Rice Farming

When Fred Turner looks into his crystal ball to try to predict a grower’s success at ratooning, the image he sees isn’t crystal clear. But it’s not nearly as foggy as it once was.

The Texas A&M University soils and plant nutrition professor along with research associate, Mike Jund, have developed a test that can predict with about 50 percent accuracy whether the second, or ratoon, crop will produce economic yields.

The test measures total non-structural carbohydrates—TNC, a storehouse of energy for the second crop—in the stems of the main crop. Based on two years of research as well as two additional years working with growers using the test kits on their fields, Turner has found a strong correlation between TNC in stems at main crop harvest and ratoon crop yields.

Seeing is believing
Admittedly a skeptic of the test at first, El Campo, Texas-area producer Layton Raun became a believer the hard way.

Raun was one of the growers who sent about 320 samples from 107 fields to Turner in 2000. “Mine came back and it (the TNC level) was very low, and it recommended that I not stubble,” Raun says. “I did it anyway, and didn’t make a yield.”

In 2001, growers sent 144 samples from 48 fields. Among them was Mark Boenisch, who farms near Garwood and has participated for two years. He says the test gives him more confidence when deciding whether to ratoon.

“If the prices are low and the carbohydrates are low, I’m probably not going to ratoon,” Boenisch says.
Last year, he sampled three fields. The field with the highest carbohydrate level, according to the test, also produced the highest second crop yield.

Before Turner and Jund developed the test, Boenisch says he determined whether to ratoon by checking the stubble after the first cutting to see how quickly it was regrowing.

“If it looked good, you went with it,” Boenisch says. “This test just gives you another idea of where you are. It’s valid.”

And the verdict is ...
Three to five days before harvest, the grower collects a sample from the bottom 10 inches of the plant from three locations in the field. He then sends it by overnight delivery to the Texas A&M Agricultural Research and Extension Center laboratory in Beaumont, where research associate Mike Jund and technician Darrell Hagler use a near infrared method to analyze the TNC content.

Within a few days, Turner and Jund return the results, just in time for the grower to decide whether to produce a second crop. If he decides to go forward, lowering the main crop cutting height to 8 inches from 18 inches will help enhance second crop yields. Co-researcher Dr. Garry McCauley’s data also support the ratoon crop yield increase at lower main crop cutting height.

“It seems like when the ratoon potential is real high, there’s an advantage to lowering the cutting height,” says Turner, who is based in Beaumont. “When the yield potential is low, it doesn’t make any difference whether you cut high or low.

“You can also use this tool to help tell you whether to cut the main crop low or high. Cutting low takes longer to harvest because you are putting all that straw through the combine. Mowing after harvesting is an alternative to cutting low with a combine.”

Higher TNC=higher ratoon potential
With some limits, Turner found that as main crop TNC levels increased from 200 to 1,200 pounds per acre, ratoon crop yields increased from about 1,000 to 3,000 pound per acre.

A farmer with a main crop stem TNC content of 350 or less pounds per acre and no ratoon tillers visible appears to have a ratoon crop yield potential of only 1,200 pounds per acre. Even if the grower invests more than $80 in water, fertilizer, low cutting height and harvest, Turner says data suggest that he probably will lose money because of the low TNC levels.

TNC levels of 1,000 or more pounds per acre typically produced ratoon yields of 3,000 or more pounds per acre.

The exception is if the grower harvests the main crop early—before August—and the disease pressure is low. In 2000, Turner found Jefferson harvested on July 20 with low disease pressure produced ratoon yields of 2,800 to 3,800 pounds, even though the TNC values averaged only 250 pounds per acre.

One explanation could be that even with the low TNC, given enough time a plant encountering low disease pressures can produce a good second crop. The plant also can compensate for low tiller numbers by producing larger panicles when the panicles have enough time under favorable conditions to develop and mature.

Lower cutting height
Turner has also found that by lowering the cutting height of the first crop with good TNC levels, growers can enhance their second crop potential. He theorizes that by reducing the main crop stubble height, growers allow more light to reach the developing tillers.

In 1999 with high ratoon yield potential, the 8-inch cutting height increased second crop yields up to 1,000 pounds per acre under the highest management levels.

In 2000, the lower cutting height increased ratoon yields 500 to 800 pounds per acre.0

Several things you can do to help assure high TNC levels at main crop harvest include:
• Control diseases.
• Make sure nutrients are not limiting plant growth.
• And one thing you can’t control but also affects TNC levels is climate. Good sunlight and cooler night temperatures contribute significantly to high TNC levels at harvest.

Based on his research, Turner says the lower main crop cutting height appears to be the quickest way to improve ratoon yields in Texas. And the benefits of the 8-inch cutting height tended to increase as the ratoon yield potential increased. His research was funded in part by the Texas Rice Research Foundation.

Contact Vicky Boyd at (209) 571-0414 or vlboyd@att.net.

