This study was conducted to reduce contamination ratio of oyster mushroom bottle cultivation. The optimalconditions of substrate sterilization for reducing of contamination ratio were at 121oC for 90min. In addition, UV-C irradiation isgood for lower contamination ratio to continue over 6 hours at cooling and inoculation room after sterilization. Thecontamination ratio and density of microorganisms of substrate were showed 0% after sterilization at 121oC for 90min.Trichoderma sp., main pathogen of mushrooms, was detected from substrate after sterilized during 2 or 4 hours at 101oC and 105oC,respectively. The amount of electricity used was the lowest at 121oC for 90min than that of other sterilization conditions. The UV-Cirradiation treatment was used UV-C lamp(40 watts) in the inoculation room(56m3). The density of bacteria did not detected after UV-C irradiation for 6 hours. And the death ratio of bacteria and Trichoderma sp. was 99.9% after UV-C irradiation for 6 hours. However,in the same UV-C irradiation time, the death ration of Cladosporium sp. was 90.9%. Therefore, the death ratio of fungi was lower thanthat of bacteria at the same UV-C irradiation treatment.

This experiment was conducted to prevent the contamination of parasite egg on vegetables for supporting safety production of leafy vegetables. After the chinese cabbages and soil samples were collected at 5 cities of Gyeonggido during 2007-2008, the existence of parasite egg was surveyed. All collected samples had no parasite egg, so the chinese cabbages produced in Gyeonggi area were assumed parasite egg-free. To examine the characteristics of parasite eggs, the pig roundworms, Ascaris suum, were collected from the intestine of infected pig and the parasite eggs were collected from the uterus of A. suum. The eggs of A. suum developed to embryonated eggs, which can infect humans, in 20℃-30℃, but not 15℃ and 35℃, when cultured at different temperatures. The eggs developed to embryonated eggs after drying for 0-24h when cultured after different drying times. Effect of soakage different salt solution and times showed that the eggs developed to embryonated eggs after soakage at 0-25% salt solution for 0-24h. For eliminating the parasite eggs attached leafy vegetables, it was efficient to soak at salt solution for 5 minutes and washing 5 times with water.

Western flower thrips, Frankliniella occidentalis(Perg.), is one of the major pests of lettuce, Lactuca sativa. To develop the economic thresholds for western flower thrips on lettuce, the thrips was inoculated into two types of lettuce, green deeply lobed leaf lettuce which was harvested every week and red frilled & crinkled leaf lettuce which was harvested one time, with a density of 0, 1, 3, 7, 10 thrips per one lettuce after planting 1 week and 3 weeks at the plastic house in 2006, and 0, 1, 3, 5, 7 thrips per one lettuce after planting 1 week in 2007. There was close correlation between the initial thrips density and the marketable quantity of lettuce : y = -155.36x + 3564.7, r2=0.9724('06), y = -167.82x + 3474.5, r2=0.8897('07) in the green deeply lobed leaf lettuce inoculated the thrips after planting 1 week, y = -109.65x + 3549.1, r2=0.9384('06) in the green deeply lobed leaf lettuce inoculated the thrips after planting 3 weeks, y = -197.09x + 3334.9, r2=0.9707('06), y = -244.08x + 3425.9, r2=0.8914('07) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 1 week, y = -101.07x + 3457.6, r2=0.7334('06) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 3 weeks. The economic threshold for western flower thrips on lettuce was ranged 0.20～0.30 thrips per one lettuce in the blue type lettuce and 0.14～0.33 thrips per one lettuce in the red type lettuce.