Rice breeders rally after weather, market shifts to design better varieties
Beaumont, Texas, USA
February 3, 2016
When the weather or the market shifts in a year, farmers feel the impact immediately – be it good or bad.
But for the scientists who spend a lifetime figuring out ways to create new varieties to feed more people, weird weather and market movements are welcomed for the lessons they teach.
That was the message recently when about 40 rice breeders from four states converged at the Texas A&M AgriLife Research and Extension Center in Beaumont to compare notes about the most recent growing season and what promising varieties might be emerging from their programs.
“Every time a new variety of rice gets released by a breeder, it has gone through a gauntlet basically of having been grown multiple years in multiple locations to see how well it performs,” said Dr. Ted Wilson, center director at Beaumont. “It’s a process of weeding out those varieties that are likely going to have problems somewhere down the road because of grain quality, because the yield is just not quite there, or because disease resistance is not high enough.”
Dr. Ted Wilson, center director, Texas A&M AgriLife Research and Extension Center- Beaumont. (Texas A&M AgriLife Research photo by Kathleen Phillips)
Testing in field conditions for a number of years is important, he said, because weather variations can throw a curve in an otherwise strong contender.
“In 2015 in Texas and Louisiana, for example, it was extremely wet early on, so planting was later,” Wilson noted. “And, since farmers in those two states produce two crops a year — the main crop and the ratoon crop — the later you plant, the more likely the crop will be flowering in higher heat in late-June, July, August, which can take a toll on yield.”
The wetter than normal 2015 season also led to disease pressures, he said, and yet while the main crop had lower yield, the ratoon crop produced record yields.
“Think of the rice plant having pockets,” Wilson explained. “These pockets are where sugar is stuffed. The sugars turn into starches and make the grain. If you have fewer grains because the heat hurt the plant, the plant has left over energy in the form of starches and sugars, and it stuffs them into the stems. That high level of what we call nonstructural carbohydrates comes in handy for the second crop, because when the straw — the lower 8 inches of the plant — has high levels of starches, it can just go like gangbusters and make a second crop that is higher yielding than normal.
“We don’t want to see a bad first crop like this year, but when we get a high yielding ratoon crop, it’s a savior,” he said.
It’s that sort of unusual situation breeders consider when they gather each year to report on how well test varieties performed.
“By exchanging information, rice breeders learn similarities and dissimilarities and that helps explain what and why things went wrong or what and why things went quite well.” Wilson said.
Wilson told the rice scientists at the meeting that the trend among Texas growers is moving more toward planting hybrid varieties, which have only been available for little more than 10 years. Previously, the only type of rice seed was what is called “inbred.”
But Wilson said in 2012, hybrid varieties for the first time accounted for more than 50 percent of the acreage. But the hybrid plantings dropped back in 2015, most likely due to rice market prices being suppressed and the higher cost for hybrid seed.
Hybrids typically yield as much as 18 percent more than inbreds, but there are pluses and minuses for both types, he said.
Rice at Texas A&M AgriLife Research Center near Beaumont in July. (Texas A&M AgriLife Research photo by Kathleen Phillips).
“Inbred seed is cheaper and the grain quality historically is much higher than hybrids,” Wilson noted. “But the use of nitrogen is slightly more for inbreds, so that’s bad, because it is a cost. Disease resistance tends to be slightly higher for hybrids, which is a plus.”
Wilson also told the breeders that a recent study at the Beaumont center showed that for several historic rice varieties when examined under different fertilizer and management regimes, genetics explained 45 percent of the increase in yield over time and management explained 55 percent of the increase.
“If all our rice growers were to get 80 percent of the maximum yield for the main crop and if they planted on time and were able to get a ratoon crop to get 80 percent of the maximum ratoon crop yield, the overall yield in Texas alone with no further improvements in varieties would increase by 63 percent to 13,000 pounds per acre,” Wilson said. “The point is that genetics is important but management is a big part of the ballgame, too.
“The fact of the matter is that maybe in some situations the genetics is more important and in some situations management is more important,” he added. “What is really important is that both of them are needed to make rice production profitable anywhere in the world.”
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