Selecting a Wheat Variety
(By T. Walters and R. Sears, 1986. Revised by R. Bowden)
Variety selection can make the difference between profit and loss, so deserves careful attention each year. Obviously, the primary objective is to pick varieties that will give high per acre yields and the highest possible net income, but this is not a simple matter.
Varieties do differ in grain yield potential. During the past 20 years, yields have increased approximately one-half bushel per acre per year, due to the release of new improved varieties. Consider choosing new released varieties on a regular basis, perhaps every 3 to 4 years, to take advantage of the higher yield potential of new varieties.
High yield potential should not be the only yardstick for varietal selection, since there are many factors that influence actual yield in the bin. Variety strengths (e.g. yield potential, pest resistance, or strong straw) should be matched against expected field problems (e.g. soilborne mosaic, Hessian fly infestation, or lodging) so as to get the best possible protection against hazards while maintaining high yields. Since no perfect varieties have been developed, this usually results in compromise and assumption of risks in order to gain advantages in other areas. Several different varieties should be planted in order to hedge against some of the unpredictable weather and pest problems.
A complicating factor in recent years is the growing number of choices. It takes more time now to sift through characteristics, comparative performance data, seed sources, and relative prices than it did a few years ago. The Federal Plant Variety Protection Act stimulated private breeding and sales of variety seed by providing a "plant patent" protection to originators. Hybrids have their own built-in "patent" protection because new seed must be purchased for planting each year. In addition, Great Plains public breeding programs have been active in releasing new varieties in recent years.
Since it is not feasible for growers to individually test all varieties on the market, they must rely on other sources for their information. Sources include their own neighborhood experience, county agent demonstrations and tours, Experiment Station field days and test information, seed company advertising, demonstrations, and meetings. It takes considerable effort, careful study, and good judgement to make intelligent choices from all of this information. Use your own experience with the varieties you have personally grown as a base for comparisons.
The Experiment Station role has changed over the years. The old listing of "Recommended Varieties" by areas was discontinued when so many varieties became available, resulting in a large list of variety names that by itself had little meaning. Instead, varieties are compared in scientifically conducted yield tests at 16 sites over Kansas each year, and the results are distributed to the public soon after harvest. In addition, many greenhouse and laboratory tests contribute information on pest tolerance, baking quality, and other factors. Several publications summarizing the above tests are available to growers at all county Extension offices. Several are also available in electronic versions:
Early maturing varieties are more likely to escape damage from hot winds, drought, and rust. They are more subject to late spring freezes, however. Producers with large acreages can spread harvest by using varieties of differing maturity. Varieties or hybrids that flower earlier than Jagger or later than Arapahoe may run into production difficulties in Kansas from frost damage to heads and late-season hot winds, respectively.
Wheat is most subject to damage from cold temperatures
Varieties do differ in their susceptibility to freeze damage. For example, Vona is one of the least winterhardy varieties grown on a significant acreage in Kansas in recent years. Scout and Scout derivatives (Eagle, Sage, Larned, etc.) are hardy enough for most Kansas winters. The hardiest varieties include Arapahoe, Karl 92, Tomahawk, Champ, and 2137.
Genetic resistance to insects and diseases is an excellent control method when such resistance is available. Hessian fly, wheat streak mosaic, soilborne mosaic, stem and leaf rusts, speckled leaf blotch, tan spot, and other diseases can and do cause serious losses in the Kansas wheat crop. Use of resistant or tolerant varieties, plus good cultural practices, can minimize losses. Many good soilborne mosaic resistant varieties have been released in recent years, including 2163, Karl 92 and Tomahawk. Ike, Pecos, and 2163 have good Hessian fly resistance.
Since wheat is harvested with the combine and harvesting must wait until the crop is ripe, varieties that do not lodge or shatter are desired. The shorter "semidwarf" wheats usually stand better than standard height varieties. Under dry conditions where deep planting is necessary, the short coleoptiles (sprouts) of some of the semidwarfs may cause a problem in obtaining good stands.
The major use of the Kansas wheat crop is as a bread wheat for human consumption. It therefore is important that the grain be of a quality needed by the millers and bakers to produce a quality end product. Quality is determined by variety as well as by growing conditions. Since quality is important, it is essential that producers consider quality in selecting varieties to grow.
Many soils in Kansas are becoming more acidic due to the use of nitrogen fertilizers. Acidic (low pH) soils have more free aluminum which can burn root tips and lead to poor vigor. Many varieties such as 2163, 2180, and Jagger show good tolerance to aluminum toxicity and so can tolerate low pH soils.
Many newer semi-dwarf varieties have short coleoptiles that cannot emerge from deep planting. For example, the coleoptile of Vista is only 2.5 to 3.0 inches long. On the other hand, Larned, Longhorn, and Thunderbird have coleoptiles over 4 inches in length. These long coleoptile varieties are better for deep planting.
Many Kansas wheat growers gain extra income by grazing livestock on wheat fields in the fall, winter or early spring. There are large differences between varieties in the amount of forage produced. Varieties with the best grazing potential include Longhorn, Jagger, and AP7301. Awnless varieties like Longhorn or Voyager can be grazed after heading in the spring because there is reduced danger of awns injuring livestock.