heat and drought tolerant cotton. While the entire Upland and Pima cotton genome have not been sequenced or identified, Gore believes cotton has 60,000 to 80,000 separate genes which offer a lot of information. Each one must be identified and studied.

Others collaborating with Gore in the breeding are the ARS’ Jeff White, Andy French, and Kelly Thorp, also based at ALARC.

Precision ag tools

Andrade says precision agriculture tools will play a major role in Gore’s cultivar challenge by gathering precise information as the cultivars grow in the field.

Andrade earned his doctorate from the University of California, Davis in agricultural and biosystems engineering. He joined forces with UA research specialist John Heun to outfit a re-designed, high-clearance sprayer with high-tech sensors, GPS, and electronic acquisition instruments.

The unit travels down cultivar rows precisely measuring plant components and interactions before the equipment platform touches the plants.

“Mechanically-powered equipment moves these platforms faster through the plot and covers ground faster than a crew of workers,” Andrade explains.

The precision agriculture tools are mounted on the front boom. The equipment includes infrared thermometer sensors which measure canopy temperature, and sonar transducers which scan canopy height.

Active spectral sensors record the amount of light reflected by the plant. A rapid-moving Lidar laser captures the plant’s geometry. Three data loggers tally the data into a single mathematical algorithm.

This information is geo-referenced with serial output from a Hemisphere GPS-RTK Outback A320 ultra-precise positioning system. Additional navigation instrumentation from the Trimble CFX-750 provides steering assistance to the rig moving down the plant row and precisely turns the rig around to the next row of cultivars. The unit travels at one mile per hour.

The rig and electronic tools travel through the test plot four times a day – 7 a.m. and 10 a.m.; and 1 p.m. and 3 p.m. The afternoon readings dramatically vary from the morning readings due to extreme heat.

The rig travels through the plot weekly during the cotton-growing season to gather critical data over the plant development cycle.

Andrade says, “This provides a real-time picture of how different cotton cultivars handle heat and drought season long.”

The Gore-Andrade team reviews the gleaned information to determine which cultivars better tolerate heat and drought. Successful cultivars are bred together to create the next generation of cultivars for tests.

Part of Gore’s effort to generate higher yield despite environmental challenges is generating data on the plant’s geometric stature or shape. Gore gathers comprehensive, phenotypic data designed to increase lint yields. Perhaps the plant geometry can be reinvented to spur higher yield.

Gore’s rationale is based on his previous job experience in corn breeding. About 30 years ago, corn seed was planted much farther apart than today.

Research on the corn plant’s physical structure suggested that a higher leaf angle on the stalk, including the flag leaf, increased the plant’s capture potential of sunlight. This revelation ultimately changed the industry. Corn plants today are grown closer and generate higher yields as a result.

The same, Gore says, could be true in cotton.

Benefits across Cotton Belt

The information gained in the Arizona cotton study is geared specifically for cotton production in Arizona’s dry, arid climate. Yet the lessons learned could benefit producers across the Cotton Belt.

Gore says, “Each growing region has different environmental conditions which directly impact cotton plant yield. The environment in Arizona is unique and valuable for testing the heat and drought tolerance of cotton cultivars developed for the Cotton Belt.”

ARS-based research results are open to the public and companies at no charge. The information can be cloned or re-purposed for specific uses. Gore expects a complete software package from the Arizona project could be available in about five years. The Arizona research project is ongoing and will evolve over time.

The project is funded by Cotton Incorporated, USDA-ARS, and UA.

Cotton is not the only crop which could benefit from the project. ARS research geneticist Jesse Poland in Manhattan, Kan., is applying the Arizona canopy spectral and temperature components in wheat and soybean breeding trials.

The Arizona project has received global interest. A scientist from the International Rice Research Institute in Los Baños, Philippines, travelled to Arizona to discuss the possible application of Gore and Andrade’s research for developing drought-resistant rice.

A major side benefit of the Arizona project is scientists and engineers working together to achieve a common goal, Andrade explains. This allows various disciplines to work together which is happening more and more in research circles across the U.S.

“It is extremely powerful when you join the best technology across disciplines — in this case genetics, engineering, and precision agriculture. It’s a win-win opportunity,” Andrade believes.

In summary, Gore and Andrade have strong passions to enhance crops to improve profitability for producers. In the larger perspective, Gore says it’s about preparing agriculture to meet the needs of a burgeoning world population.

“I see the huge challenge facing agriculture is how to feed, clothe, and fuel a projected world population of 9 billion people by the year 2050,” the plant breeder says.

“My goal is to develop germplasm across a wide range of crops to meet the world’s future needs.”

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