CLL15 and CLL16: A Dynamic Duo for the North Delta

02/18/2021

Upper Delta rice farmers looking to maximize performance while spreading risk planting multiple varieties have a powerful one-two punch combination with Horizon Ag CLL15 and CLL16 in 2021. Both are Arkansas-bred Clearfield® varieties proven to have strong yield potential and excellent milling characteristics, in addition to broad spectrum blast resistance.

We’ve learned a lot about managing these two high-performing varieties in research trials and real field conditions. We are very confident in the superior performance and return on investment potential that both provide compared to conventional varieties and FullPage™ and Clearfield rice hybrids suited to the region.

CLL15 was launched commercially last season. It is a semi-dwarf, long-grain rice variety that has very good standability and vigor. Farmers can maximize its performance potential by seeding it early in the optimum planting window. It’s a strong planting partner for new CLL16, a traditional Arkansas-type long grain that has been described as offering “the complete package” for yield, quality and blast resistance. CLL16 is broadly adaptable and has proven to perform well even when planted later in the optimum planting window.

Dr. Tim Walker, Horizon Ag general manager, noted that rice farmers who have experienced challenging planting delays in recent years are hoping for a return to some normalcy. “After the cold snap this week passes and we begin to warm up, there is a good chance we’ll see an early spring. A lot of land has been prepped and farmers are ready to take advantage of what they hope will be a timelier planting opportunity. If that happens, it sets up well for starting with CLL15 and then shifting to CLL16.”

That early optimum planting window varies by location, typically beginning around March 20 in the Grand Prairie region and April 1 in the Jonesboro, Arkansas area. Keys to managing for success with an early planting include using treated seed and being timely with fertilizer applications, particularly nitrogen.

Planting early is particularly important for CLL15. In 2020, some Arkansas farmers who planted CLL15 later than the ideal seeding time, due to persistent adverse weather, saw Cercospora impact yields. Cercospora, which is typically more prevalent in the Coastal Production region, developed late and may have been exacerbated by the hurricanes that sent high winds and rain across much of the region. It reportedly was an issue with both hybrids and varieties.

Keys to minimizing the threat of Cercospora in the future are avoiding late planting of CLL15, including an application of propiconazole fungicide at late boot to boot split if planting in a later window, and making sure potash levels are adequate.

CLL15 is an earlier maturing variety, reaching 50 percent heading in 81 days, similar to CL151, a popular, high-yielding but older Clearfield variety. Unlike CL151, however, it is resistant to blast, containing both the Pi-ta and Pi-km blast-resistant genes. At 38-inches tall, it has much better standability than CL151.

North Delta farmers also are showing a high level of interest in CLL16, the latest Horizon Ag Clearfield variety that has shown excellent rough rice yields, averaging higher than Diamond in university tests. CLL16 is a very stable variety with an early maturity date, averaging 86 days to 50 percent heading, similar to CL172 and Wells, and about four days earlier than Roy J. Plant height is 42 inches with a 36-inch canopy, similar to Diamond. Grain weight and size are similar to Diamond, with nice long, plump kernels. It has typical Southern U.S. long-grain cooking quality. The plants have very strong straw, indicating good lodging resistance.

CLL16 has the Pi-ta and Pi-km blast-resistant genes, is rated moderately susceptible to false smut and is susceptible to sheath blight. It is also moderately resistant to Cercospora.

For more information about Clearfield rice varieties CLL15 and CLL16, see your Horizon Ag District Field Representative or rice seed dealer. You can also learn more about Horizon Ag varieties at our website, horizonseed.com.