August 25, 2011

2011 Results May be Atypical

The publication of the Fall Seed Guide (EC103), now available from UNL Extension, concludes the 2011 Wheat Variety Testing season, one which was atypical in many ways.

The season started with unusually dry conditions that required wheat seed to be dry planted at most trial locations. Not surprisingly, emergence was uneven and plants achieved little above ground biomass before freezing. In several trials we thought the field was lost; however, favorable spring rains helped plants compensate and led to aggressive tillering and grain development. Rainfall amounts, timing, and distribution were very conducive to wheat growth.

Grain size and protein percentage at several sites were influenced by unusually wet conditions as well as hail damage. This was discussed in part in another CW article, Wheat: Recapping 2011 and Selecting Seed for the 2012 Crop. Data for several Panhandle sites isn’t available due to crop damage.

Evaluate Data from Multiple Years and Sites

When selecting seed for the next season, dryland producers are encouraged to look at the long-term averages and results from last year as well as this year. The Wheat Variety Testing Page includes results from last year just below the postings for this year. Results from previous years can be viewed at the archived results page; however, the Fall Seed Guide is the only source of performance across sites and performance across years.

With an unusual crop season like we saw this year, it is difficult to judge whether the performance of a variety is atypical due to the season or whether the results would be repeated. Therefore, it is important to use the Fall Seed Guide to evaluate closely how a given variety performed across sites and across years. The Fall Seed Guide contains means for certain varieties for up to five years. Most wheat variety testing regions have more than one testing site. Across location means performance of a variety can be compared across multiple sites in an area.  Information posted in associated sites such as the Wheat Virtual Tour and the Winter Wheat Variety Selection Tool are based on the information in the Fall Seed Guide. 

The Seed Guide and postings on the Variety Testing web page provide key characteristics for each variety, including yield, seed size, test weight, and grain protein at locations tested. Important additional information such as relative values for maturity, winter hardiness, straw strength, coleoptiles length, and disease and insect resistance and relative ranking in performance for yield, bushel weight and protein are found in the Fall Seed Guide.

Information on relative ranking for key response parameters like yield, protein, and bushel weight shown in the seed guide are important in years like this. The table shows the relative ranking of performance across locations where the variety is tested. The ranking can be used to judge the relative stability in performance across test locations.

Soil type and management factors such as plot history, crop rotation, previous crop, residue management, and tillage have a significant effect on varietal performance in terms of yield, grain quality, and disease reaction. The Fall Seed Guide provides management information and plot history for all testing locations. Producers are encouraged to use this information to assess how a variety is apt to respond to their farm condition and management.
The Fall Seed Guide also contains additional information from the Nebraska Crop Improvement Association on certified seed sources and private industries developing and marketing wheat seeds in Nebraska.

Other suggestions on using the Fall Seed Guide to select wheat varieties include:

• Emphasize performance over years and across locations and consistency in performance.
• Emphasize varieties that showed good disease and pest ratings at locations nearest to your farm or at locations with similar growing conditions to yours. Also assess a variety in reference to disease conditions expected in your area.
• Depending on your farm condition and management style, consider potential benefit from stalks and crop aftermath.
• Look for other agronomic characteristics that fit your management style and production objective.

Acknowledgement

Financial support from Nebraska Wheat Board to test wheat varieties submitted by public institutions from Nebraska, Colorado, Kansas, Wyoming, and South Dakota is appreciated. Wheat variety testing and the publication of the seed guide would not have been possible without this support.

Teshome Regassa, State Variety Testing Coordinator
Department of Agronomy and Horticulture