The Effect of Ethephon on Onion Seedstalk Height and Seed Production Characteristics1

Abstract

(2-Chloroethyl)phosphonic acid (ethephon) applied to onions ( Allium cepa L. cv. Excel) at 5% seedstalk emergence at 2500, 5000, or 10,000 ppm reduced seedstalk height from 94 to 68, 62, and 54 cm, respectively. Lodging at seed harvest was reduced from 53% to 10%. The 2500 and 5000 ppm treatments had no effects on seed yield, but the 10,000 ppm treatment tended to lower it. Seed weight and seed germination were not affected by treatment.