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

'PS72285' paprika pepper and 'Caysan SPS705' cayenne chilli pepper (Capsicu m annuum L.) were treated with ethephon [(2-chloroethyl) phosphonic acid] w ith the aim of synchronising maturation for once-only machine harvesting. E thephon solutions of 0, 1000, 3000 or 5000 mu L/L were applied once as foli ar applications to pot-grown plants in a shadehouse at the Waite Campus, Ad elaide. The effects of ethephon on red fruit yield, colour intensity, punge ncy, abscission and defoliation were determined. Ethephon did accelerate fr uit maturation of both cultivars by increasing the percentage of red market able fruit for chillies and decreasing the percentage of green paprika frui t. The intensity of extractable red colour in chilli fruit was increased by 16% for 1000 mu L ethephon/L, while pungency improved by 46 and 48% for 10 00 and 3000 mu L ethephon/L respectively. However, red marketable fruit yie lds measured as fresh and dry weight decreased in chillies due to a large n umber of abscised fruit. Paprika quality and yield were unaffected. Ethepho n also induced defoliation and fruit skin damage. Thus, this study found li ttle benefit from using ethephon as a chemical ripening agent.