To ratoon or not ratoon New test helps predict whether second crop will be profitable
By Vicky Boyd Editor
When Fred Turner looks into his crystal ball to try to predict a grower’s success at ratooning, the image he sees isn’t crystal clear. But it’s not nearly as foggy as it once was. The Texas A&M University soils and plant nutrition professor along with research associate, Mike Jund, have developed a test that can predict with about 50 percent accuracy whether the second, or ratoon, crop will produce economic yields. The test measures total non-structural carbohydrates—TNC, a storehouse of energy for the second crop—in the stems of the main crop. Based on two years of research as well as two additional years working with growers using the test kits on their fields, Turner has found a strong correlation between TNC in stems at main crop harvest and ratoon crop yields. Seeing is believing Admittedly a skeptic of the test at first, El Campo, Texas-area producer Layton Raun became a believer the hard way. Raun was one of the growers who sent about 320 samples from 107 fields to Turner in 2000. “Mine came back and it (the TNC level) was very low, and it recommended that I not stubble,” Raun says. “I did it anyway, and didn’t make a yield.” In 2001, growers sent 144 samples from 48 fields. Among them was Mark Boenisch, who farms near Garwood and has participated for two years. He says the test gives him more confidence when deciding whether to ratoon. “If the prices are low and the carbohydrates are low, I’m probably not going to ratoon,” Boenisch says. Last year, he sampled three fields. The field with the highest carbohydrate level, according to the test, also produced the highest second crop yield. Before Turner and Jund developed the test, Boenisch says he determined whether to ratoon by checking the stubble after the first cutting to see how quickly it was regrowing. “If it looked good, you went with it,” Boenisch says. “This test just gives you another idea of where you are. It’s valid.” And the verdict is ... Three to five days before harvest, the grower collects a sample from the bottom 10 inches of the plant from three locations in the field. He then sends it by overnight delivery to the Texas A&M Agricultural Research and Extension Center laboratory in Beaumont, where research associate Mike Jund and technician Darrell Hagler use a near infrared method to analyze the TNC content. Within a few days, Turner and Jund return the results, just in time for the grower to decide whether to produce a second crop. If he decides to go forward, lowering the main crop cutting height to 8 inches from 18 inches will help enhance second crop yields. Co-researcher Dr. Garry McCauley’s data also support the ratoon crop yield increase at lower main crop cutting height. “It seems like when the ratoon potential is real high, there’s an advantage to lowering the cutting height,” says Turner, who is based in Beaumont. “When the yield potential is low, it doesn’t make any difference whether you cut high or low. “You can also use this tool to help tell you whether to cut the main crop low or high. Cutting low takes longer to harvest because you are putting all that straw through the combine. Mowing after harvesting is an alternative to cutting low with a combine.” Higher TNC=higher ratoon potential With some limits, Turner found that as main crop TNC levels increased from 200 to 1,200 pounds per acre, ratoon crop yields increased from about 1,000 to 3,000 pound per acre. A farmer with a main crop stem TNC content of 350 or less pounds per acre and no ratoon tillers visible appears to have a ratoon crop yield potential of only 1,200 pounds per acre. Even if the grower invests more than $80 in water, fertilizer, low cutting height and harvest, Turner says data suggest that he probably will lose money because of the low TNC levels. TNC levels of 1,000 or more pounds per acre typically produced ratoon yields of 3,000 or more pounds per acre. The exception is if the grower harvests the main crop early—before August—and the disease pressure is low. In 2000, Turner found Jefferson harvested on July 20 with low disease pressure produced ratoon yields of 2,800 to 3,800 pounds, even though the TNC values averaged only 250 pounds per acre. One explanation could be that even with the low TNC, given enough time a plant encountering low disease pressures can produce a good second crop. The plant also can compensate for low tiller numbers by producing larger panicles when the panicles have enough time under favorable conditions to develop and mature. Lower cutting height Turner has also found that by lowering the cutting height of the first crop with good TNC levels, growers can enhance their second crop potential. He theorizes that by reducing the main crop stubble height, growers allow more light to reach the developing tillers. In 1999 with high ratoon yield potential, the 8-inch cutting height increased second crop yields up to 1,000 pounds per acre under the highest management levels. In 2000, the lower cutting height increased ratoon yields 500 to 800 pounds per acre.0 Several things you can do to help assure high TNC levels at main crop harvest include: • Control diseases. • Make sure nutrients are not limiting plant growth. • And one thing you can’t control but also affects TNC levels is climate. Good sunlight and cooler night temperatures contribute significantly to high TNC levels at harvest. Based on his research, Turner says the lower main crop cutting height appears to be the quickest way to improve ratoon yields in Texas. And the benefits of the 8-inch cutting height tended to increase as the ratoon yield potential increased. His research was funded in part by the Texas Rice Research Foundation. Contact Vicky Boyd at (209) 571-0414 or vlboyd@att.net.
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