For the purpose of acquiring microbial agents that can be utilized to billogically control the major airborne disease to apple trees, such as canker(Valsa ceratosperma), the effective microorgaisms were isolated, tested for antagonistic activity to the pathogen causing major disease to apple trees and identifed. Screening of more than 3, 000 species of microorganisms collected in nature for them antagonistic action to the pathogen, Valsa ceratosperma causing disease to apple tree resulted in selection of effective species. Out of the 11 species, one species designated as CAP141 demonstrated outstanding activity. The bacterial strain, CAP141 exerted antagonistic efficiency of 65% on Valsa ceratosperma. The CAP141 was identified as a bacterial strain to Bacillus subtilis based on morphology, culture conditions, and physio-biochemical characteristics.

Cultivation of peach by organic farming and cooperative form of work was attempted. The compost was made from egg shells and bread residues(bakery residues), falling leaves, and weeds. The cooperative teams of work were farmers, students and members of citizens' movement. The responses of participants for composting, though it's laboriousness and dirtiness, were favorable with feeling of doing good for social services. 20 chickens were raised in the peach orchard as one of the mixed farming. The pH and Ca content of ripened compost were 7.7 and 1.57 %, respectively. Controlling Aphids(plant louse)by ladybug was observed vividly. The size and sugar concentration were comparable to standard values even though rainy season and the number of damaged fruits were less than half(40%).

This experiment was carried out to investigate the growth response of 3 grasses to seed coating with chitosan solution and the attempt was made to estimate adequate seed coating concentrations of chitosan solution in each grass for the growth to be stimulated. Three species used in this experiment were orchardgrass, tall fescue and reed canarygrass. Six different seed coating concentrations of chitosan solution were applied as 0%(control), 0.01%, 0.05%, 0.1% and 1.0%, respectively. the results were obtained as follows; 1. Dry weight of tiller(WT), leaf area(LA), dry weight of leaf(LW), dry weight of stem(SW), dry weight of shoot(SHW), biological yield(BY) and C/F ratio were significantly different between species. 2. Number of tillers per plant(NT), dry weight of tiller(WT), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW), biological yield(BY) and T/R ration were significantly different between seed coating concentrations of chitosan solution. 3. The adequate seed coating concentrations of chitosan solution for the growth stimulating effect were different between species. The highest values of yield components and dry weight of plant parts were obtained at 1% in orchardgrass and tall fescue, and 0.05% in reed canarygrass, respectively. 4. Growth stimulating effect of seed coating in each species were different. The highest values were obtained in leaf area(LA), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW) and dry weight of biological yield(BY) in orchardgrass. The values of dry weight of stem(SW) and C/F ration were highest in reed canarygrass. 5. An increase in number of tillers per plant(NT), dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in dry weight of shoot(SHW). Among the aboved increasing factors, the dry weight of leaf(LW) was a main factor for the increase in dry weight of shoot(SHW). 6. An increase in dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in biological yield(BY). Both the dry weight of leaf(LW) and dry weight of root(RW) were main factors for the increase in biological yield(BY).

This study aims to find out the devices to minimize the amount of nitrate ingested from kimchi, the main way of vegetable intake for Koreans, and the basic data to deliver to calculate the total daily intake for Korean, investigating the year-round changes of nitrate content in vegetables for Kimche raw material, and changes of nitrate content by salting of chinese cabbage, and stewed kimchi through the use of different cooking methods. The results obtained were summarized as follow: over between 205-6655mg/kg f.w. in chinese cabbage, 480-3970mg/kg f.w. in chinese radish, 157-5820mg/kg f.w. in lettuce and 29-520mg/kg f.w. in cucumber respectively. Therefore it was strongly adviced to introduce the nitrate limit value of vegetables in Korea if the nitrate content in Kimchi should be reduced to meet the nitrate ADI(Acceptable Daily Intake, 219mg60kg b.w) of FAO.WHO, because the nitrate content in Kimchi reflects the nitrate content in vegetables. In order to keep the low nitrate content in Kimchi. it was adviced to remove the outer leaf which contains 2-3 times higher nitrate content compare to the inner leaf at the time of preparation, i.e. chinese cabbage, before the soaking treatment in salt solution for Kimchi making process. The dehydration by soaking treatment in salt solution occurred at 0.9%~4.7% in leaf midrib and more than 13%~24% in leaf blade. The nitrate content after soaking in salt solution was increased 107%~123% compared with before soaking, increasing rates of nitrate content in the outer and inner leaf midrib were higher than those in leaf blade. The increase of nitrate content in salt solution after soaking due to the dehydration of chinese cabbage by soaking treatment. The Kimchi stew(Kimchi JJige) was processed with and without animal oil, but the amount of nitrate in kimchi stew did not decrease both treatments, but it increased after the processing since the water in Kimchi stew has got low by boiling.

