Figure 1. Wheat variety test plots.

Soon the 2013 UNL Wheat Seed Guide will be out, detailing the results of the 2013 UNL wheat variety trials. This article addresses how to use the guide and various other information resources to select the best variety for your production system and operation.

Variety selection is both an art and a science. It requires judgment by the producer at several levels so specific local and farm conditions and management considerations can be addressed.

Selecting the best performing winter wheat varieties is one of the most important farm management decisions a grower can make. This decision is not easy. The best decision requires knowing the performance of a range of wheat cultivars that could fit specific growing conditions. It also requires a fair forecast of the growing season or, at least, a belief that it will be a good season for the selected variety to perform to yield potential.

Wheat Trial Data Available

The UNL Variety Testing Program provides up-to-date information on performance of public and private winter wheat varieties across the state. Producers can mitigate the effects of a poor season by applying the right management that enables the variety to perform at or near yield potential. Good management and appropriate inputs should be part of the conversation when selecting a variety. Good management can make an average variety perform better, while bad management can make a superior variety a second-rate performer. When selecting a variety, the will to provide the right management at the right time is key.

The seed guide includes a table listing soil type and management factors such as plot history, crop rotation, previous crop, residue management, tillage, and other factors. The information is relevant to evaluate varietal performance in terms of yield, grain quality, and disease reaction and to judge replication of the observed performance in the intended field. Producers are encouraged to relate the test site information to their farm to assess whether they're likely to see the same results under their farming conditions and management. Another way to evaluate this is to talk with a producer who planted the variety in a test plot, particularly during field days and plot tours.

2013 Factors to be Considered in Your Comparison

As is the case for all seasons, the past season had its own idiosyncrasies. Planting was done, particularly in the west and west central, into unusually dry soil. Due to such dry conditions at planting, there were sites with no emergence before freezing. However, the poor stand problem observed at planting due to dry conditions for most locations was compensated for by aggressive tillering and grain development from the favorable condition created by good moisture in the spring. Some plots had water stress at grain fill while others had considerable hail damage. The seed guide includes a distribution chart of monthly rainfall and distribution to aid in considering performance at specific sites. Disease and pest incidence was unusually high during the past season. (See CropWatch articles throughout May and June.)

Table 1. Winter wheat varieties recommended by region for dryland and irrigated conditions in Nebraska.  (Links to larger version.)

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Tips for Evaluating Variety Trial Data

It is highly recommended producers look at multi-site and multi-year performance data in selecting a variety. This can keep you from missing a good variety that happened to be at a poor site or under poor management for a season. Tables in the Seed Guide report performance across sites and across years. Choosing multiple varieties that bring unique and complementary traits to the management system is expected to minimize risk.

Based on available information, it is customary to recommend a set of varieties for a region based on yield and other merits. Varieties recommended statewide by region under dryland and irrigated conditions are shown in Table 1. Most wheat variety testing regions have more than one testing site. Yield means reported across locations in the Fall Seed Guide and at individual sites at the variety testing website can be evaluated side by side. Information posted in complementary UNL websites such as the Wheat Virtual Tour and the Winter Wheat Variety Selection Tool are based on  information in the Fall Seed Guide and also can be used.

The seed guide and variety testing website in CropWatch include information on key characteristics of each variety, including yield, seed size, test weight, and grain protein. Important additional information such as relative values for maturity, winter hardiness, straw strength, coleoptiles length, disease and insect resistance, and relative ranking in performance for yield, bushel weight, and protein are also in the Fall Seed Guide. The information on the ranking by yield, protein, and bushel weight shows the relative ranking of varietal performance for the variable stated across locations where the variety was tested. The ranking can be used to judge how consistently the variety is likely to perform, given the stated variety variable.

Other consideration in selecting wheat varieties:

• Emphasize varieties that showed good disease and pest rating at locations near your farm or at locations with similar growing conditions to yours as well as for disease conditions expected in your location.
• Look for other agronomic characteristics that fit your management style and production.

Teshome Regassa
Agronomist, Research Assistant Professor and State Variety Testing Coordinator