Current Status of Bio-Fertilizers and Bio-Pesticides Development, Farmer's Acceptance and Their Utilization in Korea

Hyeong-Jin Jee
Organic Farming Division
National Institute of Agricultural Science and Technology
Rural Development Administration, Suwon 441-707, Korea, 2009-04-07

Key words:     bio-fertilizers, bio-pesticides, environment-friendly agriculture, microbial agents, EXTN-1, egg yolk and cooking oil (EYCO)

Introduction

Intensive agriculture is inevitable in Korea because of the limited arable land and the high population. Hence, agricultural researches and technologies aimed to increase high quality yields until the 1980s. However, the intensive and high-input agriculture generated various negative side effects on the agro-ecosystem and the environment such as pollution and soil degradation. Improvements in living standards during the last decades are associated with an ever-increasing demand for a year-round and diverse supply of food in the country. It was recently reported that Korean consumers are concerned most about food safety for their health, as well as their lifestyle's sustainability.

Since mid-1990s, environment-friendly agriculture has been a new trend to ensure sustainable agriculture and sound environment in Korea. The agricultural policy of the government (Ministry of Agriculture and Forestry, www.maf.go.kr) has driven the `Environment-friendly Agriculture Supporting Law' since 1997. The policy aims to sustain productivity and conserve environmental quality of soil and water, reduce pollution and other environmentally harmful effects, recycle organic resources, and produce safe foods. Substantially, the MAF aimed to reduce 40% of chemical fertilizers and pesticides produced in 2003 until 2013. Inputs of fertilizers are decreasing slowly from 382 kg in 2000 to 257 kg in 2006. However, the use of pesticides to control various pests and weeds has not been reduced much yet, applying ca. 12.5 kg/ha/year. Nevertheless, it is expected that the input of chemical fertilizers and pesticides will decrease because the certified environment-friendly agricultural acreage has rapidly increased from 2,000 ha in 2000 to 74,995 ha in 2006.

Bio-Fertilizers

To reduce input of chemical fertilizers yet sustain productivity and maintain the agro-ecosystem, bio-fertilizers have become an ideal substitute for fertilization and conditioning of soil in Korean. At present a total of 138 companies are registered as bio-fertilizer manufacturers and hundreds of commercial products comprise ca. $30 million in the agricultural material market. The most commonly used microbial agents are Bacillus spp. Rhizobium spp., Pseudomonas spp., Bradyrhizobium sp., and Azospirrilum sp. (Table 1). The purposes of the bio-fertilizers are soil fertilization and conditioning, and increment in plant growth and health. Various research projects to develop bio-fertilizers and bio-bed soils have been actively pursued by using plant growth promotion rhizobacteria (PGPR), phosphate solubilization microbes, nitrogen fixation microbes, etc..

Extn-1

Among the commercial bio-fertilizers, EXTN-1 developed by the author's research group is the most widely accepted and dependable bio-fertilizer in Korea. EXTN-1 identified as Bacillus vallismortis is a PGPR and an induced systemic resistance (ISR) agent which originated from pepper roots. Soil drenching or seed priming of EXTN-1 stimulated seed germination and growth of about 20 crops without any harmful effects. Furthermore, it showed a broad controlling spectrum to various viral, bacterial, and fungal plant diseases such as CMV, TMV, PVY, and bacterial wilt, anthracnose, rice blast and Fusarium wilt. As a rhizobacterium, population of EXTN-1 increased or stabilized on lettuce roots in hydroponics up to 3-4 weeks after treatment. In the case of cucumber, soil drenching after seed coating showed best plant growth promotion and disease protection in soils as well as in hydroponics.

EXTN-1 consistently promoted growth and quality of lettuce grown during cool season and inhibited bacterial wilt on tomato caused by Ralstonia solanacearum for 4 weeks after treatment. In hydroponics, yield, fruit color, and quality of paprika were improved. In the field, Fusarium wilt of pepper was also effectively suppressed by seed treatment or drenching. For mass production and commercialization, the EXTN-1 powder with a concentration of 1011 cfu per gram was developed. EXTN-1 increased H2O2 in the early stage and induced the expression of resistance genes, PR-1a, HMGR, and PAL. Pre-treatment of EXTN-1 reduced germination and appressorium formation of conidia of Colletotrichum orbiculare on the cucumber leaf (Table 2, Table 3, Table 4, Table 5).