The results of application of the organic manure obtained from livestocks fed with BLCS in the Tomato under structure were as follow. The No. of Fruit weight, Fruit width, Fruit length and Sugar content of Tomato in the Dung of fowl(BLCS) were high in the other treatment, second was cattle dropping(BLCS), third was Pig dropping(BLCS). The contents of Total N, P2O5, K2O, CaO, and MgO in the Tomato fruit of the cattle dropping(BLCS), the Pig dropping(BLCS), and the Dung of fowl(BLCS) were high than animal dropping plots.

Cultural conditions for mass production of the antagonistic bacteria, Bacillus subtills CAP141 against pathogens causing major airborne diseases to apple trees, effects of temperature, pH, carbon and nitrogen source in the culture broth were investigated. The bacterial growth was most vigorous when the temperature and pH of the culture broth was 30~35$^{\circ}$C and 7, respectively. As for carbon source, dextrose was best followed in order by dextrose(monosaccharide) > sucrose(disaccharide) $\geq$ saccharose (market disaccharides) > starch (polysaccharieds). Among different sugars, bacterial growth was favored by in the order of brown, black and white supars, indicating that the bacterial growth might be promoted by the minor elements presented as impurities in the less purified sugars. As for nitrogen source, organic forms were better to bacterial growth than inorganic forms, that is polypeptone was best followed in order by soy sauce, soybeen milk and inorganic nitrogens. Differences in bacterial growth among different forms of inorganic nitrogen were negligible.

The aim of this experiment was to investigate the effect of applying times of cattle slurry on dry matter yield of Orchardgrass, when cattle slurry applied at rates of 30m3(average mineral nitrogen fertilizer equivalent to 120kg) per ㏊ in different dressing times, such as S1(1st and 2nd growth), S2(1st and 3rd growth), S3(1st and 4th growth), S4(2nd and 3rd growth), S5(2nd and 4th growth) and S6(application for 3rd and 4th growth). The results were as follows. 1. The average annual yields of dry matter were produced 6.36~7.42 ton per ㏊ in 1995~1997 when cattle slurry applied at rates of 30m3(average mineral nitrogen fertilizer equivalent to 120kg) per ㏊ in different dressing times, especially these tendency were shown higher annual dry matter in S4 plot9application for 2nd and 3rd growth). Those were higher 2.48~3.54 tons or 1.22~2.28 tons per ㏊ than the yields from non-fertilizing or phosphrous and potassium fertilizing. 2. Relative yields of annual dry matter in cattle slurry application plots were 164(S2 plot)~191(S4 plot)% in comparing with non-fertilizing plot. 3. Dry matter yields according to cutting frequency were highest at the 2nd cut(1.50 ton) and were in the order 3rd cut(0.95 ton)>4th cut(0.75 ton)>1st cut(0.69 ton/㏊). Also, those of cattle slurry application plot per ㏊ were in the order 2nd cut(2.02~2.73 tons)>3rd cut(1.56~2.08 tons)>4th cut(1.07~1.68 tons)>1st cut(1.11~1.45 tons/㏊). 4. Relative yields of annual dry matter in cattle slurry application plots were 164~219, 161~210, 143~212 and 135~182% at the 3rd, 1st, 4th and 2nd cut, respectively in comparing with non-fertilizing plot. 5. The efficiencies of nitrogen on dry matter yield(kg DM/kg N) were 18.1, 21.3 and 34.5kg DM/kg N when cattle slurry applied to Orchardgrass at rates of 30m3 (average mineral fertilizer equivalent to 120 kg) per ㏊ in 1993, 1994 and 1995, respectively, especially these tendency were shown higher efficiencies in S4 plot(application for 2nd 3rd growth). On the other hand, those of the same level fertilization of mineral nitrogen were 43.8, 19.2 and 13.4 kg DM/kg N in 1993, 1994 and 1995, respectively.

This experiment was carried out to examine the effect of various functional materials such as bioceramic podwers, crushed shells and elvanites supplemented to the each substrate on the seedlings growth of cucumber, watermelon and tomato. The seedlings were grown in pots filled with substrates of bioceramic podwers, crushed shell and elvanites. The growth of cucumber seedlings in terms of plant height, stem diameter, leaf width, leaf area, plant fresh and dry weight was promoted by adding the bioceramic. powder (1 to 2g/kg), crushed shells (20 to 80g/kg) or elvanites (20 to 80g/kg). Watermelon seedlings in terms of plant height, number of leaves and leaf area were greater than those of the control by adding bioceramics (1 to 2g/kg). Plant height was also promoted by the adding of bioceramic power from 16 days after treatment. But leaf area was increased from 8 days after treatment, while stem diameter was not affected. Watermelon seedlings were also influenced by adding curshed shells (20 to 80g/kg) and elvanites (20 to 40g/kg) into each substrate. The growth of characteristics of tomato seedlings were promoted by adding 1 to 3g/kg of bioceramics, 10 to 80g/kg of crushed shell or 20 to 40g/kg of elvanites, respectively. Especially, root growth was greatly influenced by bioceramic powder, whereas the shoot growth(leaves and stem) was stimulated by crushed shells and elvanites suppemented into substrate.

