Soybeans: Variety Selection

Excerpt from Agronomy Guide for Field Crops (Chapter 4)

Order OMAFRA Publication 811: Agronomy Guide for Field Crops

Table of Contents

1. Variety Selection
   • Maturity and CHUs
   • Hilum Colour
   • Choosing Superior Varieties
   • Identity-Preserved (IP) Varieties
   • Biotechnology
2. Updates on Soybeans: Variety Selection
3. Related links...

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Variety Selection

There are over 200 soybean varieties, and their turnover in the marketplace is relatively quick. Aside from maturity and yield, variety selection should also be based on resistance or tolerance to disease, standability and soybean cyst nematode resistance.

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Maturity and CHUs

Select a variety that corresponds to the heat unit rating for your farm (see Figure 3-1, Crop Heat Units Available for Corn Production. Selecting full-season varieties will make maximum use of the growing season and offer the opportunity to maximize yield. However, when growing specialty soybeans such as the white hilum types, selecting shorter-season varieties will help ensure quality at harvest.

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Hilum Colour

The hilum is the point at which the soybean seed attaches to the pod. Varieties differ in hilum colour and can be yellow (Y), imperfect yellow (IY), grey (GR), buff (BF), brown (BR), black (BL) or imperfect black (IBL). Yellow hilum soybeans are generally the preferred type for the export market. Hilum discolouration may occur on the imperfect yellow (IY) varieties. Affected beans may not be acceptable for export markets.

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Choosing Superior Varieties

In addition to maturity rating, other factors of importance are yield potential, standability and insect and disease resistance. In selecting superior varieties, three main sources of information exist:

1. performance trial data
2. on-farm strip trial data
3. company information on characteristics of a variety

The Ontario Oil and Protein Seed Crop Committee conducts performance trials each year at various locations across the province. Results are published each fall in the Ontario Soybean Variety Trials brochure. This brochure is also available on the Internet at www.soybean.on.ca. These trials are valuable for comparing the yield potential of varieties. The trials also provide ratings for maturity, plant height and lodging. In Southwestern Ontario at locations with clay soil types, varieties are evaluated for resistance to Phytophthora root rot. Varieties with Phytophthora root rot-resistance are recommended on heavier soils. In fields with soybean cyst nematodes (SCN), varieties with SCN resistance should be included regularly in the rotation (see the section Soybean Cyst Nematode).

On-farm strip trial information is useful in determining the adaptability of a variety over a wide range of conditions. Trial result summaries are provided by the Ontario Soil & Crop Improvement Association at their Web site (http://www.ontariosoilcrop.org). The performance trials and summaries of on-farm trials, where sufficient comparisons exist, are valuable tools for variety selection.

Seed companies will provide detailed information on growth characteristics of varieties to aid in selection. When evaluating variety performance, take into account that variety trials conducted under conventional tillage have proven to be a reliable indicator of a variety's performance under no-till conditions.

Select a variety with reduced lodging potential on soils with high residual nitrogen levels or on medium- to light-textured soils. If the soybeans are intended for on-farm livestock feed, a variety with a high protein index should be chosen.

Individual varieties may perform differently depending on growing conditions. Grow more than one variety to reduce the risk of total crop failure. Plant the majority of the acreage to proven varieties while testing new varieties on a smaller scale.

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Identity-Preserved (IP) Varieties

Identity preservation is the segregation of a variety from planting through to delivery to an end user. It is not a new concept but has existed in a number of markets, including seed production and the production of food-grade soybeans. The introduction of genetically modified organisms (GMO) crop varieties has resulted in consumer demand for identity-preserved, non-GMO soybeans. The market offers various levels of premiums and contracts to the grower. The premiums offered for producing IP varieties need to be weighed against their increased costs, time and management. Limit the acreage planted to a size that can be harvested in a timely fashion. Performance information for some specialty-trait varieties may not be available. Data for these varieties may only be available from the company selling the seed and/or agreeing to take delivery of the crop after harvest. The agronomic qualities of an IP variety, such as yield, disease resistance and maturity should be evaluated to determine whether or not the premium offered upon sale is adequate. Performance trials of a number of food-grade soybeans are conducted by the Ontario Oil and Protein Seed Crop Committee. This information is available on the Ontario Soybean Growers Web site at http://www.soybean.on.ca. For crop insurance purposes, Agricorp provides a yield adjustment factor for a number of specialty soybeans.

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Biotechnology

Varieties carrying special traits, such as resistance to certain herbicides, are now available in Ontario. These may have value for growers trying to address specific weed problems. They can also be useful in certain tillage systems. These varieties may not be accepted in all soybean markets.

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Updates on Soybeans: Variety Selection

• Ontario Soybean Variety Trials

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Related links...

• .Soybeans

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