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Rice Overview
Matthew Rhine, research associate with the University of Missouri in the
cropping systems department, gave an overview of the 2015
Missouri Delta Center Rice Research program.
Photo by John LaRose, Jr.
The Best Varieties, Techniques, Management Can Benefit Yields
BETTY VALLE GEGG-NAEGER
MidAmerica Farmer Grower
PORTAGEVILLE, MO.
Matthew Rhine, research associate with the University of Missouri in the cropping systems department, recently gave an overview of the 2015 Missouri Delta Center Rice Research program.
“2015 was our first year of bringing back the MU Rice Variety Trials at the Delta Center,” he began. “We want to give the people of the Bootheel a good opportunity to understand how these varieties are going to work on their soil types. We have several different varieties, both conventional and hybrid.
Rhine showed a slide on gumbo clay soil, where heavy rains in the spring prevented early planting as the ground remained wet. It was mid-June before it could be planted, so this is going to be a very late rice crop. This field was treated basically the same as the others, except it got 150 pounds of nitrogen pre flood.
“RiceTec XP760 was one of the best looking varieties as it shows vigor, emergence, and the highest yield in the study at 224 bushels per acre,” he added. “A lot of them performed quite well, including CL151, Lakast, Mermentau, and Roy J with yields all above 200 bushels. Some of the ones that aren’t holding up so well in this soil are Jazzman II and Wells. We also have a full Clearfield variety trial which runs the full gamut of the Clearfield line.”
Looking at the older lines up into the new ones, one of the best looking lines is the 2014 variety CL172, which had an average yield of 227 bushels per acre. The highest yielding line in the study was CL151 at 238 bushels per acre, followed by the medium grain CL271.
“We also have a seeding rate trial on 172 which runs the gamut anywhere from 20 all the way up to 120 pounds of seed to the acre,” Rhine explained. “This gives you the opportunity to see how these lines react at a reduced seeding rate, often resulting from hail damage in the spring or planter malfunctions. You can see what those stands could look like at those lower seeding rates. Even at the 20 pound seeding rate, we’ve got good tillering, we’ve got good stand that’s been able to compete with the higher seeding rates. Yields were also not significantly different between seeding rates, so a loss in stand for this variety may not be as detrimental as you might think.”
There’s also a furrow rush variety trial at the Delta Center which runs the exact same lines as the flood variety trial. The purpose is to see how well these do in a furrow situation. These are watered according to the MU crop water use app developed by Dr. Gene Stevens with the cropping systems project.
“We put in our soil type, our rooting depth, and that allows us to use the National Weather Service rainfall in order to tell us when to irrigate. So we followed that program,” Rhine said.
“In addition to these varieties, we have three different nitrogen regimes that we’re using. We use 150 pounds pre-flood with urea plus Agrotain, 150 pounds pre-flood as ESN which is a slow release nitrogen; and we also have what we call a spoon feed approach where we put out 50 pounds at pre-flood and then go with four applications of 25 pounds of nitrogen just to feed that crop throughout the season. We want to see which is the best at that point.”
One line that looked among the best was RiceTec CLXL45, and another one that looked really good this year has been Jupiter across these different nitrogen regimes. The best looking nitrogen application has been the ESN so far. With this treatment, that slow release is not broken down so fast and it’s been able to feed that crop really well.
“We also have a DD50 validation trial. The DD50 program from the University of Missouri takes into account the emergence date of your rice and gives you a step-by-step timeline throughout the field throughout the season where you can see exactly how these things line up,” Rhine said. “It shows when first tiller will appear, when you’ll hit mid-season, when you need to apply for armyworms or stink bugs. It gives you all these different parameters that you’re going to need. So this validation trial allows us to decide how these lines are matching up, whether the DD50 is tracking correctly, whether the weather patterns are affecting them differently, and we can calibrate our program based on that.
“We also use this as a nitrogen validation, so we’ll go out with 120 pounds, 150 or 180 on each of these varieties just to see if our nitrogen recommendations are correct,” he reported. “In 2014, the first year of the study, we did this experiment at the Rice Farm in Qulin, Mo. We found our 120 pounds of nitrogen rate was actually our highest yielder. However, the same field was put into the NSTAR program through the University of Arkansas in 2015 and NSTAR recommended only 75 pounds of nitrogen. This particular soil had a lot of residual nitrogen so we found that the extra nitrogen in the 150 and 180 pound rate showed no benefit because of the residual nitrogen. So in this particular instance this year, in 2014, our 120 pound N rate was the best.”
