Kenneth Gravois

Successful ventures have defining moments. An early one for the Louisiana sugar industry occurred at a meeting of the Louisiana Sugar Planters Association in January 1878 when Joseph Brent stated this challenge: “The Louisiana sugar industry is a creature of government protection; and even this protection will prove insufficient to sustain it unless it be aided by all of the resources of modern science.”

Then, as today, the Louisiana sugar industry needed innovation to compete; the industry needed access to new technologies and most importantly, higher sugar yields. The Louisiana Sugar Experiment Station was started by local planters in August 1885 with a mission closely linked to sugarcane variety introduction in the early years and variety development that continues today. From its origins, the LSU AgCenter Sugar Research Station has maintained close working relationships with the U.S. Department of Agriculture and the local Louisiana stakeholders, today through the American Sugar Cane League.

One important sugarcane variety, L 01-299, came about through the efforts of AgCenter sugarcane breeders Kenneth Gravois and Keith Bischoff. The process began with a cross between L 93-265 and LCP 85-384, a commercial variety that once commanded 91 percent of the Louisiana sugarcane acreage in 2004. The timeframe from crossing to final release of a commercial sugarcane variety is long — 12 years plus a few years for producers to ramp up producing seedcane to plant on significant acreages. L 01-299 was released for commercial sugarcane production in 2009.

Early in the variety testing process, L 01-299 exhibited high yields and superior stubbling (ratooning) ability to produce subsequent crops (Table 1).

Table 1. Sugarcane data from third-year stubble outfield variety trials conducted at six locations across south Louisiana during 2017.

Sugarcane is a perennial crop, with production across many growing seasons from a single planting. A sugarcane crop cycle consists of the first crop, referred to as a plantcane crop, and a varying number of subsequent stubble crops. Planting is one of the most expensive and onerous aspects of the sugarcane farming operation, and extending the number of stubble crops greatly improves profitability for Louisiana sugarcane producers.

In addition, L 01-299 has good sucrose content and an erect growth habit and is the only commercial sugarcane variety in Louisiana to possess the Bru1 gene, which confers resistance to brown rust disease. Cold tolerance is another positive for the variety. No variety is perfect; L 01-299 establishes slowly after planting and is susceptible to brown stripe disease. With this trait ensemble, producers have quickly adopted the variety as a primary choice for planting (See Table 2 below).

To understand the success of L 01-299, one must understand the development of its parent LCP 85-384. Louisiana was suffering severe yield losses because of sugarcane mosaic, a viral disease. The commercial sugarcane breeding program in Louisiana had exhausted all options for resistance to this disease. The solution lay in a parent-building effort conducted by geneticists at the USDA Agricultural Research Service Sugarcane Research Unit in Houma. This basic breeding effort has access to clones of the wild species of sugarcane, Saccharum spontaneum. At first glance, these clones offer little value to a commercial sugarcane industry. But clones of S. spontaneum have genes for disease resistance, cold tolerance, stubbling ability and improved yield. By crossing commercial or near-commercial sugarcane clones with these wild clones and backcrossing for two to three genera­tions, near-commercial sugarcane parents are made available to the commercial sugarcane breeding programs.

In the October 15, 1967, issue of the Sugar Bulletin, sugarcane breeders shared a vision of what basic sugarcane breeding efforts could offer the Louisiana sugarcane grower. They dreamed of higher tonnage, improved cold tolerance, longer crop cycles, less cultivation and resistance to a disease for which they had no answer. The path forward would be long but offered many benefits.

It is exciting to think what the next 50 years of sugarcane breeding will bring to the Louisiana sugar industry. With the release of L 01-299, Louisiana’s sugarcane producers are living the dream.

Kenneth Gravois is the Denver T. Loupe-ASSCT Sugar Heritage Professor in Sugarcane Research and state sugarcane specialist at the Sugar Research Station.

(This article appears in the winter 2018 issue of Louisiana Agriculture magazine.)

L 01-299 has been a popular choice among growers during recent planting seasons. Photo by Al Maclean

Figure 1. Sugar yield (lbs./acre) in Louisiana from 1967 to 2017. Major sugarcane varieties of the era are listed at the top.