For the environmental protection, it is more desirable to use compost rather than chemical fertilizer. So in this paper, the effects of compost upon the rice quality were investigated with Hwajin Rice as the test variety. The rice quality and physicochemical characteristics were examined and the resrlts are as follows. As to the rice quality, the rate of polished rice was high in the non-fertilizer and the compost plot, the degree of transparency was high in the order of the traditional, the compost+urea, the compost and the non-fertilizer plot. The amylose content (one of the physicochemical characteristies of the rice), the rate of Mg/K, and the adhesivity and the cohesion power (charateristies of texturogram which show the density of boiled rice) were also high in the compost polt. Among the amylogram characteristics, the gelatinization temperature was lowest in the compost plot ; the lowest and the highest degree of viscosity and the break down were also inclined to be higher in the compost plot than in the traditional plot. After the soil test, the components of available phosphorus, organic matters, calcium, magnesium, potassinm and silicate increased in the soil as compared with those before test.

This experiment was carried out to examine the effect of various functional materials such as bioceramic podwers, crushed shells and elvanites supplemented to the each substrate on the seedlings growth of rices. The rice seedlings were grown in pots filled with substrates supplemented with bioceramic podwers, crushed shells and elvanites. The growth of rice seedlings in terms of plant height, stem diameter, root length and leaf width, plant fresh and dry weight was promoted by adding the bioceramic powders (2 to 3g/kg), crushed shells (10g/kg) or elvanites (20 to 40g/kg). Plant height was also promoted by the adding of bioceramic powder from 16 days after treatment, whereas crushed shells and elvanites from 10 days after treatment. Especially, root growth was greatly influenced by bioceramic powder, whereas the shoot growth(leaves and stem) was stimulated by the crushed shells and elvanites supplemented into each substrate. In the field, plant growth in terms of plant height, leaf length and leaf width were also influenced by crushed shells and elvanites at 74 days after treatment. The growth of rices in terms of tiller number, spikelets, panicles and spikelets/panicle was incresed by adding the crushed shells and elvanites from 100 to 200g per m2.

Recently, the importance of management and cultivation of grasses has been increased in Korea. Among these cultural practices, the appropriate control of diseases is considered more important than other cultivation techniques such as fertilization and irrigation. The damages of brown patch and large patch caused by Rhizoctonia spp. and Pythium blight caused by Pythium spp. are serious in the major cultivation area of turfgrass in Korea. Since these diseases are difficult to control by agrochemicals, the damages are very serious if these are occured. The periodic spray of agrochemicals, to protect and control these diseases could make some problems of toxicity and environmental pollution as well as rising of non-target diseases. Therefore, the biological methods to control diseases have been required to decrease problems resulted from overuse of agrochemicals, to conserve natural ecosystem, and to control effectively diseases of grasses in the long period. The number of studies about biological control using antagonistic microorganisms have been increased for last half century. However, the application of biological control method has been very limited. In this study, thirteen isolates of R. cerealis, 8 isolates of R. solani and 3 isolates of Phthyn spp. have been isolated from diseased turfgrass in golf course and grass-culture area that have patch and wilting symptoms of zoysia grass and creeping bentgrass. Isolation frequency of R. cerealis and R. solani was high in especially zoysiagrass, while Pythym spp. was isolated from bent grass at low frequency but showed high pathogenicity. Totally, 205 isolates of soil microorganisms were isolated in this study as primary antagonistic microorganism by Herr's triple agar layer plate and dual culture method using rhizosphere of grasses, soil of crop field as the source of antagonistic microorganisms. Among the 205 isolates, 23 isolates were actinomycetes and 182 isolates were bacteria. All of the actinomycetes were isolated by Herr's method. Antagonistic effect of primary isolated microorganisms was tested for in vitro mycelial growth inhibition against pathogenic fungi isolated from grasses and for inhibition of disease occurrence in 24 well tissue culture plate and pot experiment. Then, four isolated of bacteria which are BG23, BG74, BG136 and BG171 were selected as antagonistic microorganisms against soil-born pathogenic fungi of bentgrass.

Azospirillum sp., photosynthetic bacteria(Rhodopseudomonas sp.) and Pseudomonas sp. were separated and screened from soil and soilless culture, and identificated. The antifungal activities against root-infected pathogens and plant growth promoting effects of the cultured solution of the starins(5.0$\times$105 cells/$m\ell$) in the peatmoss compost on the early growth of cucumber and tomato seedling were investigated. Azospirillum sp. and Pseudomonas sp. showed a antifungal activities against Fusarium sp., Pythium sp. and Rhizoctonia sp in thed ranges of 51.0% to 72.0% on potato dextrose agar medium, however photosynthetic bacteria had not antifungal activities. When cultured solution of Azospirillum sp., photosynthetic bacterial and Pseudomonas sp. were bacterialized by mixing with peatmoss compost, early growth of cucumber and tomato in terms of plant height, number of leaves, leaf area, root length, fresh anf dry weight of leaf, stem and root were promoted, especially photosynthetic bacteria had a the best plant growth promting activities.