• Korean Journal of Organic Agriculture
• /
• v.18 no.4
• /
• pp.613-626
• /
• 2010

Coming with the well-being era, consumer's demand for safe agricultural products is increasing. It is urgent to develop an environment-friendly pear production system. Accordingly, this study was conducted to develop an environment-friendly pear production system by using several environment-friendly agricultural materials which is known to be effective in agricultural production. In the effects of environment-friendly agricultural materials on the soil chemical characteristics in pear orchard, the content of total carbon, organic matter, Ca and Mg increased a little respectively compared with those of 2008, and 2nd treatment showed the highest EC and Mg content in the soil among treatments. The content of leaf N, P and Ca in 2009 decreased compared with those of 2008, while Mg content showed no difference between 2008 and 2009 years. Average pear weight in 2009 was 31g higher than that of 2008 (682g) and 2nd treatment showed the highest pear weight (738g) among treatments. The average sugar content was higher in 2009 (12.6$^{\circ}Bx$) compared with that of 2008 (12.2$^{\circ}Bx$) and the plot of 2nd treatment highest sugar content (12.6$^{\circ}Bx$) among treatments. There were no difference in hunter value of L among treatments, but hunter value of a showed higher 1.62 in 2009 than that of 2008 (3.73). The highest of gumminess and cohesiveness of fruits were obtained from 1st treatment and adhesiveness and chewiness of fruits were obtained from 3rd and 1st treatment respectively. Firmness of fruit increased a little in 2009 compared with that of 2008, while the highest firmness was obtained from 3rd treatment with 1.63kg/5mm$\oint$ among treatments. Phosphate content in the peel of 'Niitaka' pear of fruit skin in 2009 (0.97g/kg) showed 0.06g/kg more content than that of 2008 (0.91g/kg), while the highest content was obtained from 3rd treatment (1.15g/kg). Potassium content in the peel of 'Niitaka' pear in 2009 was 8.20g/kg, which is 0.06g/kg more content than that of 2008 (7.82g/kg) and the highest content was obtained from 1st treatment (8.34g/kg) among treatments. The highest nitrogen content in the flesh of 'Niitaka' pear was obtained from 3rd treatment (4.32mg/g), while it was the lowest in control plot (3.10mg/g). Phosphate content in the flesh of 'Niitaka' pear in 2009 (8.20g/kg) showed 0.06g/kg more content than that of 2008 (7.82g/kg), while the highest content was obtained from 1st treatment (8.34g/kg). There were no difference of the potassium content in the fruit peel of 'Niitaka' pear between years, but 1st treatment showed the highest content (11.81g/kg) among treatments, while the lowest was obtained from the control plot (10.83g/kg).

• Research in Plant Disease
• /
• v.21 no.4
• /
• pp.273-279
• /
• 2015

Major diseases and insect pests in nursery season of strawberry were anthracnose, powdery mildew, Fusarium wilt, two-spotted spider mite, and aphids. Environmental-friendly and chemical application schedules can improve diseases and insect pests control with relatively fewer organic and chemical materials inputs compared with spray programs when it's occurred. Field experiments were performed in 2012 to 2013 according to calendar-based spray programs with environmental-friendly spray calendar (EFSC) and conventional chemical spray calendar (CSC) for controlling diseases and insect pests of strawberry plants cv, Seolhyang during the two nursery seasons. EFSC did reduce the incidence of diseases and insect pests as compared to the non-treated control. Incidence of anthracnose and powdery mildew by EFSC and CSC was similar in 2012 and 2013 seasons. In addition, occurrence of two-spotted spider mite in EFSC in 2013 was similar to those of CSC and was shown highly in early and mid-June both 2012 and 2013 seasons. Occurrence of aphid in EFSC was shown highly in early and mid-June both 2012 and 2013 seasons. These results suggest that EFSC program may be effective for controlling strawberry diseases and insect pests by using environmental-friendly organic materials.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.1
• /
• pp.17-21
• /
• 2017

