Response of Soybean Plant Types to Planting Patterns1

Abstract

AbstractFour plant types—short determinate (dt1), tall determinate (Dt2), narrow leaflet (ha), and normal—in both ‘Harosoy’ and ‘Clark’ soybean [Glycine max (L.) Merr.] genetic backgrounds were compared in various planting patterns at Urbana, Illinois. The eight lines were seeded in 76‐ and 25‐cm row spacings with seeding rates of 84, 168, and 252 kg/ha in 25‐cm rows and 84 kg/ha in 76‐cm rows.A greater leaf area index was provided earlier in the season when plants were spaced in 25‐cm rows. LAI increased as seeding rate increased. More light penetrated farther into the canopies of the narrow leaflet type than the normal type. Plant height increased with higher seeding rates and narrower row spacings. Stem diameter and number of pods per plant decreased as seeding rates increased. Lodging increased as row spacing decreased and plant population increased. Plants of the short determinate types did not lodge. Row spacing and seeding rate did not statistically affect seed yield. The tall determinate types yielded 4.6% more than the normal types. There was no difference in yield between the short determinate and normal or the narrow leaflet and normal plant types.