Ammonium (NH4 +-N) and nitrate-nitrogen (NO3-N) fertilizers were spread 30 kg/10a and 60 kg/10a, respectively, as additional fertilizers in nitrogen fertilization to investigate their effects on spring kimchi cabbage's physiological disorders during cold storage. The initial weight of spring kimchi cabbage after harvesting was 3.80 kg with two-fold NO3-N, whereas it was 3.22 kg with one-fold NO3-N. After 90 days of cold storage, the total loss ratio became lower as the nitrogen fertilizer ratio increased. The pH increased, reducing sugar content decrease during the storage. Black speck occurrence became higher as the nitrogen fertilizer increased. Mid-rib brown stain and soft rot were observed slightly in kimchi cabbage regardless of the nitrogen fertilizer ratio. Two-fold NO3-N fertilization showed a positive effect on increasing weight and reducing kimchi cabbage loss, but it exhibited a negative effect on the black speck. The method and content of nitrogen fertilization of spring kimchi cabbage may be adjusted according to the usage and storage periods.

In this study, an appropriate modified atmosphere packaging (MAP) condition to minimize physiological disorders while lowering weight loss was sought. To reduce weight loss during storage, kimchi cabbages packed with 0, 32, 40, 48 perforated low-density polyethylene (LDPE) films, with a diameter of 14 mm, were stored in pallet units for 90 days at 1-2oC, and their loss rate, physiological disorders, total bacteria count, pH, and solid content were analyzed. It was found that as the number of holes increased, the weight loss ratio increased proportionally. However, the difference between the perforations was relatively small compared with the sample without film packaging. On the other hand, it was also observed that the lower the number of holes was, the lower the incidence of physiological disorder was because the cold air penetrated through the perforated hole while inhibiting physiological effects, releasing heat and carbon dioxide generated by respiration. Considering the weight loss rates and physiological disorders such as black speck and soft rot, the kimchi cabbage packed with 48 perforated films (73.9 cm2) exhibited the most satisfactory condition. Using this storage condition, along with 2-3oC temperature and 91-95% relative humidity inside the pallet, a highly suitable condition for kimchi processing was obtained to secure kimchi cabbage.

Spring kimchi cabbage was stored fresh for 90 days in a commercial cold storage house. It was sanitized by spraying fungicide on the field before harvesting. The plastic boxes of spring kimchi cabbage were put on the pallet, covered with a 40-hole film, then stacked in the cold storage room at once. The room was maintained for 90 days at 0.7oC after cooling gradually at 2 oC/day. After 90 days, the weight loss was 4.73% and the total trimming loss was 8.26%. The weight loss was 8.08% and the net trimming loss was 3.26% after 90-day storage with partial stack cooling at 2.7oC covered with a 56-hole film. The quality of spring kimchi cabbage after 90-day storage was fresh without physiological disorders.

Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.

Biological control has been tried for integrated pest management. It is often comparable, safe, and environment-friendly, making itself an alternative for chemical agents. Filamentous microorganisms, i.e., fungi and streptomystes, produce many kinds of useful metabolites, and some of them have been developed as a biocontrol agent. However, they still have a long way because of the concern of manufacturing cost. Therefore, process development was intensively studied to meet cost-effectiveness. Operating conditions of bioreactor, e.g., agitation and aeration, had an effect on biological and physiological responses such as mycelial morphology, oxygen and nutrient transfer. Understanding relationship between operating parameters and microbial responses in terms of growth, substrate and oxygen consumption, and production yield was critical for process development. This study dedicated to build strategies for mass production of biological control agent using aerobic filamentous microorganisms.

Fusarium head blight (FHB) is a major disease problem on wheat and barley around the world. F. graminearum produces trichothecenes mycotoxins such as nivalenol (NIV), deoxynivalenol (DON), and zearalenone (ZEA). The objectives of this study were to survey the natural occurrence of FHB and mycotoxins of 32 Korean wheat cultivars grown in 2011-2012 seasons at the National institute of crop science, Iksan, Korea. There was great deal of rainfall and high humidity during flowering time in May 2011. FHB incidence was counted by Fusarium infected spikes per square meter. The samples of 32 wheat cultivar were collected. The grain and flour samples were to analysis for DON and NIV by gas chromatography and ZEA by high performance liquid chromatography. The result showed that the average of FHB incidence(%) per square meter in 2011 and 2012 were 4.2%, 0.5% respectively. There were significant cultivar differences for FHB incidence ranged from 0% to 24% in 2011. All of 32 wheat cultivars contained 9-2088 ng/g for NIV and ten wheat cultivars contained 5.7-8.5 ng/g for ZEA. In addition, DON concentration of Tapdong, Shinmichal1, and Hanbaek were 217, 35 and 683 ng/g respectively. However, the grain and flour sample harvested in 2012 showed that lower FHB incidence and NIV concentration. These results showed that the 32 wheat cultivars harvested in 2011 were heavily contaminated with Fusarium mycotoxins (NIV, DON, ZEA).