BACKGROUND: Castor oil and wormseed extract are important active ingredients for biopesticide, and ricinoleic acid in castor oil and three monoterpenes (ascaridole, carvacrol and p-cymene) in wormseed extract are known bioactive substances. However, their stabilities had not been studied, even though the stability was the core property for estimation of shelf-life of biopesticide. Aimed to investigate the thermal stabilities of the bioactive substances in castor oil and wormseed extracts. METHODS AND RESULTS: The contents of ricinoleic acid and three monoterpenes (ascaridole, carvacrol and p-cymene) were analyzed by gas chromatography (GC). The thermal stabilities of the bioactive substance were measured at $0^{\circ}C$, $23^{\circ}C$, $30^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$ and $54^{\circ}C$ for 84 d. The half-lives of ricinoleic acid in biopesticides was ranged from 28.9 d to 57.8 d at $30^{\circ}C$, and the stability of pure castor oil were located in the range ($t_{1/2}$=46.2d for Indian product and 27.7 d for Korean product) at the same temperature. The half-lives of the total monoterpenes in biopesticides were ranged from 3.9 d to 27.7 d at $30^{\circ}C$. Among the monoterpenes, the stability ascaridole and p-cymene were decreased in acidic condition. All the bioactive substances showed similar stability on the different thermal conditions. CONCLUSION:The half-lives of most bioactive substance from castor oil and wormseed extracts were less than 100 d. To increase the stability of bioactive substance in biopesticide, stabilizing additives like antioxidant and oxygen remover should be considered to extend of the shelf-life.

• Journal of Mushroom
• /
• v.21 no.4
• /
• pp.266-269
• /
• 2023

This study aimed to address the increasing demand for technologies preventing mushroom fly damage. By monitoring the annual occurrence patterns of pests over several years and accumulating data, we conducted an analysis to evaluate the efficacy of preventive measures applied before the surge in mushroom fly infestation, typically observed in May. For preemptive control, physical measures involved installing air curtains at cultivation facility entrances and placing sticky traps and insect traps around entry points to block external entry and reduce internal insect density. Additionally, we applied an organic agricultural material, Dalmatian chrysanthemum extract, weekly alongside chemical control measures. To assess the reduction in mushroom fly populations, yellow sticky traps (15×25 cm) were placed at three locations within the mushroom cultivation facility, and the occurrence patterns before and after implementing preventive measures were compared. Compared to conventional practices, the application of preventive techniques resulted in a significant reduction, with a 60% decrease from 15 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in May and a 40% decrease from 10 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in June. While achieving over 50% efficacy during the peak mushroom fly season with preventive measures, we identified complementary actions such as blocking external sources (gaps in cultivation facility doors) and maintaining cleanliness around cultivation facilities (proper disposal of spent substrate) for further improvement. Comprehensive analysis and safety studies, including correlation analysis with contaminants and pathogens, are recommended to ensure the widespread adoption of mushroom fly preventive techniques for safe and stable mushroom production in the agricultural sector.

• Research in Plant Disease
• /
• v.29 no.4
• /
• pp.459-463
• /
• 2023

This study was conducted to investigate the plant-parasitic nematodes of ornamental foliage plants, citrus orchards, and tea plantations from July to December 2022. As a result of the investigation of plant-parasitic nematodes in 415 foliage plants, root-lesion nematodes were detected most frequently, followed by root-knot nematodes, pin nematodes, and other nematodes. In tea plantations, spiral nematodes, cyst nematodes, and root-knot nematodes were detected. Citrus nematodes, ring nematodes, and root-knot nematodes were discovered in citrus orchards. In foliage plants, tea plantations, and citrus orchards, the detection rate of plant-parasitic nematodes was not high, but root-lesion nematodes were detected. Therefore, it is necessary to apply appropriate control methods to manage root-lesion nematodes during the cultivation of foliage, tea, and citrus plants.

