풀무치[Locusta migratoria (메뚜기목: 메뚜기과)]를 사육할 때 보조먹이로서 전지분유, 밀기울, 옥수수잎 가루, 설탕을 주성분으로 한 혼합 인공사료를 제조하였다. 갓부화 약충에 인공사료만을 제공하여 성충 사망 때까지 사육하였을 때, 다음 세대 집단을 얻지 못했다. 인공사료를 매일 제공하면서 옥수수 잎을 하루걸러 제공하였을 때도 다음 세대 개체를 얻지 못했다. 그러나 인공사료와 옥수수 잎을 하루걸러 번갈아 제공하였을 때는 이후 4세대까지 사육이 가능하였다. 성충의 생식력도 옥수수 잎과 인공사료를 매일 같이 제공한 경우보다, 두 먹이를 하루걸러 번갈아 제공 한 경우가 더 높았다. 이상의 결과로 본 연구에서 개발된 인공사료를 주먹이인 식물체의 보조먹이로 삼아 일정기간 풀무치 집단 유지에 이용할 수 있을 것으로 추정되었다.

본 연구는 부패미생물의 종류와 차이를 알아보기 위해 유기농산물과 일반농산물(깻잎, 양배추, 상추)을 구입하여 4oC에 14일 저장한 후 일반목적배지를 사용하여 미생물을 분리 및 16S rRNA sequencing방법을 이용하여 동정하였다. 유기농산물 깻잎, 양배추, 상추의 총균수는 5-7 log10 CFU/g 수준이었고, 일반농산물의 총균수는 5-8 log10 CFU/ g 수준이었다. 유기농산물보다는 일반농산물이 총균수를 더 많이 내재하고 있으나 유의적인 차이는 나타나지 않았 다(p > 0.05). 유기농산물 깻잎에서 발견된 주요 균은 Microbacterium sp.이었으며, 일반농산물 깻잎에서 발견된 주요 균은 Stenotrophomonas maltophilia이었다. 또한, 유기농산물에서 부패를 일으킬 수 있는 균인 Klebsiella pneumonia 가 발견되었으며, 일반농산물보다 유기농산물에서 발견된 균의 종류가 더 많은 것을 확인할 수 있었다. 이에 본 연구 결과는 부패미생물에 대한 이해를 높이고 농산물의 신선도 및 유통기한을 늘리기 위한 새로운 살균소독제 및 부패 억제제를 개발하는데 좋은 기초자료로 사용될 수 있을 것으로 사료된다.

This study assessed the efficacy of aqueous chlorine dioxide (CIO2) and commercial chlorine sanitizer in terms of its ability to eliminate Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli 0157:H7 on radish sprouts (Raphanus sativus L.). Radish sprouts were inoculated with a cocktail containing one each of three strains of three different foodbome pathogens, then treated with distilled water (control) or chemical sanitizers (100 ppm commercial chlorine, and 50, 100, 200 ppm CIO2) for 1, 5, and 10 min at room temperature (22士2℃). Populations of S.Typhimurium, E. coli 0157:H7 and L. monocytogenes were counted at 4.64, 6.05, and 4.29 log CFU/g, respectively, after inoculation. Treatment with water did not significantly reduce the levels of any of the three foodbome pathogens. The levels of all three pathogens were reduced by treatment with chemical sanitizers; however, the observed 1evels of reduction of E. coli 0157:H7 and L. monocytogenes were not significant as compared with the controls. The levels of the three pathogens were reduced most profoundly when treated for 10 min with 200 ppm of CIO2, and the reduction levels of S. Typhimurium, E. coli 0157:H7, and L. monocytogenes were 1.17, l.63, and 0.9610g CFU/g, respectively. When chemically injured cells were investigated using SPRAB for E. coli 0157:H7 and by selective overlay methods for S. Typhimurium and L. monocytogenes, respectively, it was noted that commercial chlorine sanitizer generated more numbers of Í넌red pathogens than did CIO2. These data indicate that CIO2 treatment may prove useful in reducing the numbers of pathogenic bacteria in radish sprouts.

A total of 15 different corn hybrids, Kwangpyeongok, Gangdaok, Yanganok, Singwangok, Jangdaok, Cheonganok, Cheongdaok, Andaok, Dapyeongok, Pyeongkangok, Pyeonganok, Daanok, Sunwon 184, Gangilok, and P3394 was used to investigate the growth and yield depending on the sowing date. The sowing dates were April 5, June 25, and July 5 and each experiments was performed in triplicste. The growth of Gangdaok was the highest. However, although the growth of Kwangpyeongok, was lower thanthar of Gangdaok, its stem height to ear height ratio was lower than that of Gangdaok, thus , Kwangpyeongok may be more suitable for stable cultivation. Both growth and yield of Daanok were low, regardless of planting date, but yield and ear shape of Pyeongkangok and Dapyeongok were for fresh corn. Growth and yield of the 15 different corn hybrids varied depending on the planting date, However, the growth degree days (GDD) was the most important factor governing the maturity of corn. More than 1500°C of GDD was sufficient to harvest mature corn hybrids in the central region of Korea. Besides yield and growth, other characteristics, such as sweetness and taste of the hybrids, should be investigated further the selection of the best corn hybrid.

A long-term field experiment under different fertilization treatments had been conducted to explore the effects of rice yield and soil chemical properties from 1978 to 2008 in Suwon, Korea. The paddy was applied eight fertilization treatments which were F0 (no fertilizer), PK (phosphorous and potassium), NK (nitrogen and potassium), NP (nitrogen and phosphorous), NPK (nitrogen, phosphorus and potassium), NPKC (NPK with compost), NPKS (NPK with straw) and NPKL (NPK with lime). Results of 31 years experiment showed that yield index (the ratio of yield in each treatment to NPK) was the lowest in F0 (0.52) and the highest in NPKC (1.18). Yield index was gradually increased in NPKC but decreased in F0 and NK. The yield index of PK, NP, NPKS and NPKL were not changed long-term treatment. Soil acidity of NPKL showed the highest with pH 7.9, and that of other treatments ranged from pH 6.3 to 6.8. Available phosphorous content of soil was increased in all plots by long-term fertilization, was the highest in PK and NPKC. Soil organic matter was higher in NPKC (1.8%) and NPKS (1.8%) than other treatments (1.3~1.4%) in the early experiment, but that was remarkably increased in only NPKC (2.5%) according to annual long-term application. Thus we suggest that annual compost application with optimum NPK could make stable and sustainable rice production.