Steven Linscombe | 9/16/2013 11:17:45 PM
The Rice Research Station has been developing and releasing new rice varieties since it was established in 1909. For almost as long, the station has specialized in the production of foundation seed of those varieties. Foundation seed is the seed that the research station releases to the rice industry to provide beginning seed stocks for the future of new and existing varieties.
Production of foundation seed starts with the development of a new rice variety. This process requires meticulous measures to purify seed through the various generations as an experimental line is being tested to judge whether it merits release as a new variety for commercial production. The average time from start to finish of this process is about seven to eight years, from a cross being made to a variety being formally released and foundation seed being made available by the LSU AgCenter.
Most Rice Station varieties have been developed using a process called the pedigree selection procedure. Using this system, we first make a cross between two diverse germplasm lines. We then harvest the cross seed and plant them to produce F1 plants. Seed from the F1 plants are harvested and then used to plant bulk F2 populations. Rice Station breeders select panicles from the most promising F2 plants. These panicles (and all subsequent generations) are planted as head rows, which are rows of plants all derived from the same rice panicle (head) from the previous generation.
In each generation from the F3 on, the most promising head rows are harvested, and the remainder rows are discarded. When a head row displays enough uniformity to be considered a candidate for yield testing, that row is bulk-harvested after 10 panicles have been hand-picked from the row. If that line makes it into a yield test the following growing season, seed from the harvested panicles are also planted as head rows.
Each year after a line proves its potential for advancement in yield testing, panicles are harvested from the head rows and planted the following year. Prior to harvesting these head rows each year, they are evaluated for purity and uniformity. Those that don’t display the proper characteristics are removed from the population before harvest. By the time an experimental line has proved its muster and is considered a candidate for release, it has been head-rowed for several generations, which serves to increase uniformity and purity.
The last stage before foundation seed production is a large head row increase that can vary from 1,000 to 4,000 head rows. Often, this increase is grown at the winter nursery in Puerto Rico. After a final rigorous evaluation, this head row increase is bulk-harvested and turned over to the Rice Station’s Foundation Seed Program.
Released varieties are also head rowed each year to provide purified seed for future foundation seed production. Some varieties last only a few years but others stick around longer. An example here is the variety Cypress, which was first released in 1992 but was still being grown as foundation seed in 2012.
Mr. Larry “Smokey” White has been in charge of the station’s foundation seed program for most of his 33-plus-year tenure there. He has been responsible for establishing the station’s reputation as the premier rice foundation seed program in the United States. Recently, Mr. Rick Zaunbrecher has joined the program to learn the tricks of the trade to maintain this program into the future. Once this head row seed is turned over to their program, it is then used to plant increase fields of foundation seed. The head row seed is normally planted at a seeding rate of approximately 35 to 40 pounds of seed per acre. These fields are grown similarly to any commercial rice production fields with typical fertilization, insect, weed and disease control practices employed.
Then, as the fields begin to head, the roguing process starts. Roguing involves walking the field looking for nontypical plants that could be a genetic off-type or a volunteer plant. These plants are physically removed from the field. Fields are typically walked and rogued at least three times before harvest. In addition, the fields must be inspected by a Louisiana Department of Agriculture and Forestry (LDAF) inspector before harvest as part of the certification procedure.
The field is harvested using a squeaky clean combine to ensure purity. It normally takes several Rice Station personnel two to three days to completely tear down and clean a combine between harvests of foundation seed fields. Once harvested, the seed is delivered to the station’s foundation seed drier, which has also been meticulously cleaned to ensure purity. There, it is dried and stored to await processing. In the fall, each variety is cleaned and packaged using state of the art equipment. After cleaning, an LDAF inspector collects a seed sample, which is submitted to the LDAF seed lab in Baton Rouge and subjected to a number of tests, including germination and purity. Foundation seed can only be distributed if it passes this rigorous testing program.
Foundation seed is the backbone of the rice industry. This seed is a first step in assuring that the seed a grower purchases to plant his crop is the variety he chooses and is of high germination and free from noxious weeds such as red rice. The Rice Research Station has long prided itself in producing superior foundation seed.
Permission granted, September 16, 2013 by B. Leonards (LA Farm & Ranch) to republish article on www.lsuagcenter.com