Priming Sweet Corn Seed to Improve Emergence Under Cool Conditions

from primed seed was significantly different than emergence from unprimed seed on each day but 16 and 21 (P = 0.01, arcsin transformation). Corn inbreds planted when soil is 10C and lower are often injured by cold water imbibitional stress (Cohn and Obendorf, 1978). Bodsworth and Bewley (1981) found that polyethylene glycol (PEG) 6000 promoted seed germination of two field corn cultivars when germinated at 10C. The objective of the current study was to evaluate PEG 8000 for improving emergence of two sh2 sweet corn hybrids. Six seeds of sweet corn sh2 hybrids (’Crisp ‘N Sweet’ and ‘How Sweet It Is’; Crookham Seed Co.) were placed in 9-cm-diameter petri dishes containing 15 ml of PEG 8000 absorbed into two sheets of Whatman #1 filter paper. Seeds were in excellent contact with a thin layer of PEG on the surface of saturated filter paper. Concentrations used were 100,200, and 300 g PEG/liter distilled water (-0.16, -0.56, -1.14 mPa, respectively) (Michel, 1983). Seeds were primed at 15C for either 4, 3, 2, or 1 days, such that priming was completed for all seeds on the same day. Control seeds received no treatment. Excess PEG was rinsed off with distilled water. Control and treated seeds were planted immediately after completion of the 4-day priming treatment. Six seeds of each cultivar were placed on the surface of unsterilized potting mixture of 1 vermiculite :1 sand :1 pedite :1 silt loam soil (by volume) in 0.8liter round pots and covered to a depth of 2.5 cm. There were two pots per treatment for each cultivar. Pots were covered with plastic wrap to prevent moisture loss and placed in a growth chamber at 10C for 12