(07/16/20) ST. GABRIEL, La. — The current pandemic is causing many changes in the way the LSU AgCenter conducts business, but getting information to those who need it has not.
The annual sugarcane field day couldn’t be held face-to-face as usual, but the researchers at the LSU AgCenter Sugar Research Station found a way to reach their target audience.
LSU AgCenter entomologist Blake Wilson explained the progress of his research on the sugarcane borer.
“We need high pest populations to get meaningful results,” he said. “Recent analysis of a nearly 20-year-old dataset shows that since the early 2000s, sugarcane borer populations along with insecticide use in sugarcane has declined by about 50 percent.”
This is attributed to a successful integrated pest management program, and Wilson noted three reasons for this decline.
“First is the introduction of the combine harvester in the 1990s, which harvests cleaner,” he said. “Second is the replacement of the highly susceptible LCP-384 variety with more-resistant varieties, which are now planted on more than 60 percent of our sugarcane acreage. And lastly, the replacement of pyrethroids with more biological control efforts.”
Wilson is also monitoring the Mexican rice borer in some off-station locations. Other off-site research is looking at pest such as the West Indian cane fly, he said.
AgCenter soil scientist Brenda Tubaña discussed the soil fertility research she is conducting in sugarcane.
To decrease financial losses to the growers, Tubaña’s research looks that the rate of fertilizer application along with different sources and delivery methods.
“There are 17 essential nutrients that we can talk about, but today we just want to talk about nitrogen,” she said. “The nitrogen cycle is very dynamic, which makes it one of the most difficult nutrients to manage.”
The recommendation to cane growers is to apply 60 to 120 pounds of nitrogen per acre to avoid deficiency in the plants and to avoid yield losses, she said.
Tubaña and her graduate students are using sensors to determine where nitrogen is needed to avoid unnecessary applications.
AgCenter weed scientist Al Orgeron said because sugarcane is a perennial, and it is hard to control other perennial weeds in the crop once they become established.
“Some of these weeds that we struggle with are bermudagrass, Johnsongrass and nutsedge,” he said. “The fallow period is the ideal time to try to manage these weed pests. This is where we make our largest strides, and it is the foundation of our weed management program.”
Growers have several options to control weeds during the fallow period, including cultivation and the application of glyphosate herbicides.
“When you spray glyphosate on a cane field, you’ll need to wait up to 10 days before you cultivate,” Orgeron said. “This gives the chemical time to translocate throughout the bermudagrass plant.”
Orgeron said glyphosate-tolerant soybeans are a great option for fallow-field production because they provide a better opportunity to control Johnsongrass and itchgrass.And it can also provide some extra income.
Sugarcane breeder Collins Kimbeng discussed some of the work that goes on in the variety development program that many growers may not be aware of.
“Genetic variation is the most important ingredient in any variety development program,” he said. “We create the variation by shuffling the genes in the male and female plants.”
Kimbeng said it is a long process to get from the beginning processes in plant breeding to the developed variety. But it all begins with a single seed or seedling.
Plant breeder Michael Pontiff discussed the development of the latest AgCenter sugarcane variety.
“Our latest variety, Ho 13-739, has taken 12 years to develop, and we voted unanimously to accept it mainly because of the early sugar production,” he said. “It also has good tonnage and is resistant to both smut and leaf scald.”
After the Nov. 13 freeze in 2019, Ho13-739 proved to be cold tolerant, unlike some of the older varieties.
AgCenter plant pathologist Jeff Hoy is looking for ways to manage disease through the introduction of resistant varieties.
“The field test that we do, even the greenhouse tests, are costly in terms of space and time. And they tend to be erratic,” he said. “Variable environmental conditions can affect the outcome.”
Hoy and his team have begun looking at a new technology that uses molecular markers to identify disease resistance.
“Yield is the No. 1 priority for the industry,” Hoy said. “Yield is also the No. 2 and No. 3 priority.”
AgCenter plant molecular biologist and geneticist Niranjan Baisakh said the main goal of his research is to devise molecular tools to complement the sugarcane breeding program.
“The first thing we want to do is to determine the genetic diversity in the sugarcane varieties that are already present in Louisiana sugarcane,” he said.
Selection of varieties by what is seen in the field can be deceiving because environmental conditions may not allow for the expression of a certain disease or trait.
The virtual field day also included talks by Bill Richardson, LSU vice president for agriculture; Mike Salassi, AgCenter associate vice president for plant and animal sciences; Jim Simon, general manager of the American Sugar Cane League; and Mike Strain, commissioner of the Louisiana Department of Agriculture and Forestry.
The internet presentations at this year’s virtual sugarcane field day are available at www.LSUAgCenter.com/sugarcanefieldday. Viewers are also able to watch the presentations on YouTube.
LSU AgCenter plant pathologist Jeff Hoy speaking at a past sugarcane field day. This year, the event was held in a virtual format due to the coronavirus pandemic. Photo by Johnny Morgan/LSU AgCenter