Use of 1-methylcyclopropene for the control of Botrytis cinerea on cut flowers

Cut flowers are marketed for their ornamental characteristics making post-harvest flower life an important determinant of crop value. Botrytis cinerea is one of the most significant post-harvest fungal pathogens causing losses in ornamental plants. Disease caused by this fungus seems to be enhanced by the presence of a ethylene hormone, that both the plant and the fungus are known to synthesize. The aim of the experiment was to determine if 1-meth-ylcyclopropene (1-MCP), an ethylene antagonist, could be used to reduce B. cinereadamage to cut flowers. Six cultivars of four ornamental species: Dianthus caryophyllus‘Idra di Muraglia’, Rosa ×hybrida ‘White Dew’ and ‘Ritz’, Ranunculus asiaticus‘Saigon’ and ‘Green’, and Cyclamen persicumline ‘Halios Bianco Puro Compatto’ were given three concentrations of 1-MCP (0.38 μl L-1, 1.14 μL L-1, and 3.62 μL L-1) for 24 hours. Subsequently, 10 petals per cultivar were treated with a B. cinereaconidial suspension (5×10 3conidia cm-2) and stored in air-tight vases. To evaluate B. cinereadevelopment an arbitrary damage scale (1–7) was used. A high concentration of 1-MCP significantly reduced B. cinerea damage on D. caryophyllus ‘Idra di Muraglia’ and C. persicum ‘Halios White Pure Compact’ petals. In carnation, 1-MCP treatment slowed B. cinerea infection; its thre-shold level was reached three days after that of the control. In cyclamen, treated petals and control petals remained aesthetically good until day 53 and day 28 respectively. At low concentrations, 1-MCP slowed grey mould on R. × hybrida ‘Ritz’ for up to three days beyond the control. On the two buttercup cultivars ‘Green’ and ‘Saigon’, 1-MCP treatments were not effective. In conclusion, 1-MCP limited pathogen development; its effect depended on the species and the 1-MCP concentration. Further investigations will be performed to improve methods to reduce B. cinerea development on the petals of cut flowers.