• Korean Journal of Organic Agriculture
• /
• v.19 no.2
• /
• pp.255-272
• /
• 2011

This work studied the growth and yield of green crops, changes of mineral composition in greenhouse soil and green crops, and infection with wintering green crops cultivation in greenhouse field. At 74 days after seeding of wintering green crops, dry matter was 710kg/10a in rye, 530kg/10a in barley, 230kg/10a in hairy vetch, and 240kg/10a in bean or weeds. Total nitrogen content in green crops was 4.5% in pea and hairy vetch, and 3~4% in barley and rye. $P_2O_5$, CaO, and MgO contents in all green crops were about 1.0%, and $K_2O$ content was the highest level by 4~5% among macro elements. Total nitrogen fixing content in shoot green crops uptaken from soil was 22.1kg/10a in rye, 20.6kg/10a in barley, 10.6kg/10a in hairy vetch, and 9.6kg/10a in pea and giant chickweed. $P_2O_5$ fixing content in shoot green crops uptaken from soil was 8.4kg/10a in rye, 6.3kg/10a in barley, and 2.3 kg/10a in hairy vetch and pea. $K_2O$ fixing content in shoot green crops uptaken from soil was 28kg/10a in rye, 24.7kg/10a in barley, and 11kg/10a in hairy vetch and pea. CaO fixing content in shoot green crops uptaken from soil was 2~3kg/ 10a in all green crops, and MgO fixing content was 1.7~2.6kg/10a in all green crops. Pepper growth in no-tillage was not a significant difference at all green manure crops. The number of fruit and fruit weight were higher in control, pea, hairy vetch and harvest barley than rye and barley. Soil mineral compositions in wintering green crops increased at pH, organic matter, CEC compared with control. Soil chemical compositions were stable level at green crops cultivation according as decreases of EC, available phosphoric acid, Ca, and Mg contents. After no-tillage by green manure crops, pH in soils was higher in green manure crops than control. EC content in soils was lower in green manure crops than control, and was remarkably low level in barley harvest. Organic matter content in soils increased in hairy vetch and barley green manure but decreased by 35% in barley harvest. Total nitrogen and avaliable $P_2O_4$ content in soils remarkably increased but was not a significant difference at all green manure crops. Cation (K, Ca, and Mg) content in soils decreased by 15~20% in K, 2~11% in Ca, and 3~6% in Mg at rye, barley and pea compared with control.

• Korean Journal of Organic Agriculture
• /
• v.24 no.3
• /
• pp.557-570
• /
• 2016

Growth of 6-year old 'Niitaka' pear (Pyrus pyrifolia Nakai) trees and control of insect and disease occurrences were compared between fermented soybean extracts and rain-shelter system for two years. Foliar application of fermented soybean extracts was applied at 6 times as a pre-experiment in the open-field in 2013, with a rain-shelter system in 2014. Fermented soybean extract treatment increased foliar concentrations of approximately 0.46% T-N, 0.17% K, 0.19% Ca, and 0.06% Mg in 2013 compared to the control, with similar macro-nutrients between the control and soybean extract treatment observed in 2014. Rain-shelter system increased foliar concentrations of T-N, Ca, and Mg compared to the open-field. There were no significantly different between the control and soybean extract treatment for number of leaves per fruit, leaf dry weight, phytotoxicity, and completed shoot growth on August during the two years. Rain-shelter system increased leaf dry weight and did not affect phytotoxicity in the leaves. Fruit quality parameters were mostly similar to control and soybean extract treatment for two years, with higher fruit firmness observed for soybean extract treatment. Rain-shelter system advanced 4 days of harvest dates, and increased approximately 7.0 ton fruit yield per ha, 20 g mean fruit weight, and fruit soluble solid contents compared to open-field in 2014. Soybean extract treatment little suppressed occurrence of disease and insect on the leaves and fruits in both years. Rain-shelter system increased occurrence of Venturia nashicola on the leaves and to 63.8% of Gymnosporangium asiaticum on the fruits in 2014. Strong winds and storms in May elevated relative humidity in the rain-shelter system and caused high infection of the disease occurrence, requiring for an additional green control method. Soybean extract treatment little affected tree growth and would have initiated for a long-term study to evaluate tree physiological characteristics. Rain-shelter system improved fruit productivity and advanced harvest dates, which could have been more effective facility at a Thanks Giving Day between middle and end of September.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24
• /
• pp.5-38
• /
• 1991