Stem rust of wheat caused by Puccinia graminis f. sp. Tritici is historically one of the most important diseases of crops worldwide. The objective of this study was to screen the growth habits and yield of wheat accessions in Korea winter condition. We collected ninety stem rust resistant germplasms from USDA-Grain and planted for the characteristics of growth and yield in 2013. We measured the growth characteristics such as the plant type, leaf color, heading date, stem length, spike length, awn length, number of spikelet, number of tiller, and 1,000 kernel weight (g). Early maturity is most important wheat breeding target in double cropping system such as Korea. Heading dates of ninety cultivars ranged from May 17 to June 7. The Keumkang control cultivar headed on May 23. Heading dates of seventeen accessions had as early as Keumkang control (May 23). The numbers of semi-erect and intermediate type for growth habit were 45 and 33 respectively. The 1000 kernel weights were also measured. Mean 1000 kernel weights ranged from 16.7g (Webster) to 41.8g (123 A1C2). The average of stem length was 100.2cm and Keumkang was 58.4cm. These results showed that A4849-60P-7P-1P (Chile), MG 31492 (Ethiopia), 1338.F.6.C.3.B (Kenya), 1203 A1C2 (Kenya), and II-90-20/3-1R-1M- 3R (Mexico) were best lines for agronomic characteristic such as early heading date and grain yield

Fusarium head blight (FHB), primarily caused by Fusarium graminearum is a major disease problem on wheat and barley around the world. The objectives of this study were to evaluate for FHB resistance under greenhouse and filed condition in 2012 and 2013. We screened for Type I resistance in the field using spray inoculation and for Type II resistance in the greenhouse using single floret inoculation. Sumai 3 and Ning7840 were used the FHB resistant check. Five hundred and twelve lines were evaluated for resistance to initial infection (type I) and to spread of symptoms within spike (type II). The inoculum was F. graminearum (GZ3639) prepared at a concentration of 1 X 105 macroconidai/ml with Tween 20. The field screening plots were inoculated twice and mist-irrigation was applied to facilitate FHB development. FHB severity was assessed visually 21 days and determined as the percentage of symptomatic spikelets from the total of all spikelets observed in 20 spikes. Both in the greenhouse and field test, we could observe five categories of FHB severity: resistant (R: 0-20%), moderately resistant (MR: 21-40%), moderate (M: 41-60%), moderately susceptible (MS: 61-80%), and susceptible (S: 81-100%). The results showed that seventy seven lines showed the R and MR category on FHB severity. In addition, nine lines showed similar FHB severity compared to Sumai 3 (13.3%).

Fusarium head blight (FHB), caused by Fusarium graminearum is a major disease problem on wheat and barley in Korea. The objectives of this study were to evaluation of korean wheat cultivars for Type I and Type II resistance to FHB. We screened for Type II resistance in the greenhouse using single floret inoculation and for Type I resistance in the field using spray inoculation. Sumai 3 was used the FHB resistant check. Thirty-two korean wheat cultivars were evaluated for resistance to spread of symptoms within spike. The 2013 field screening with wheat cultivar was located in Kimjae-si Joeonbuk Korea. All plots were inoculated twice. Mist-irrigation was applied to facilitate FHB development. FHB severity was assessed visually 21 days after inoculation on 20 arbitrarily selected spikes per plot. FHB severity was determined as the percentage of symptomatic spikelets from the total of all spikelets. For FHB resistance, the average of FHB severity of Type I exhibited ranging from 21.9% to 77.2% and FHB severity of Type II ranging from 20.8% to 100%. Namhae, Milseong, Geuru, Joen, Anbaek and Sukang were the moderately resistant cultivars while Gobun, Alchan, Dajoong, Eunpa, Shinmichal1, Eunpa and Uri were the most susceptible cultivars for Type II resistance.

Fusarium head blight (FHB), caused by Fusarium graminearum is a major disease problem on wheat and barley in Korea and around the world. We screened for Type II resistance in the greenhouse using single floret inoculation and for Type I resistance in the field using spray inoculation. Sumai 3 was used the FHB resistant check. Three hundred and seventy lines were evaluated for resistance to spread of symptoms within spike (type II). The 2012 field screening with 300 wheat lines was located in Kimjae-si Joeonbuk Korea. All plots were inoculated twice. The first inoculation was applied at anthesis for wheat. The second inoculation was applied three days after the initial inoculation (dai) for each plot. The inoculum was F. graminearum (GZ3639) prepared at a concentration of 100,000 macroconidai/ml with Tween 20 added as a wetting agent. Mist-irrigation was applied from the first inoculation on May 7 till June 7 to facilitate FHB development. FHB severity was assessed visually 21 days after inoculation on 20 arbitrarily selected spikes per plot. FHB severity was determined as the percentage of symptomatic spikelets from the total of all spikelets observed in these 20 spikes. Based on the field test, we could observe four categories of FHB severity: resistant (R: 0-20%), moderately resistant (MR: 21-40%), moderately susceptible (MS: 41-60%), and susceptible (S: 61-100%). The results showed that forty four lines showed the resistant category on FHB severity between 2.7% and 19.8%. In addition, ten lines showed similar FHB severity compared to Sumai 3 (9.9%).