• By Vicky Boyd,
For the first time in its history, RiceTec plans to launch a variety — RTv7231 MA — for the 2022 season. It will likely be joined by the hybrid, RT7331 MA, both of which belong to the Max-Ace rice production system and have tolerance to over-the-top applications of the Highcard herbicide from Adama.
The Alvin, Texas-based rice developer showed off its Max-Ace porfolio as well as recently launched hybrids and pending releases at a recent field day near Iota, Louisiana.
RTv7231 MA was in small-plot research in 2020. It stands about 42 inches tall, and RiceTec recommends applying 130 pounds of nitrogen per acre. That compares to the 150 pounds N per acre recommended for hybrids.
“With the variety, we don’t want to over-fertilize,” said Nicky Miller, a RiceTec sales representative for South Louisiana. “We want to put on 130 pounds max.”
And unlike the hybrids, RTv7231 MA will likely require a fungicide treatment. It also has a smooth leaf.
RiceTec district sales manager Craig Hamm said they planted the variety at about 46 pounds per acre, but the seed had the Squad encrustment on it, which increases seed weight by about 15%. Without the treatment, they would have planted at about 40 pounds per acre.
Optimum moisture at harvest should be 18% to 20% to ensure grain quality.
RT7331 MA has the same parent as the high-yielding XP753, and “we don’t see much of a yield difference between the two,” Miller said. The Max-Ace hybrid stands about 46 inches tall.
RiceTec is awaiting Canadian approval of the Max-Ace herbicide tolerance trait. As a result, harvests from this season’s demonstration fields will be identity preserved and channeled accordingly.
“We’re hopeful we’ll be able to offer this for the 2022 crop,” Hamm said. “We still have the hurdle of Canadian registration, but we’re very hopeful that will happen by the end of the summer. But there’s no guarantee at this point.”
If that comes to fruition, Miller told attendees that RiceTec should have sufficient supplies of RTv7231 MA for next season.
Both of the Max-Ace offerings are paired with Highcard herbicide from Adama Crop Protection. An ACCase, Highcard contains the active ingredient, quizalofop, plus a proprietary safener.
Because Highcard only targets grassy weeds, such as weedy rice, growers will need to add broad leaf control, said Adama tech service representative Jason Meier. Although Highcard is compatible with many other herbicides in a tankmix, he warned against tankmixing it with propanil.
The Adama herbicide is labeled for no more than two applications of 15.5 ounces each per season, and it can only be used on Max-Ace rice. The first application should be made to one- to two-leaf rice, followed at least 10 days later at the four- to five-leaf rice stage.
If possible, applications should be made on warm, sunny days to avoid crop response.
“If it’s cool or cloudy, it increases the risk of symptoms,” Meier said.
Other new or pending offerings
Also showcased were two FullPage releases, RT7523 FP and RT7421 FP. Until this year, RT7421 FP had not been planted on a large scale, Hamm said. With a maturity between RT7321 FP and RT7521 FP, it has shown a 10% to 15% yield advantage over the discontinued conventional hybrid, XL745.
RT7421 FP also has very low chalk and a head rice average similar to other hybrids. For growers who follow with crawfish, he recommended rolling or flail mowing it before flooding.
RT7523 FP is similar in agronomic characteristics to the conventional hybrid, RT7501.
FullPage hybrids have been bred to tolerate over-the-top applications of imidazolinone herbicides. Only Preface and Postscript herbicides from Adama can be used on FullPage rice.
In addition, RiceTec has a new conventional hybrid, RT7401, with a maturity between RT7301 and RT7501.
In the works are XP777, a smooth-leaf conventional hybrid, and XP778, a conventional hybrid with 26% amylose. The higher the amylose — a starch in the grain — the drier the rice will cook.
RiceTec also is testing a conventional early maturing high-yielding medium-grain hybrid.