비료(肥料)를 공업적(工業的)으로 제조(製造)하여 농업(農業)에 사용(使用)하기 시작(始作)한 이래(以來) 신비종(新肥種)의 개발(開發)에 대한 관심(關心)은 부단(不斷)히 계속(繼續)되어 왔으며 현재(現在)에도 어느 국가(國家)나 생산업계(生産業界)에서 개발(開發)을 위한 노력(努力)을 많이 기우리고 있음이 현실(現實)일 것이다. 어느 국가(國家)와 어느 시대(時代)에 있어서나 현존(現存) 비종(肥種)을 생산(生産)함에는 소비(消費)와 생산면(生産面)에서 상응(相應)하는 사정(事情)이 있었을 것이며 또한 미래(未來)에도 신비종(新肥種)을 개량(改良)하거나 창제(創製)함에는 여러 가지 관련문제(關聯問題)를 검토(檢討)하여 새로운 요구(要求)에 합리적(合理的)으로 부합(符合)되도록 설계(設計)해야 할 것이다. 비료(肥料)는 현대(現代) 농업(農業)에서 불가피(不可避)하게 사용(使用)되는 기본자재(基本資材)이며 세계적(世界的)으로 그 소비(消費)가 증가(增加)되나 국가별(國家別) 농업(農業)의 특수성(特殊性)에 맞추어서 비료(肥料)의 형태(形態)와 생산량(生産量)에 차이(差異)가 있게 되며 또 변화(變化), 개량(改良)될 것이다. 우리나라의 농업(農業)이 최근(最近) 급속(急速)히 변화(變化)되면서 생산수단(生産手段)과 경영(經營)에도 큰 변혁(變革)이 불가피(不可避)하게 따라야 할 것으로 판단(判斷)된다. 생산수단(生産手段)의 개량(改良)은 농산물(農産物) 생산가(生産價)를 낮추고 노력(勞力)의 투입(投入)을 줄이며 우수품질(優秀品質)의 농산물(農産物)을 안정적(安定的)으로 생산(生産)하기 위한 대응책(對應策)이 될 것이다. 비료(肥料)의 사용(使用)은 이러한 시대적(時代的) 요구(要求)에 맞추어 신비종(新肥種)이 개발(開發)되고 시용기술면(施用技術面)에서 발전(發展)이 있어야 될 것이다. 미래(未來)의 우리 나라 농업(農業)을 위하여 개발(開發)되어야 할 비종(肥種)의 형태(形態)와 그에 관련(關聯)되는 요건(要件)은 다음과 같이 요약(要約)된다. 1. 시비효율(施肥效率)을 높히기 위하여서나 성력재배(省力裁培)를 위하여 완효성(緩效性) 비료(肥料) 특히 질소비료(窒素肥料)의 신비종(新肥種) 개발(開發)이 절실(切實)히 필요(必要)하다고 판단(判斷)됨. 신비종(新肥種)은 대상작물(對象作物)의 종류(種類), 재배방식(裁培方式) 및 기계화(機械化) 상태(狀態)에 적합(適合)한 형태별(形態別)로 제조(製造)됨이 바람직함. 완효성(緩效性) 질소비료(窒素肥料)의 제조(製造)에는 화학합성(化學合成), 성형화(成形化), 흡착화(吸着化) 및 피복화(被覆化) 방식중(方式中) 성형화(成形化)에 의한 것이 최다(最多)이나 피복화(被覆化)도 재료(材料)와 기술(技術)의 발전(發展)에 따라 증가(增加)의 경향(傾向)임. 2. 현존(現存) 복합비료(複合肥料)의 토양(土壤) 및 작물(作物)에 대한 적합성(適合性)을 재검토(再檢討)하여 효율(效率)을 높히도록 개량(改良)함. 3. 소시비방식(少施肥方式)의 영농(營農)으로서 환경(環境)을 오염(汚染)으로부터 방호(防護)할 것이며 4. 작물종류(作物種類)(품종포함(品種包含)) 유전자형별(遺傳子型別) 비료감응성(肥料感應性)을 검정(檢定)하여 소시비(少施肥), 고효율(高效率)을 기(期)하도록함. 5 작물(作物)의 영양생리학(營養生理學) 분야(分野)에서도 비료외적(肥料外的)인 성장관련요인(成長關聯要因)의 작용(作用)을 연구(硏究)하여 응용(應用)의 가능성(可能性)을 추구(追究)함이 미래(未來)의 한 과제(課題)가 될 것으로 생각됨. 예(例): 유전공학적(遺傳工學的) 기법(技法)에 의한 성장인자(成長因子)의 개량(改良) 또는 시비효율(施肥效率)의 증대(增大) 작물성장(作物成長)과 미생물활동(微生物活動)과의 상호관계(相互關係) 등(等). 6. 가용(可用) 자원(資源)의 비료화(肥料化)를 위하여 타산업(他産業)의 부산물(副産物) 및 폐기물(廢棄物) (특히 유기질(有機質) 자원(資源))을 효율적(效率的)으로 재활용(再活用)하도록 함.

