Effects of ethephon on fruit yield, colour and pungency of cayenne and paprika peppers

Abstract

Summary. ‘PS72285’ paprika pepper and ‘Caysan SPS705’ cayenne chilli pepper (Capsicum annuum L.) were treated with ethephon [(2-chloroethyl) phosphonic acid] with the aim of synchronising maturation for once-only machine harvesting. Ethephon solutions of 0, 1000, 3000 or 5000 µL/L were applied once as foliar applications to pot-grown plants in a shadehouse at the Waite Campus, Adelaide. The effects of ethephon on red fruit yield, colour intensity, pungency, abscission and defoliation were determined. Ethephon did accelerate fruit maturation of both cultivars by increasing the percentage of red marketable fruit for chillies and decreasing the percentage of green paprika fruit. The intensity of extractable red colour in chilli fruit was increased by 16% for 1000 µL ethephon/L, while pungency improved by 46 and 48% for 1000 and 3000 µL ethephon/L respectively. However, red marketable fruit yields measured as fresh and dry weight decreased in chillies due to a large number of abscised fruit. Paprika quality and yield were unaffected. Ethephon also induced defoliation and fruit skin damage. Thus, this study found little benefit from using ethephon as a chemical ripening agent.