Semidwarf soybeans may be finding a niche

It is a trend that more soybean growers have been taking note of in recent years — shorter plants often yield as much or more than taller plants. This year was certainly no exception to that phenomenon as a cool, wet growing season in many parts of the state produced some pretty poor looking soybean fields that, in turn, produced some pretty surprising yields.

Taller soybean plants often look more promising, only to have wide internodes that result in fewer pods or they get too tall and suffer from lodging problems and yield loss. Richard Cooper saw these challenges, and the potential for shorter soybeans, back in the 1960s

“As a young soybean breeder, on my first job out of college at the University of Minnesota from 1962 to 1966, I was amazed when I first heard of grower contest winning soybeans yields of 80 to 100 bushels per acre, when the highest research plot yields were in the low 70s,” Cooper said. “ I wanted to see what 80- to 90-bushel per acre soybeans looked like.”

In 1967, Cooper moved to a position at the University of Illinois and started working with an Illinois grower who had won a soybean yield contest with an 80-bushel entry. Cooper started a research plot on the farm.

“I was amazed at what I saw. His soybeans reached a height of over five feet tall until they became severely lodged in a wind and rain storm,” he said. “It was obvious there was a serious lodging barrier to higher soybean yields in higher yielding environments.”

Taking a cue from wheat and rice breeding strategies, Cooper started investigating the viability of semidwarf soybean varieties with the hope of producing big yields while minimizing lodging problems. He started a breeding program for the effort in 1969 by crossing northern indeterminate-type soybeans with southern determinate soybeans and made high yielding selections with short internodes. One of the initial varieties was Elf.

“Like in wheat and rice, not only do you need semidwarf varieties, but you also must develop a crop management system that will maximize the yield potential,” Cooper said. “In a yield trial in Saybrook, Ill., Elf, when planted in seven-inch row spacing at seeding rates of 300,000 seeds per acre, yielded 80 bushels per acre compared to 49.1 bushels per acre for the conventional indeterminate variety, Williams, planted in 30-inch row spacing at a seeding rate of 150,00 seeds per acre.”

Soon after, Cooper transferred to the Ohio Agricultural Research and Development Center (OARDC) in Wooster as the ARS Soybean Research Leader where he released 14 additional semidwarf varieties. The last release was Apex in 2002 that has produced yields of 90 bushels per acre in Iowa and over 80 bushels per acre in Ohio.

A 10-year study in Hoytville showed an 11.8-bushel yield advantage with a semidwarf variety planted in seven-inch rows and a population of 300,000 seeds per acre over a conventional variety in 30-inch rows. The biggest yield advantage for the semidwarf soybeans was in years with favorable moisture. In 1979, the semidwarf soybeans yielded 84.1 bushels and the semidwarf yields were over 70 bushels three other years.

Yet, despite the promising potential of semidwarf soybean genetics, the effort was lost in the shuffle as seed companies got larger and Roundup Ready soybeans came along in the mid-90s, according to Jack Debolt, the manager of Ohio Foundation Seeds.

“When they were released, the semidwarf beans were designed to be planted in your highest yielding ground. They were promoted for planting with drills and a high population. Back then, most guys were still planting with planters and the drills were not as efficient as they are today. Farmers were used to planting 200,000 populations, but they were not interested in planting 300,000 and they were hesitant because they didn’t like how the short plants looked,” Debolt said. “There were times where the guys who planted them said they were their best yielding beans, but they never caught on. The area where they could really shine is the good river bottom ground. You plant them thick and it helps with weed control. And, they really don’t lodge. In all of the testing they did yield well. But, when Dr. Cooper was starting to release all of these, Roundup Ready was just hitting the scene and everyone obviously went with that. With the release of Roundup Ready soybeans the deck was stacked against these varieties.”

Now, though, there may be a niche developing for Cooper’s semidwarf soybeans. “There may still be two or three people in the state growing them and OARDC is still maintaining two or three of these varieties. Apex is around a 3.7 and the others are 2.9 and 4.0 maturity,” Debolt said. “This year Ohio Foundation Seeds made small increases of our semi-dwarf varieties that had been maintained by OARDC. We are going to see if there is any interest from seed companies in purchasing the Foundation seed of these varieties and producing certified seed. Dkg Seed Farms in Orrville has taken Apex and they are growing certified seed to sell to farmers in 2015. The initial production at Orrville is looking good and they are speculating that there will be some demand for these kinds of conventional varieties. What really would be beneficial is if soybean breeders would start crossing them with newer genetics. We have gotten calls, mostly from out of state, from companies interested in the varieties. These are conventional varieties and people are asking about them. If there is demand, there is real potential for high yields in the right environments with semidwarf beans.”

There seems to be increasing interest in conventional soybean seed that is becoming tougher to find.

“There is not a big of a supply of conventional bean seed out there,” he said. “If more people decide they want to plant non-GMO soybean seed, there are only five or six seed companies in Ohio that offer it.”

Interest in conventional soybean seed is partially being driven by challenges with resistant weeds.

“This could help with the resistant weed problem. By planting that thick it offers more competition with weeds and there is the potential for helping with resistant weeds,” Debolt said. “‘Your seed costs per unit are lower with the semidwarf seed, but if you plant at the higher population they end up being fairly close. When Roundup Ready came out, they had less cost in herbicides. Today that is not necessarily true. Since most farmers need a pre-emerge on their Roundup Ready soybeans, just like they do on their conventional beans, the herbicide costs are similar.”

While a niche tor Cooper’s soybeans may be developing, there will still be challenges for semidwarf varieties.

“We’re trying to resurrect these varieties but they will be facing challenges just like the last time around. They will have to be for niche markets. These are for guys growing conventional soybeans on good ground going for strong yields,” Debolt said. “The big companies already have strong breeding programs and probably will not be interested in incorporating any of the semidwarf genetics in their programs. I think soybeans generally have gotten shorter through the natural selection process. Standability is not quite the issue that it was years ago and the major companies are still going to focus on what they want to do.”

There is some work being done with the semidwarf soybeans by Ohio State University Extension as well. This year, though, they produced lackluster results. The semidwarf soybean plots were planted late, which really hurt them, said Laura Lindsey, OSU Extension soybean specialist.

“When semi-dwarf soybeans are planted late, they tend to put on a lot of succulent, vegetative growth. We planted the semi-dwarf soybeans on May 31, which was too late. They are fairly similar in height as the other varieties we planted. There is also some lodging because of the vegetative growth. There were some semidwarf soybeans planted in the Wooster area in June, and they severely lodged,” Lindsey said. “From my understanding, for semidwarf soybeans to do well, they need to planted by mid-May in 7.5-inch row spacing at 300,000 seeds per acre. None of these things happened in our trial, so it’s not a very good representation of semidwarf varieties. We intend to do the study again next year with a better planting date, hopefully, in 7.5-inch row spacing at 300,000 seeds per acre.”

Only time will tell if the semidwarf soybeans do find a fit in Ohio agriculture, Debolt said.

“It gets back to what kind of market you have for your soybeans. And, if you have a market for non-GMO beans then it is a good option. It depends on what the market is calling for,” Debolt said. “The semidwarf soybeans are something to think about, even though they are older varieties. If you are going to be growing conventional soybeans, they really do have strong yield potential under the right conditions. There are some highly productive soils in Ohio where the semidwarf varieties may perform well.”

Semidwarf yield data