UC evaluates wheats from 12 sites Often the first question in crop production is "What Variety Should I Grow?"

Choosing the right variety, or the misfortune of not selecting the right variety, has an impact on agronomic management decisions during the entire season. It can have even greater influence on crop marketing and potential profitability.

The difference in wheat yield from highest to lowest yielding variety in the Kern County test was 2,500 pounds per acre or more than $107 per acre difference in potential profit. An experimental variety could boast that another $10.

To a large degree, a variety's genetic pedigree controls grain quality and yield potential. Varieties differ in their resistance to diseases that are common in California such as strip or leaf rust, powdery mildew, barley yellow dwarf and septoria tritici blotch. They differ in their adaptability to the different climatic conditions and season length that occurs in California. They also differ in maturity, straw strength and end use qualities. New varieties are introduced yearly that have better qualities or higher yield.

University of California Cooperative Extension advisors and specialist conduct trials at 12 sites throughout the state to evaluate yield and other agronomic traits of commercially available varieties and advanced breeding lines.

Fifty-two common wheat varieties and 31 durum wheat varieties were tested in 2000. Multi-year, multi-location tests provide the best information on yield stability and potential. The multiple environments also provide an excellent opportunity for rating other agronomic traits. Relative yield, how one variety compares to another, may change from year to year. That is why it is critical to look at long-term data.

About 500,000 acres of common wheat were grown in California last season. Four varieties accounted for 7l percent of that acreage.

RSI-5, which was planted on more than 84,000 acres, had the highest yield of any commercially available variety. It has medium maturity with good straw strength. Its disease resistance is mixed. Yacora Rojo was planted on one-and-a-half times as many acres as RSI-5. Multi-year-location yield average is also not a high as RSI-5 and was particularly disappointing this year. It has similar disease resistance but better baking qualities.

Another top yielding variety is Bonus, first released in 1998. It has better disease resistance and excellent baking qualities. Other advanced lines, which may become varieties, offer higher yield potentials, improved disease resistance and good baking characteristics.

Durum wheat acreage was almost 100,000 acres. The end-product use of durum wheat, semolina, demands a high quality, high protein grain. Nearly 75 percent of all durum acreage is one variety, Kronos. In 2000, Kronos yielded very well and has good disease resistance. It also has excellent grain qualities for making semolina and pasta. Kronos consistently meets the quality standards to receive the premium durum wheat prices.

Many varieties are available. Care needs to be taken to select the best variety for one's farming operation. Results from the Kern County wheat variety test and other pertinent varietal information can be obtained from the UC Cooperative Extension office or on-line at http://www.co.kern.ca.us/farm/farm.html.