Ethephon and 2,4-D Do Not Improve Periderm Color and May Decrease Yield in Red-skinned `Norland' Potato

Abstract

Ethephon and 2,4-D were foliarly applied to red-skinned `Norland' potatoes (Solarium tuberosum L.) to determine if periderm color could be enhanced at harvest and throughout storage. Base rates of 250 and 185 ml·liter–1 for ethephon and 2,4-D, respectively, were applied at the onset of tuberization (tubers ≥ 2.5 cm in diameter). Base or double-rate foliar applications of either ethephon or 2,4-D resulted in significant U.S. No. 1 yield reductions and did not affect periderm color intensity at harvest or throughout storage sufficiently to warrant their use. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon), (2,4 -dichlorophenoxy) acetic acid (2,4-D).