Fickle weather and growing conditions can make producing soybeans an unpredictable business. To maximize yield, growers need to be proactive when it comes to planting, scouting and harvesting soybeans. In the planning stage, choosing the right agronomic packages and maturity groups can help minimize the risk of damage from weather, pests and diseases, and help growers manage their harvest timelines.
Iowa State University Extension agronomists consider yield, disease resistance and maturity group the top characteristics when it comes to variety selection. “Planting earlier-maturing soybean varieties can help protect against some early-season pests and diseases,” says Randy Kool, agronomic service representative for Syngenta. “The earlier maturing varieties offer a different timeline for plant development during the growing season than fuller maturities.”
Manage pest pressures
Soybean plant development can impact the effect of various diseases and pests throughout the growing season. For example, planting an earlier-maturity bean may help prevent certain diseases, such as sclerotinia stem rot, or white mold, from developing. The disease is not common every year, but ISU researchers recommend growers assess fields annually since crops may be at risk for the disease to develop. For a number of Iowa soybean growers, white mold was an issue in 2014.
“Planting a range of maturities serves to help manage different pests properly,” says Kool. “An earlier-maturing variety typically will have a smaller, more compact canopy, which allows for more air circulation and sunlight. This makes it more difficult for diseases, such as white mold, to become established and reproduce.”
Mid- and full-season varieties can also offer an additional yield pickup. Planting these varieties can help maximize yield in years with more optimal growing conditions. ISU agronomists, however, caution growers in Iowa against planting full-season maturities past June, as plants may be more susceptible to frost damage.
Select the right maturity
Maturity group ratings accommodate varying growing environments. To spread out the harvest window, Kool recommends planting three types of maturities: early, midseason and full-season beans. “An earlier maturity can be used to begin harvest, a midseason variety for the middle of the harvest window, and a full-season variety for the last portion of the harvest,” he says. “This helps reduce harvest loss due to soybeans becoming too dry, shattering from the combine and yield loss due to shrink.”
To determine which maturity groups work best in Iowa, Kool divides the state into thirds: northern, central and southern Iowa. Relative maturity groups between 1.7 and 2.7 are better adapted for the northern part of the state. Growers in the central portion should consider planting soybeans in maturity groups 2.0 through 3.0. Since growers in southern Iowa see a longer growing season, Kool suggests planting a 2.5 relative maturity variety for early-season plants running through 3.5 maturity for full-season varieties.
Research shows maximum yield potential is genetically determined. Therefore, once the maturity group is identified, it is important for growers to select varieties with different genetic backgrounds that are adapted to their local environment.
Selecting high-yielding varieties with the right agronomic packages will help soybean growers come out on top at harvest. According to Kool, “A good portfolio provides strengths against local pests and diseases that we all need help with from time to time. Our NK Soybean portfolio provides elite proprietary genetics for growers to spread their risk from a genetic standpoint. Over and above that, the NK Soybean portfolio covers a wide range of maturities for any geography.”
Understanding the various growing environments will provide growers with a proactive approach to selecting the right maturity group for their area, he adds. Growers should consult their local seed dealer or retailer for recommendations on what will work best on their specific fields.
This article published in the April, 2015 edition of WALLACES FARMER.
All rights reserved. Copyright Farm Progress Cos. 2015.