Bio-Pesticides

A total of 23 bio-pesticides are registered in Korea. Among them, 12 are fungicides and the rest are insecticides. The microbial agents include Paenibacillus polymyxa, Bacillus subtilis, Bacillus amyloliquifacians, Paecilomyes fumosoroseus, Streptomyces goshikiensis,  Bacillus thuringiensis var. kurstaki, Bacillus thuringiensis subsp. Aizawai, etc. (Table 6). Target diseases of the bio-fungicides are powdery mildew, gray mold, Pythium and Phytophthora blight, Rhizoctonia patch, and sheath blight. Nine out of the 11 bio-insecticides are Bacillus thringiensis products for the control of various moths attacking vegetables like Chinese cabbage (Table 7). The bio-insecticides formulated with Beauveria bassiana and Paecilomyces fumosoroseus targeted mite and white fly which are troublesome pests in greenhouse cultivation. In spite of their many advantages, bio-pesticides occupy only 2.8% share in the pesticide market comprising $35 million in Korea. However, it is expected that the bio-pesticide market will steadily increase to reach $80 million until the year 2010.

Egg Yolk and Cooking Oil (Eyco) Mixture

Besides bio-fertilizers and bio-pesticides, egg yolk and cooking oil (EYCO) mixture developed by the author is widely adopted by Korean farmers for the control of various pests and increase in plant health. The EYCO is simply made at home using cooking oil, egg yolk, and motor-mixer. Cooking oils showed direct or indirect effect in controlling plant pathogens and insects, and the egg yolk was used as a natural emulsifier and bio-fertilizer. Among various cooking oils, sunflower and rape seed oil (canola) at 0.3-0.5% emulsified with 0.1% egg yolk was the most effective showing over 95% control value of powdery mildew in cucumber and lettuce in a greenhouse. To emulsify the cooking oil with egg yolk effectively, the mixture should be vigorously homogenized for more than five minutes using a high-speed motor-mixer (Table 8, Table 9, Table 10, Table 11, Table 12, Tabale 13, Fig. 1).

When the EYCO was applied, the lettuce seedling stand increased for more than 70% and showed 89.6% to 96.3% control value of powdery mildew that was comparable to a fungicide, Azoxystrobin. Moreover, lettuce yield increased about two times compared to the conventional cultivation. In organic Chinese cabbage production, incidence of downy mildew and Alternaria leaf spot in farms where the EYCO and Bt (Bacillus thringiensis) mixture was applied at 7-day intervals was lower than 1% in two other farms. The degree of insect damage in the farms was negligible (0.3-0.5%). The other two farms that did not apply the technology showed severe damages caused by diseases and insect pests. EYCO and neem mixture effectively controlled trips on lettuce showing 82.2% control value.

Fungal mycelia and conidia were severely distorted or shrunken when sprayed with EYCO. Microbial population on the treated cucumber leaf decreased significantly over a period of seven (7) days. Consequently, it was assumed that the EYCO acts directly against fungal pathogens rather than induces disease resistance on the plant.

Farmer's Acceptance and Utilization

The EYCO can be applied to all kinds of crops to protect various diseases and insect pests. However, it shows relatively high protective effects but low curative effects. Nevertheless, it is widely adopted by Korean farmers because of its simple preparation at home, cheaper price, which is about 1/4 of the price of chemical pesticide, and safety for organic and environment-friendly agriculture. In many field trials, the EYCO proved highly effective in controlling powdery mildews and small insects such as mites. However, application of the EYCO alone could not achieve sufficient control effects on thrips, bigger insects such as moths, and harsh pathogens such as Colletotrichum.

In that case, various fungicidal or insecticidal substances allowed for organic farming are mixed with EYCO to increase effectiveness. Substances allowed for organic agriculture in combination with EYCO are bio-pesticides such as B.t., neem oil (azadirachtin), extracts of plant materials such as hot pepper seed or gingko leaf, sulfur, and copper hydroxide. For example, on control of thrips in lettuce, the mixture of EYCO and 20 ppm of azadirachtin or hot-pepper seed extract increased control value to 66.3-82%, while EYCO alone has less than 40% control value. Depending on the target disease and insect, farmers need to select the appropriate additive to EYCO.

