Help For Making Maturity Group Decisions At MidSouth Locations

When I was a soybean researcher at Stoneville, MS, three of the most frequent questions posed to me were:


  • If I plant on date X, what MG should I select varieties from to realize maximum yield potential?

  • If I plant variety Y on date X, when will Stage R1 (beginning bloom) occur so I will know when to plan to start irrigating?

  • If I plant variety Y on date X, when can I expect that variety to be at harvest maturity?


From my personal research, I could answer those questions with relative confidence for the Stoneville area, but could not provide more than an educated guess when the questions came from someone more than about 50 miles north or south of Stoneville.

In the near future, that should change.

Last month, the United Soybean Board approved funding for a three-year regional project entitled “Effect of Planting Date, Latitude, and Environmental Factors on Choice of Maturity Group in Midsouth Soybean Production”.

It is known that differences in varietal performance (plant height, seed yield and quality, susceptibility to diseases and insects, etc.) occur within and across maturity groups (MG’s), across planting dates, and with latitude (north-south location). However, there is no measurement of these differences using a common set of variables across the Midsouth region.

The purpose of the research outlined in the above project is to:

  • Produce data that can be used to predict the effects of latitude on growth, development, and yield of a uniform set of selected varieties from MG’s 3, 4, 5, and 6 when planted from late March through mid-June at several Midsouth latitudes.

  • Measure disease and insect incidence in each planting date at each location, and document the associated costs of controlling these pests at each latitude.


The proposal for this research project was submitted by the Midsouth Soybean Board (MSSB). The MSSB is a group that represents the Qualified State Soybean Boards (QSSB) of Arkansas, Louisiana, Mississippi, and Texas. Each of those QSSB’s makes a financial contribution to support MSSB activities.

In this blog, I prefer to report research findings that will give Mississippi soybean producers new and/or improved knowledge that can be applied immediately to their operation. In this case, it is a pleasure to report potentially forthcoming new knowledge that will be of value to every soybean producer in the Midsouth region. I will keep you posted on results from this research as they become available.

larryheatherly@bellsouth.net