Victoria L. Tenbrink

Postharvest heat treatment of red ginger flowers as a possible alternative to chemical insecticidal dip

Abstract A postharvest treatment in hot water at 49 °C for 12 to 15 min eliminated > 95% of ants, banana aphids and mealybugs infesting red ginger flowers, Alpinia purpurata (Vieill.) K. Schum. In a ‘systems-approach’ to quarantine security, preharvest chlorpyrifos applications combined with either a postharvest hot-water immersion at 49 °C for 12 min or 5-min insecticidal dip in a combination of fluvalinate 2.0 flowable (F) and insecticidal soap eliminated all pests, including aphids, mealybugs, thrips, soft scales, and ants. Phytotoxicity resulting from hot-water treatment was characterized by bract necrosis and shortened vase life. Flowers were more susceptible to heat injury if harvested during periods of high rainfall. Conditioning flowers in hot air at 39 °C for 2 h before hot-water treatment eliminated phytotoxicity.

Insecticidal dips for disinfesting commercial tropical cut flowers and foliage

Abstract Insecticidal dips were evaluated as a postharvest treatment to eliminate insects from tropical cut flowers and foliage before shipment. Among candidate insecticides, a combination dip for at least 5 min of an insecticidal soap composed of potassium salts of fatty acids (0.98% active ingredient) with fluvalinate (0.023% active ingredient) was the most effective against pest insects, but rinsing flowers with water immediately after dipping reduced efficacy. No phytotoxicity was observed when this dip was used at double concentration for most cut flowers and foliages, but damage was obvious for cycads, orchid flowers and some anthurium cultivars.

Postharvest heat treatment of red ginger flowers as a possible alternative to chemical insecticidal dip: [Postharvest. Biol. Technol. 7 (1996) 137–144]

Abstract A postharvest treatment in hot water at 49 °C for 12 to 15 min eliminated > 95% of ants, banana aphids and mealybugs infesting red ginger flowers, Alpinia purpurata (Vieill.) K. Schum. In a ‘systems-approach’ to quarantine security, preharvest chlorpyrifos applications combined with either a postharvest hot-water immersion at 49 °C for 12 min or 5-min insecticidal dip in a combination of fluvalinate 2.0 flowable (F) and insecticidal soap eliminated all pests, including aphids, mealybugs, thrips, soft scales, and ants. Phytotoxicity resulting from hot-water treatment was characterized by bract necrosis and shortened vase life. Flowers were more susceptible to heat injury if harvested during periods of high rainfall. Conditioning flowers in hot air at 39 °C for 2 h before hot-water treatment eliminated phytotoxicity.