Silver thiosulphate can considerably reduce leaf and fruit abscission caused by ethylene in Capsicum annuum ‘Janne’

Abstract

SummaryThe pot plant Capsicum annuum ‘Janne’ is very sensitive to ethylene. Experiments were therefore conducted to see whether silver thiosulphate (STS) could prevent leaf and fruit abscission caused by ethylene and darkness. A phytotoxicological experiment with plants sprayed at different developmental stages with 0.05, 0.15, 0.45, 1.35 or 4.05 mM STS showed no damage and no developmental after-effects. The effect of STS on abscission was also investigated in a stress experiment, which consisted of two main treatments: darkness for 72 h at 20°C, without applied ethylene, and darkness of 72 h at 20°C with an ethylene concentration of 1.0 μl l–1. The STS treatments were given as sprays of 0.45 or 4.05 mM 1,11, or 21 d before the start of the darkness and ethylene stress treatments. The ethylene concentration of 1.0 μl I–1 on non-sprayed plants caused abscission of leaves, and of the green and maroon fruits, but the red fruits were unaffected. Treatment with 4.05 mM STS, 1 or 11 d before ethylene exposure, considerably reduced the ethylene induced abscission, with little effect of treatment 21 d before ethylene exposure. However, compared with the greenhouse environment control, spraying 1 d before ethylene exposure in darkness and high relative humidity caused leaf damage that appeared only after ethylene exposure.