Plant Breeder Looks For The ‘Perfect’ Soybean
BOSSIER CITY, LA.
The “perfect” soybean would have great disease and herbicide
resistance, excellent drought and salt tolerance, be able to withstand
insect pests and be high-yielding. And LSU AgCenter plant breeder Blair
Buckley is on a quest to find it.
Since 2007, Buckley has been making soybean crosses at the Red River
Research Station near Bossier City to find this elusive variety.
Ultimately, the perfect soybean may be unattainable, but Buckley is
confident that improvements can be made on existing varieties grown in
Louisiana.
“So much of plant breeding is a numbers game. There is a lot of
material to go through, and much of it does not make it through to the
next level,” Buckley said.
It takes a minimum of 10 years to develop a new variety, he said.
During this time period, plants are bred and trials are conducted in the
field. These field tests must be repeated over the course of several
growing seasons to ensure the validity of the findings.
One of the biggest concerns for Buckley and soybean growers is
disease. Cercospora blight, caused by a fungus, is the major disease
that has been plaguing producers not only in Louisiana but in other
Southern states. Disease symptoms first appear as petiole lesions and
purplish-bronzing of upper leaves at the late R5 and early R6 soybean
growth stages.
Though major symptoms appear late in the season, infection occurs
earlier, and the fungus remains latent for a period of time. Severe
infections can result in significant defoliation, substantial yield loss
and reduced seed quality.
Soybean plant breeders evaluate hundreds of varieties every year in the quest for an improved soybean variety.
Photo by Bruce Shultz
The seed disease purple seed stain is also caused by the same fungus.
“Fungicides have not been very effective in fighting Cercospora, so
that means yield loss can be significant,” Buckley said. “We are placing
an emphasis on finding varieties that show some resistance to this
disease.”
Buckley is examining a few hundred lines and indicated that four to
six have shown promise against Cercospora. While not symptom-free, the
varieties display symptoms that have been less severe and have come
later in the growing season, thereby lessening potential yield loss.
Another trait high on Buckley’s list is drought tolerance. Hot and
dry conditions are common throughout Louisiana’s growing season.
“We are looking at material that has shown promise in combating
drought-like conditions. This material has slow-wilting lines and
conserves moisture better,” he said.
A growing concern is that major aquifers across the South are being
depleted. With soybean acreage trending higher, reducing the amount of
irrigation statewide can reduce the pressure on these vital aquifers
without decreasing the potential yield of soybeans.
Another trait garnering attention from Buckley is salt tolerance.
Growers in the north central and northeastern parts of Louisiana have
seen high salinity levels in their irrigation water. This has led to
reduced yields for farmers who have encountered this situation.
For growers who have access to surface water for irrigation, using it
may be a solution. For those who must rely on well water, a
salt-tolerant soybean variety is essential to alleviating the problem.
Another recent trend in soybean production has been the increasing
popularity of Group IV and V beans. For many years Groups VI and VII
were dominant. The switch to Groups IV and V is primarily based on their
shorter production schedules. For this reason, Buckley is focusing much
of his research on Groups IV and V.
Many growers want the shorter production timeframe to reduce risk and
accommodate their farming operation. For example, sugarcane producers
growing beans on fallow sugarcane land want those beans harvested so
they can begin planting cane in August and September. Earlier-maturing
varieties also reduce the risk of being damaged by a tropical storm.
Even with all the attention given to these traits, Buckley said yield
is still dominant. “If it doesn’t yield well, nobody is going to grow
it,” he said. ∆