One of the main factors that affects soybean yield is planting date. Previous studies indicate that early planting dates can result in higher soybean yields by avoiding late-summer drought and reducing the incidence of disease and insect infestations.1 However, delays in planting are common when double-cropping and in years with excessive rainfall.
Selecting the best maturity group (MG) for a given planting date and location can help farmers maximize yield potential. Growers often have questions about the possibility of reducing the length of the production season by planting earlier soybean varieties for the Midsouth region.
Additionally, Midsouth soybean growers are interested in determining the best combination of row configuration and soybean product to maximize soybean yield potential.
A demonstration trial was conducted at the Bayer Learning Center at Scott, Mississippi to evaluate the yield response of Asgrow® brand soybean products of different MGs to planting date and row configuration.
RESEARCH SITE DETAILS
|Location||Scott, MS||Planting Date||4/24/19, 5/23/19|
|Soil Type||Silt Loam||Harvest Date||As mature; 96-145 days after planting|
Seven Asgrow soybean brands (AG01X9, AG19X8, AG25X8, AG30X9, AG35X9, AG46X6, and AG51X8), ranging in maturity from MG 00 to MG 5, were planted in twin rows (7.5 inches apart on 38-inch beds) and single row (38-inch) beds on two planting dates, April 24 and May 23, 2019.
Plot size was 0.5 acre and standard agronomic practices for the area were implemented with irrigation provided as needed.
A desiccant to aid in harvest was applied when soybean seed pods were brown in color. Plots were then harvested 5 to 7 days later. A range of harvest dates was used based upon when soybean products reached maturity.
UNDERSTANDING THE RESULTS
Soybean yield was relatively high in both planting dates with the earlier planting date of April 24th showing the highest yield potential in this study (Figure 1).
In 2019, the twin row production system for these seven Asgrow® brands showed a similar advantage in yield potential across most soybean products and planting dates with an average advantage of 2.5 bu/acre compared to the single row production system (Figure 3).
Current production system norms in the Midsouth consist of MG 4 and 5 soybean products planted on dates ranging from late March to early July with products planted in mid-April to mid-May having the highest yield potential. This demonstration study agrees with current commercial experience; Asgrow® AG46X6 brand (MG 4.6) was the highest yielding soybean product in 2019 in this study (Figures 1 and 2).
Many of the tested soybean products demonstrated acceptable yield potential, showing some potential commercial viability for earlier products in our southern system. Planting earlier MG soybean products could allow reductions in time to harvest but should be done with an understanding of the risk/reward involved.
Growers should evaluate each field, farm, and case individually before planting soybean varieties greatly different from products that previously showed very high yield potential.
In this demonstration, twin rows generally produced slightly higher yields than single rows; however, both planting configurations demonstrated acceptable yield potential.
1Heatherly, LG. March 15, 2018. How early can (should) soybeans be planted? Mississippi Soybean Promotion Board. http://mssoy.org