Disinfestation and vase-life extension of orchids by irradiation

Studies on disinfestation and vase-life extension of orchids by irradiation were conducted to determine whether gamma-radiation can be effectively used to eliminate thrips and prolong the vase life of cut flowers. Cut flowers of Dendrobium Pompadour were subjected to Co-60 irradiation at 0, 50, l00, l50, and 200 krd doses 5 to 6 hours after picking. The flowers were separated into two groups. The first group was used to count the number of thrips. The other group was held at controlled room temperature (200C and 80 percent RH) for 36 hours before being unpacked and placed in water. The results of two experiments illustrated that at 2 days after irradiation at l50 and 200 krad no thrips were found on the flowers, whereas on flowers untreated and those treated at 50 and l00 krad, a higher number of thrips were detected. As far as the vase life is concerned, treated flowers have a shorter life. Irradiation at 0, 50, l00, l05, and 200 krad doses resulted in average vase life of l8.75, l2.l5, l0.85, 8.85, and 6.20 days, respectively, in the first test and l4.60, l0.05, 8.75, 7.35, and 6.85, respectively, in the second test. Increased doses of radiation caused flowers to wilt and drop off within a few days. Further study is being conducted