Considering varieties, in 2014 Jupiter was the highest yielder at 179 bushels. Next was CL151 at 165.
“To break that down in head rice yields, Jupiter was also our highest head rice miller, followed by CLX745,” he reported. “So we had some good millers out there, we had some bad ones. Some of our worst were Wells, Roy J and Jazzman. Of course every year is going to be a little bit different.
“In 2015, this study was conducted on a different field, and the more nitrogen we applied the higher our yields climbed. This indicates our residual nitrogen can potentially play a large role in nitrogen use efficiency.”
His group also evaluated the Limas product by BASF. This is a ureas inhibitor very similar to Agrotain but, in addition to the NBPT inhibitor, it has what’s known as a NPPT inhibitor which is proprietary to BASF.
“We’ve done some evaluations with it where we compared it to urea, urea plus Agrotain, and at different recommendations, whether it be 60 percent or 80 percent of your recommended nitrogen rate, to see if we could reduce that nitrogen rate and use it more efficiently with the addition of a ureas inhibitor. We took tubes and put those in the field and we applied urea to wet soil, then we put ammonia traps to check for any volatilization in the field. So we can go in every few days and pull out that trap and see exactly how much nitrogen is lost. We found that the Limas and Agrotain both work really well on wet soil to reduce nitrogen losses.
“We learned you can put out 60 percent of the recommended nitrogen rate with this ureas inhibitor and still get the same effect as if you’re putting out 100 percent of straight urea,” he said. “So we’re not getting that loss there.
“We’re also working with soil and foliar amendments to reduce the rice chalkiness. Rice chalk is the white portions that’s inside the rice grain which are undesirable to a lot of rice consuming countries. There are a lot of factors that increase rice chalkiness. Nitrogen and potassium deficiencies affect plant hormones, which can increase chalkiness. High temperatures over 85 during the night will cause a lot more chalk in rice grain. This is all happening when heading occurs. Water stress also can affect rice chalkiness and genetics too can have an effect on how much chalk the plant makes.”
Rhine reported working with two varieties, CL151 and RiceTec XL753, both of which are known for somewhat higher levels of chalk compared to some other varieties.
“We’re evaluating different soil and foliar amendments to try to reduce rice chalkiness. We’ve done soil potassium applications, application of calcium silicate, and two foliar applications of plant hormones, one of which is gibberellic acid and the other is Kinetin. We’re trying these different amendments to see if we can somehow reduce that rice chalkiness. If there’s something that can be done by a producer, something put on the field, knowing that could produce a higher quality rice at the end, that’s what we’re trying to accomplish with this. This is the first year of that study, we don’t have any data to show yet, but we’re working on it now.”
In summary, the 2015 data shows the RiceTec hybrids XP760 and XL753 were the highest yielding rice. It was followed by CL151, Lakast, Mermentau, and Roy J which followed closely after that.
“We have several new varieties in the pipeline right now that we’re testing. With Marmentau, Lakast, new hybrids, and new Clearfield lines there’s a lot in the pipeline right now we need to evaluate for our region. Hopefully, we’ll continue to generate some good data that we can show to give farmers a heads up on how these varieties are going to work on their farm.”
The DD50 project showed the yields were reduced with high nitrogen rates in 2014,, but that was due to a high amount of residual nitrogen that was in the soil.
“It’s important to think about that going forward if we want nitrogen efficiency,” he said. “We need to know exactly how much is present in these fields so we can plan for that; and as far as rice is concerned, the NSTAR program is really good for that. That’s something to think about in the future.
“As far as the Limas goes, as a ureas inhibitor it works really well compared to Agrotain and things like that. It does a very good job of keeping that nitrogen in the soil, especially when you’re applying on a wet soil. That’s when its most important,” Rhine summed. ∆
BETTY VALLE GEGG-NAEGER: Senior Staff Writer, MidAmerica Farmer Grower
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