Evaluation of Yield and Economic Loss Due to Twin Row Planter Problems for Soybean Production in the Mid-South.

Twin row planting has gained popularity amongst soybean producers in Mississippi and throughout much of the Mid-South.  Twin row planting has been shown to improve seed yield through rapid canopy closure.   Novel technology often gives rise to potential equipment malfunction and/or misuse that could reduce seed yield.   Producer decisions in the event of a planting/planter problem can be challenging when one or both of the twin rows are absent.  The economic impact of the problem may vary by soybean maturity and soil type due to differences in plant development.  The purpose of this research is to determine the agronomic effects associated with multiple potential twin row planter problems on two distinct soil types across a variety of maturity groups commonly found in Mississippi.  Canopy closure of each problem was monitored throughout the growing season.  Stand counts and plant heights were measured before and after harvest.  Seed yield was determined with a combine and seed mass was determined after harvest.  Results show that across both soil types, absence of both twin rows result in greater yield loss compared to when one row, or two separated rows, were missing.  Yield was not reduced when only one twin row was missing, however is reduced when one whole row is missing.  Additionally, loss of yield was greater at the heavy clay site due to restricted growth.  It would only be economical to consider replanting with absence of both twin rows, especially on clay soil.