REDUCING BELL PEPPER FLOWER ABSCISSION WITH ETHYLENE INHIBITORS IN FIELD EXPERIMENTS.

In previous research, pepper flower abscission has been brought about by ethylene, and prevented under greenhouse conditions by the ethylene action inhibitor silver thiosulfate (STS). Field experiments in 1991 and 1992 compared the abscission response and yield of `Shamrock', `Ssupersweet 860' and `Lady Bell' when treated with foliar sprays of STS (l×l0 -3 M or 5×l0 -3 M), or the ethylene synthesis inhibitor AVG (50 or l00ppm), applied at flowering. Abscission, measured a week after the chemicals were applied, was reduced from 16 to 4% in 1991, and from 16 to 5% in 1992 by the higher STS rate but not affected by AVG. `Ssupersweet' and `Shamrock' averaged 14% abscission during the measurement interval, while `Lady Bell' had 8%. Treatments did not change marketable yields, but the high rate of STS increased total and cull fruit numbers by 35 and 41%, respectively. All cultivars showed similar abscission and yield responses to the treatments.