Screening Pepper Cultivars for Resistance to Flower Abscission: A Comparison of Techniques

Abstract

In one greenhouse and two field experiments, eight or ten pepper (Capsicum annuum L.) cultivars were subjected to low-light stress by use of shade cloth (reducing light by 80%) or to foliar sprays of ethephon at 75 or 150 pi-liter-]. Both low-light stress and ethephon identified `Ace', 'Canape', and. `Belrubi' as less susceptible to flower and flower bud abscission than other cultivars in the first field experiment. In the 2nd year, air mean maxima of 32C caused severe abscission in controls and shaded plants, and complete loss of flowers in those sprayed with ethephon. Abscission of disbudded pedicels was not related to abscission susceptibility of eight cultivars when subjected to shade. While ethephon spray can serve as a satisfactory abscission screening tool under unstressed growing conditions, low-light stress imposed by shading may be used under a wider range of conditions. Chemical name used: 2-chloroethyl phosphoric acid (ethephon).