Short Sunflower May Be Long On Advantages
Monday, February 3, 2003
filed under: Hybrid Selection/Planting
Plot trials indicate good moisture efficiency, quicker canopy, and better stem weevil tolerance
There’s an increased interest in short stature sunflower in the High Plains, and for good reason: indications are that it may use moisture more efficiently, and establish a quicker plant canopy. As well, it appears to be less susceptible to lodging and have better stem weevil tolerance, all the while demonstrating favorable yield and oil potential.
Short sunflower hybrids—about 38-42”, roughly half the size of a standard plant—are not new to the production scene, but improved genetics and breeding offer a better plant than past hybrids. “They didn’t catch on when they were introduced about 15 to 20 years ago, because of the small head that didn’t yield as well as standard height sunflower,” says Roger Stockton, KSU extension crops and soils specialist. “But it’s a better hybrid now, with about the same size head as regular sunflower. The only differences are that the internodes are about half as long and leaves are about 10 to 15% larger. Otherwise it’s the same as a standard sunflower plant.”
KSU has evaluated the newest short sunflower hybrid on the market in limited irrigation field trials last year. Seed in the trials was dropped with the goal of a 22,000 plant population at harvest, and managed the same as standard height sunflower. However, drought and insects reduced stand to 17,500 plants per acre with irregular spacing. The dryland (control) plots yielded a respectable 1,700 lbs, despite dry conditions. It appears to use water even more efficiently than a standard hybrid, says Stockton.
With 7.7” of supplemental water, the short stature sunflower produced over 2,500 lbs/ac with no insect control. In both treatments, a standard height hybrid had a harvestable yield of 1,000 lbs/ac less, due in part, to increased lodging resulting from stem weevil and stem borer activity, Stockton says.
Insect control clearly impacts yield: Stockton points to a two year study at Colby, Kans., by KSU crop scientist Rob Aiken and USDA entomologist Larry Charlet, which has shown a minimum 600 lb/ac yield increase resulting from adequate stem weevil control. “My best estimate of yield potential in my trial last year with adequate insect control is around 3,000 lb/ac for the short stature hybrid and 2,500 to 2,700 lb/ac for the standard height hybrid,” says Stockton.
He says that plant canopy closure was two weeks faster than standard size sunflower in the trial, offering an advantage in weed control and conservation of early evaporative surface moisture. With thicker, stronger stems, the short stature hybrid appears to have greater tolerance to stem weevil activity, and less susceptibility to lodging. “I know they stand better. You almost need a machete to cut through the stalks,” says Stockton.
Little (no pun intended) of the short stature sunflower is grown in the High Plains now, but there is a lot of interest in it. Triumph Seed expects to sell out of seed of its short stature sunflower this year, Triumph 667, a NuSun hybrid. “It has performed well in both dryland and irrigated trials. It ran 3,800 lbs with 48% oil in irrigated Thomas County (Kansas) trials last year,” says Maurice Haas, the company’s district sales manager in northwest Kansas.
Is this the wave of the future for sunflower hybrids? Actually, plant height has consistently been reduced over the years. Plant breeders report that some of their grower dealers will simply not accept hybrids that are considered “too tall,” even though the hybrid has lots of yield and agronomic promise. One breeder reported that a lot of good material was thrown away simply because it was several inches taller than what was considered acceptable.
At the end of the day, it all boils down to yield and a hybrid’s agronomic characteristics and height. Breeders are working on many fronts—disease and insect resistance, yield and oil content, herbicide tolerance, fatty acid composition—that are all important to the future of sunflower. Growers love choices, and short stature sunflower provides another alternative from a vast menu of different hybrids.—Tracy Sayler