Frost and Cold Temperature Damage to Small Soybeans

The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.” – John F. Kennedy

  • Farmers aim to achieve the highest potential yield at the best cost to achieve maximum profitability.
  • To help maximize profits, some farmers may consider cutting back on or completely cutting out some inputs altogether. These decisions should be calculated and thought through completely.
  • Setting realistic yield goals based on calculated decisions and planning ahead, results in maximum profit potential.

Figure 1. Side dressing nitrogen

As a farmer, the goal is to optimize profitability through the maximization of yield potential and cost control; however, this is often easier said, then done. This is particularly true when inputs costs are rising and the crop price is declining or expected to be lower at harvest.

Setting Yield Goals1,2

Realistic yield goals can help the producer achieve the greatest difference between the value of the crop and the cost of producing the crop. Recognize that exceptionally good years are the exception and not the rule. Disregard yields from years where weather related disasters resulted in very poor yields. Keep records for each field as an individual unit. Set your goals 5 to 10 percent above your average yield of the past five years. Utilize field mapping technology to aid in goal setting.

There are a few different approaches to use when determining your yield goals:

  • Using previous year’s production. This is a good tactic when a field has been used for several years, particularly when field maps are available for previous years.
  • Maximum yield approach. This approach is based only on inputs and management skills. Little, if any, consideration is given to soil potential and variations. This approach can be risky as it doesn’t consider the costs of inputs needed to reach that goal or past yields achieved.
  • Soil productivity approach. This approach focuses on soil productivity potential, available water, subsoil moisture, and management skills.

Consider Your Inputs3

Inputs include labor, crop protection products like herbicide and fungicides, equipment, seed, and energy. Most farm inputs are purchased, making production costs susceptible to non-farm economic conditions.

When input prices are low, farmers should attempt to maximize production to reduce the per unit cost of production, with the goal of covering variable costs and as much of the fixed costs as possible. Production inputs are usually known allowing farmers to plan ahead. Knowing in advance can allow farmers to purchase in advance at reduced prices in areas like the cost of land, fertilizer, and seed.

Several Land-Grant Universities have developed spreadsheets that can assist in developing crop budgets for several crops. For example Iowa State University has this site for 2021 budgets https://www.extension.iastate. edu/agdm/crops/html/a1-20.html, North Carolina State University has this site for 2021 budgets, https://cals., and South Dakota State University has this site for 2021 budgets,

To help maximize profit potential, some farmers may consider cutting back on or completely cutting out some inputs altogether. These decisions should be calculated, thought through completely, and be based on past experiences, not emotional. For example, use extreme caution when cutting back on inputs like fertilizers. Farmers need to ensure that the farm fertility is properly maintained to provide good yields and root structures that support healthy stands and reduce erosion. Cutting back too much on fertilizer inputs not only lessens
the chance of having a good yield year in the coming season, but also in future years. Weed management is becoming a larger driver for input costs as weed resistance to herbicides becoming more common. Developing a weed management plan and sticking to it for the entire farm may result in higher input costs, but it may also be in the best interest for long-term profitability. Crop rotation may also help reduce input costs by reducing some fertilizer and farm chemical costs as well as seed costs. Taking the time to set realistic yield goals based on calculated decisions and planning ahead can result in the maximum return on investment and profitably.


1 Miller, A.G. 2000. Establishing realistic yield goals. Agronomy Pm-1268. University of Iowa Extension.
2 Shober, A. and Taylor, R. 2015. Estimating yield goal for crops. University of Delaware Extension.
3 2015. It’s not just about costs per acre, even in tight times. Purdue University Extension.

Legal Statements

ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.

Bayer and Bayer Cross are registered trademarks of Bayer Group. All other trademarks are the property of their respective owners. ©2021 Bayer Group. All rights reserved. 1017_S7

Frost and Cold Temperature Damage to Small Soybeans

Frost and Cold Temperature Damage to Small Soybeans

  • Soybeans respond differently to frost compared to corn because the growing point is exposed to weather as soon as the cotyledons emerge.
  • Understanding the effects of weather conditions on soybean at different growth stages can help determine the best management options.

Soybeans vs. Corn

Soybeans are more susceptible than corn to frost and cold temperatures. The growing point for corn remains below ground until corn reaches about V5 (5 visible leaf collars) growth stage. Comparatively, the growing point for soybean is above ground and exposed to the elements as soon as the cotyledons emerge.

If the main growing point (also called the apical meristem) is damaged, soybeans have a greater ability to recover than corn. Soybean plants can produce new growth auxiliary buds found at each node. When this regrowth occurs from the node where the cotyledons or unifoliate leaves were attached, it has been referred to as psi syndrome due to the shape.

Will the Soybean Plant Make It?

Frost damage to soybean plants can occur when temperatures range between 28 to 32 °F. Temperatures of 29 to 30 °F may be tolerated for short periods of time when soybeans are in the VE (emergence) to VC (unrolled unifoliate leaves) growth stages. Several days of cool temperatures can harden a plant, and when this occurs, temperatures of 28 °F may be tolerated. Complete death (buds, stems, and leaves) is not expected until temperatures remain at 28 °F for an extended period of time for sensitive plants. Soybeans in the VC stage are slightly more frost tolerant compared to soybeans in the V1(first-trifoliate) and V2 (second- trifoliate) growth stages. Soybeans with emerged trifoliate leaves (V1 and V2 growth stages) become more susceptible to temperatures below 32 °F for any extended time.

Patience is needed to determine if an individual soybean plant is likely to survive a frost. It helps to wait a few days before evaluating the potential for new growth at the auxiliary buds. In Figure 1, the plant on the left has been injured by frost for 24 hours and may have tissue death below the cotyledonary node. The plant on the right was injured by frost, but only down to the area above the cotyledonary node, allowing for regrowth from the auxiliary buds at that node. The growth from those auxiliary buds will be similar to that of the original plant had it not been damaged by frost. The odds of the injured plant on the right producing a respectable yield potential are very good.

Figure 1. Examples of frost damage to soybeans. Plants with severe frost damage that begins below the cotyledonary bud (left) may have tissue death. If regrowth at the cotyledonary node is seen (right), plants may contribute to yield.

Will the Soybean Plant Make It?

Replanting a field of frost-damaged soybeans demands more consideration since soybeans are more susceptible than corn to frost and cold temperatures. However, soybeans can tolerate stand reductions fairly well. Often, if a soybean stand is evenly distributed, replanting is not recommended unless populations are less than 100,000 plants per acre. As the season progresses, vigilant scouting should continue for seedling blights and environmental damage in soybean fields, especially those damaged by frost.

There are many resources available addressing soybean early growth and survival. Additional information on evaluating soybean early growth and survival can be found in the video blog developed by Extension Specialist Shawn Conley at soybean-emergence-and-germination-common-issues/.

Sources: Berglund, D.R. 2004. Spring frost damage to crops could be a problem. News. North Dakota State University. 120601023004

For additional agronomic information, please contact your local seed representative. Developed in partnership with Technology Development & Agronomy by Monsanto.
Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible. ©2017 Monsanto Company.120601023004. 051215SEK