Economics of Soybean Maturity Groups’ Yield Response to Insecticides Seed Treatments with Early Planting 1Normie Buehring, 2Angus Catchot, 3Don Cook, and 3Jeff Gore 1NMREC Center; 2Entomology and Plant Pathology Dept, MSU; 3Delta Research and Extension Center

Objective Evaluate the effect of insecticide seed treatment on: Variety Maturity Group (lll, lV, and V) and planting dates on growth and yield. Returns above seed treatment cost. B. Determine optimum planting dates for soybean variety maturity groups.

Locations: Verona, Starkville, and Stoneville Maturity Groups Varieties: MGIII (AG3906); Early MGIV (AG4403); Late MGIV (Pioneer 94B73); Early MGV (DK5068); and Late MGV (DP5634). Planting dates: Early April, Early May, and Early June. Seed treatments: Apron (CK) and Apron + Cruiser.

a a b b b bc bc bc cd d d de de de A + C = 28.3 a A = 26.5 b 1.8 e

a a b bc cde bcd cde def efg defg gh fgh hi i bcde def efg defg gh fgh hi A + C = 50.3 a A = 46.0 b 4.3 i

12D 16D 22D

a a ab ab ab bc c c c c d d d de e A + C = 64.0 a A = 61.9 b 2.1

14D 18D 22D

Plant Height at Maturity Yield } b 2.7 a

Acknowledgement This research was supported in part by the Mississippi Soybean Promotion Board.