References

• Codex. 2004. Guidelines for the production, processing, labeling and marketing of organically produced foods.
• Eyhorn F., Heeb M., and Weidmann G. 2002. IFOAM training manual for organic agriculture in the tropics. Theory, transparencies, didactic approach. IFOAM. Germany.
• Foguelman Dina. 2003. Pests and diseases in organic management: A Latin American perspective. IFOAM. 103 p.
• Grossman Joel. 2000. Horticultural oils: New summer uses on ornamental plant pests. Bio-Integral Resource Center. PO Box 7414, Berkeley. 69-79.
• IFOAM. 2002. Norms of IFOAM basic standards for organic production and processing. IFOAM. Germany. 144p.
• Jee, H. J., Shim, C. K., Ryu, K. Y., and Choi, D. H. 2005. Effects of cooking oils on control of powdery mildew of cucumber caused by Phaerotheca fulginea. Plant Pathol. J. 21: 415p
• Jee, H. J., Shim, C. K., Ryu, K. Y., Park, J. H., and Choi, D. H. 2006. Effects of air-circulation fan and EYCOM (egg-yolk and cooking oil mixture) on production and control of powdery mildew of lettuce in the greenhouse cultivation. Plant Pathol. J.
• Jee, H. J, Shim, C, K., Park, J. H., and Ryu, K. Y. 2007. Effects of organic materials on control of diseases and insects of Chinese cabbage in organic farming. 3rd ACPP proceeding. 325p.
• Ko, W. H., Wang, S. Y.,  Hsieh, T. F. and Ann, P. J. 2003. Effects of sunflower oil on tomato powdery mildew caused by Oidium neolycopersici. J. Phytopathology 151: 144-148.
• Cyclo (L-Pro-L-Tyr) from plant growth promoting Rhizobacterium, Bacillus amyloliquefaciens strain EXTN-1 induce systemic resistance against Colletotrichum orbiculare in cucmber plant. 6th International Workshop on PGPR. India. 503-507 2003 (1/3).
• Park, K. S. et. al. 2003. Plant growth promotion and bioprotection against multiple plant pathogens by a selected PGPR-mediated ISR, B. amyloliquefaciens EXTN-1. 6th International Workshop on PGPR. India. 496-502pp.
• Park, K. S. 2004. Plant growth promotion and induced systemic resistance by a selected PGPR strain, B. amyloliquefaciens EXTN-1. KSPP Annual meeting and International Symposium. Korea.
• Rural Development Administration. 2005. A guide book for the substances permitted to use in organic farming. NIAST. 192p
• Trdan S, Valic N., Jerman J., Ban D. and Znidarcic D. 2004. Efficacy of three natural chemicals to reduce the damage of Erysiphe cichoracearum on chicory in two metrorologically different growing seasons. J. Phytopathology 152: 567-574.
• Trujillo F., Nock JP, and Fupferman JF. 2003. Effects of lecithin, calcium and antioxidant formulation on superficial scald and internal breakdown of Granny Smith apples. Plant Dis. 87: 39-44.
• Zhu, Y. Y., Fang, H., Wang, Y. Y., Yang, S. S., Mew, T. W., and Mundt, C. C. 2005. Panicle blast and canopy moisture in rice cultivar mixtures. Phytopathology 95: 433-438.
• Zhu, Y. Y. et. al. 2000. Genetic diversity and disease control in rice. Nature. 406: 718-722.

Index of Images

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  Table 1 Patent Microbes Used for Bio-Fertilizer Production in Korea

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  Table 2 Plants Showing Growth Promotion by Extn-1 Treatment Depending on Soil Type

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  Table 3 Effect of Soil Drenching of Extn-1 on Growth of Chinese Cabbage and Lettuce

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  Table 4 Effect of Extn-1 on Control of Tomato Bacterial Wilt Caused by Ralstonia

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  Table 6 List of Registered Bio-Fungicides in Korea in 2007

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  Table 7 List of Registered Bio-Insecticides in Korea in 2007

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  Table 8 Effect of Eyco on Control of Powdery Mildew and Downy in Cucumber in a Farmer's Greenhouse

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  Table 9 Effect of Eyco and Air Circulation Fan (Acf) on Lettuce Yield in a Greenhouse

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  Figure 1 Effective Concentration of Eyco on Control of Powdery Mildew in Cucumber in the Greenhouse.

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  Table 5 Effect of Extn-1 on Suppression of Fusarium Wilt and Yield of Hot Pepper in the Field

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  Table 10 Comparisons of Yield of Organic Chinese Cabbage among Treatments of Environment-Friendly Materials

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  Table 11 Effect of Canola Eyco and BT (Bacillus Thringiensis) Mixture on Suppression of Diseases and Insect Damage on Organic Chinese Cabbage in Fields

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  Table 12 Effect of Eyco and Other Environment-Friendly Materials on Control of Thrip in Lettuce

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  Table 13 Comparison of Lettuce Yield among Treatments

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