Variety selection is critical to wheat profitability in South Carolina, because we are so dependent on varietal resistance for disease and insect management. No variety is perfect, but the ideal variety for our area would have consistently high yield potential, high test weight, Hessian fly resistance, powdery mildew resistance, leaf rust resistance, and excellent straw strength.
When looking over the newly available wheat varieties, South Carolina growers can thank small grain breeders for coming to the rescue once again. Resistance to leaf rust and Hessian fly has declined in some of our long term standards.
Let's look at what's available in newer wheat varieties.
Pioneer 26R61 was new last year. This variety has had excellent resistance to Hessian fly, both in our tests at Blackville and on-farm. It has high yield potential, with excellent rust resistance and test weight. Pioneer 26R61 is a tall wheat, but has good straw strength. This variety should do well anywhere in the state, but growers in the Pee Dee region may be especially interested because Pioneer 26R61 has demonstrated excellent fly resistance in the northern coastal plain.
Pioneer 26R46 was also new last year. It has shown excellent fly resistance at Blackville. Yield potential is a bit higher than 26R61, but test weight is not quite as high. Rust resistance in 26R46 is also not as good as 26R61.
Pioneer 26R24 is new this year. It has only moderate fly resistance, meaning heavy infestations will cause significant yield loss. Rust resistance is not as good as either 26R61 or 26R46, so we feel it has less potential under South Carolina conditions.
AGS 2000 is a new variety from the University of Georgia and University of Florida breeding programs. AGS 2000 has consistently high yield potential and good test weight. It has demonstrated excellent leaf rust resistance. It has also shown excellent Hessian fly resistance at Blackville, but is probably more susceptible in the Pee Dee area. Height is medium and straw strength is excellent. AGS 2000 is an early/medium maturity wheat. It can head one to two days before Pioneer 2684, so it is susceptible to spring freeze injury if planted too early. This variety has a distinctive, bluish-green head color. AGS 2000 should do particularly well in our southern coastal plain.
USG 3209 is a new variety, originally out of the Virginia Tech program. High yield is its claim to fame. It has been near the top of many yield trials across the Southeast, including our test at Blackville. Test weight is good, not exceptional. It has good powdery mildew resistance but only fair leaf rust resistance. It is Hessian fly susceptible, but topped our yield test even with some fly damage. USG 2000 has medium height and good straw strength. This is a medium maturity wheat. We normally aren't interested in new varieties with fly risk, but USG 3209 has exceptional yield potential.
These new varieties will probably be in very limited supply this year. When trying a new variety, it's a good idea to keep most of the acreage in a proven standard. Among the standard varieties, Pioneer 2684 has stayed near the top of our yield trials and has excellent test weight. It still shows good fly resistance "south of the lakes", but is more susceptible in the Pee Dee region. Rust resistance in 2684 has declined from a good to fair rating.
Coker 9663 has high yield potential with good test weight and this variety still has good leaf rust resistance. Coker 9663 is susceptible to Hessian fly in the Pee Dee region, but has shown some resistance in the Southern Coastal Plain. Coker 9663 is prone to lodging.
Coker 9704 and Coker 9803 are very similar varieties adapted only for the northern half of the state. Both of these varieties are susceptible to Hessian fly and powdery mildew. Coker 9704 and 9803 have excellent test weight and good rust resistance.
Coker 9835 and Coker 9134, until two years ago, were nearly immune to Hessian fly in the Southern Coastal Plain area of South Carolina, but both fly resistance and rust resistance have declined to the point where we need to move away from these varieties unless the grower plans on protecting them with foliar fungicide and accepting more Hessian fly risk.
Although resistance is the ideal way to control Hessian fly, susceptible varieties can be protected with in-furrow Di-Syston or Thimet (phorate) treatments. Another option is Gaucho seed treatment. None of these products give 100 percent control, but they suppress the fall seedling infestations that cause the most damage and yield loss.
The 2000 Wheat Cheat Sheet, available in all counties, has the latest ratings for pest resistance, yield, test weight, and other agronomic characteristics for these and other varieties in South Carolina.