Soybean Seed Yield Response to Plant Density by Yield Environment in North America

CARCIOCHI, WALTER D.; SCHWALBERT, RAI; ANDRADE, FERNANDO H.; CORASSA, GEOMAR M.; CARTER, PAUL; GASPAR, ADAM P.; SCHMIDT, JOHN; CIAMPITTI, IGNACIO A.

AGRONOMY JOURNAL

AMER SOC AGRONOMY

Año: 2019 vol. 111 p. 1 - 10

0002-1962

Inconsistent soybean [Glycine max (L.) Merr.] seed yieldresponse to plant density has been previously reported. Moreover,recent economic and productive circumstances have causedinterest in within-field variation of the agronomic optimal plantdensity (AOPD) for soybean. Thus, the objectives of this studywere to: (i) determine the AOPD by yield environments (YE)and (ii) study variations in yield components (seed number andweight) related to the changes in seed yield response to plantdensity for soybean in North America. During 2013 and 2014,a total of 78 yield-to-plant density responses were evaluated indifferent regions of the United States and Canada. A soybeandatabase evaluating multiple seeding rates ranging from 170,000to 670,000 seeds ha?1 was collected, including final number ofplants, seed yield, and its components (seed number and weight).The data was classified in YEs: low (LYE, 4.3 Mg ha?1). Themain outcomes were: (i) AOPD increased by 24% from HYE toLYE, (ii) per-plant yield increased due to a decrease in plant density:HYE > MYE > LYE, and (iii) per-plant yield was mainlydriven by seed number across plant densities within a YE, butboth yield components influenced per-plant yield across YEs.This study presents the first attempt to investigate the seed yield to-plant density relationship via the understanding of plantestablishment and yield components and by exploring the influenceof weather variables defining soybean YEs.