SMALL GRAINS UPDATES

Transcription

1 VARIETY RELEASES SMALL GRAINS UPDATES Dr. J. W. Johnson, Department of Crop and Soil Sciences, Griffin Campus, Griffin, GA USG 3592 is a high yielding, excellent test weight, medium maturing and tall soft red winter wheat variety. It is resistant to currently predominate races of Hessian fly, leaf rust, septoria nodorum blotch, and soil-borne mosaic virus. It is moderately resistant to stripe rust and powdery mildew. USG 3592 is marketed by UniSouth Genetics. Horizon 321 is a winter oat which performs well for both grain and forage production in the Southeast. It is high yielding, excellent test weight, good crown rust resistance, and medium maturing. AGS 104 is a rye for early season forage productions that will work well in blends with ryegrass for long season forage production with excellent leaf rust resistance. In appearance, AGS 104 most closely resembles Wrens 96 and is slightly later than Wrens 96 in maturity, but similar in height and seed appearance. AGS 104 has been released exclusively to AGSouth Genetics. 342 (likely will be referred to as Trical brand 342) is a triticale which performs well for grain production. It is high grain yielding, medium maturing and good test weight. Releases by private companies for production in Georgia: AgriPro Panola and Hornbeck HBK 3266.

2 DISEASES John D. Youmans, Department of Plant Pathology, Griffin Campus, Griffin, GA Once again the wheat growing season presented Georgia wheat growers with a challenge. The fall temperatures were mild with the majority of colder winter temperatures occurring later in December. This encouraged aphid activity, and from the Piedmont and north to Calhoun Barley Yellow Dwarf Virus (BYDV) was severe. Lesser amounts of BYDV were observed at Plains and Tifton. A true yield loss number is difficult to pinpoint, but the losses due to BYDV were real this year, from the Piedmont and north. Virtually no stripe rust was found in the state, this after Georgia had widespread stripe rust last year in commercial fields. Leaf rust on wheat was also not an issue this year thanks in part to an extremely dry spring with rainfall well below the average and with more resistant cultivars being planted in commercial fields. Additionally, many growers had applied fungicides earlier after finding powdery mildew in fields. Rust was observed on rye grain plots in Tifton earlier in the season but was not a yield reducing factor. Crown rust on oats was low as well this season. Fusarium foot rot was sporadically found in southern Georgia and may have contributed to the early decline of some fields. Take-all may have played some role in this observed decline as well. Powdery mildew could have been a huge yield reducer this season but again with the drier spring and early fungicide applications most epidemics were controlled. Mildew was observed at fairly high levels across a wide range of cultivars early in the season at Plains and Tifton. Glume blotch (Stagonospora) on heads and leaves was at some of the lowest levels in years. This again due to the extremely dry conditions observed within the state this year. Again the single most important piece of the disease management puzzle is the cultivar selection.

3 INSECTS G. David Buntin, Department of Entomology, Griffin Campus, Griffin, GA The variety test was planted in the fall of 2003 at the Southwest Branch Experiment Station near Plains and was sampled for Hessian fly, Mayetiola destructor, infestations in late April A second test was conducted at the Bledsoe Research farm near Griffin, but infestations were too low for meaningful comparisons of varieties. Results of the test at Plains are shown in the next table. Several varieties showed good levels of Hessian fly resistance. Varieties marked by rated as resistant in this year's test but were susceptible in previous trials. 'Pioneer Brand 2684', Roberts, and Fleming contain resistance genes but are susceptible in Georgia and will not stand up to a heavy infestation. Varieties with good resistance in southern GA may not be resistant in northern GA because of the presence of biotype L in northern GA. The only currently available variety with biotype L resistance is 'Pioneer Brand 26R61'. Both rye and oats are good Hessian-fly resistant alternatives to wheat for forage production, because rye is highly resistant, and oats are immune to the insect. In general Hessian fly infestations and damage were low in 2003/2004. Warm weather also encouraged aphid populations in the winter months throughout the state. Aphids caused direct injury to wheat and also transmitted barley yellow dwarf virus (BYDV), which caused high levels of symptoms and losses in some areas. Although the level of expression of symptoms varies between varieties, no varieties are truly resistant or tolerant of BYDV infection. Systemic insecticide seed treatments and properly timed foliar applications of insecticides can reduce aphid numbers and minimize BYDV incidence. The cereal leaf beetle now is established throughout northern and most of southern Georgia. Populations continue to increase and caused noticeable damage this year in the Coastal Plain region. Larvae and adults are present in the spring during grain filling where they remove the upper leaf surface and chew elongated holes in leaves. Populations in most areas still are below the treatment threshold of 0.5 larva or adult per stalk. However, damage was very evident in the northwestern and central Piedmont regions of the state as well as the Upper Coastal Plain from Milledgeville to Statesboro with some fields needing treatment with an insecticide. Cereal leaf beetle can be effectively controlled by a number of insecticides when applied to active larvae. Consult your local county extension agent and 2004 Georgia Pest Management Handbook for a list of recommended insecticides and for management practices for these and other insect pests of small grains.

4 Hessian fly infestations in entries of the Georgia State Winter Wheat Variety Trial at Plains, GA, late-planted in Entry % infested stems 1 HF larvae & pupae per stem SS a* 1.08* AgriPro Savage 40.0 ab* 0.67* NK Coker abc* 0.64* GA A a-d* 0.67* NC b-e* 0.75* AR b-f* 0.40* GA E b-g* 0.37* Vigoro Tribute 18.7 c-i* 0.35* Pioneer Brand 26R c-g* 0.21 GA A d-j* 0.27* Fleming 17.3 d-j* 0.25* AgriPro Crawford 17.3 d-j* 0.27* GA E e-m* 0.19 AgriPro Panola 14.7 e-k* 0.21 Croplan Genetics 514W 14.7 e-k* 0.19 HBK e-l* 0.23 NC Neuse 12.0 e-m* 0.12 GA E e-m* 0.19 SS f-m* 0.16 GA E g-m 0.13 Roberts 8.0 h-n 0.21 GA E h-o 0.12 USG h-o 0.09 GA931630E h-o 0.09 NK Coker h-o 0.12 Pat 6.7 h-n 0.07 GA E l-o 0.05 Pioneer Brand 26R l-o 0.07 USG i-o 0.11 GA E j-o 0.08 Pioneer XW02M 5.3 j-o 0.08 UGA931233E k-o 0.12 GA A mno 0.04 McCormick 4.0 k-o 0.09 NK Coker 9375 (NK B960457) 4.0 j-o 0.04 AGS k-o 0.07 AGS k-o 0.05 GA E l-o 0.05 Croplan Genetics no 0.01 Pioneer Brand 26R no 0.11

5 Hessian fly infestations in entries of the Georgia State Winter Wheat Variety Trial at Plains, GA, late-planted in Entry % infested stems 1 HF larvae & pupae per stem Continued: GA E31 0 o 0 GA E35 0 o 0 Pioneer Brand 26R61 0 o 0 GA A25 0 o 0 GA A41 0 o 0 GA E38 0 o 0 LSD (0.05) LSD (0.1) Means followed by the same letter are not significantly different (P = 0.05, LSD). * Entry significantly different than zero (P = 0.10). Entry not significantly (P = 0.1) different than zero, but rates as susceptible in previous trials.