• Korean Journal of Organic Agriculture
• /
• v.24 no.3
• /
• pp.465-484
• /
• 2016

This study evaluated the antifungal activity of varying concentrations of water-soluble extracts from native plants (Vitex rotundifolia, Tetragonia tetragonoides, Artemisia capillaris, Hibiscus hamabo and Ficus carica) against Stemphylium vesicarium, Penicillium italicum, Sclerotinia sclerotiorum, Pythium ultimum, Botrytis cinerea, Rhizoctonia solani and Colletotrichum gloeosporioides. Mycelium growth of pathogenic bacteria generally decreased in a concentration-dependent manner following treatment with the water extracts from donor plants. Closer analyses indicate varying inhibitory capacities depending on the type of donor plant and pathogenic bacteria. Specifically, mycelium growth of S. vesicarium varied depending on the concentration of the water extracts from T. tetragonoides (r = -0.857, p<0.01) and A. capillarys (r = -0.868, p<0.01). Also, P. italicum and V. rotundifolia (r = -0.833, p<0.01), S. sclerotiorum and V. rotundifolia (r = -0.862, p<0.01), A. capillaris (r = -0.902, p<0.01), B. cinerea and T. tetragonoides (r = -0.896, p<0.01) showed an inverse relationship. The rate of mycelial growth inhibition of pathogenic bacteria analysed are as follows: P. ultimum 94%, B. cinerea 50%, C. gloeosporioides 80% in 100% treatment of T. teragonoides. A. capillaris inhibited S. vesicarium by 43%, P. ultimum by 90%; H. hamabo inhibited P. italicum by 50%, S. sclerotiorum by 26%, and F. carica inhibited R. solani by 74%. Total phenol content with antifungal activities are as follows: A. capillaris 16.15 mg/g, F. carica 7.81 mg/g, V. rotundifolia 6.18 mg/g, H. hamabo 5.25 mg/g, T. tetragonoides 4.41 mg/g, and total flavonoid content is as follows: A. capillaris 27.57 mg/g, V. rotundifolia 12.49 mg/g, F. carica 11.45 mg/g, H. hamabo 5.77 mg/g, T. tetragonoides 5.08 mg/g.

• Korean Journal of Organic Agriculture
• /
• v.22 no.2
• /
• pp.303-319
• /
• 2014

The study researched germination of the plants and growth of experimented bacteria according to concentration of water extract in order to provide basic data for developing natural agricultural resources by using naturalized plants including Solidago altissima, Amaranthus retroflexus and Sida spinosa. As concentration of water extract increased, most of test plants showed a decrease in relative germinability. Sida spinosa(r=-0.540, p<0.01), Physalis wrightii(r=-0.693, p<0.01), Amaranthus retroflexu(r=-0.724, p<0.01), Solidago altissima(r=-0.728, p<0.01) and Eclipta prostrata(r=-0.779, p<0.01) showed tendency of decrease in relative germinative power in order, respectively. For average germination period, as concentration of the processed group increased, the time for germination increased (r = 0.769, p<0.01) and according to donor plants and test plants, there was a little difference. Also, as concentration of water extract of donor plant, length of above-aerial part(r=-0.587, p<0.01), length of underground part(r=-0.741, p<0.01), fresh weight(r=-0.574, p<0.01) and generation of root hair decreased. An then, for growth of test fungi according to concentration of water extract of donor plants, growths of Botrytis cinerea(r=-0.266, p<0.05), Diaporthe citri(r=-0.323 p<0.01), Colletotrichum gloeosporioides(r=-0.512, p<0.01), Pythiumultimum(r=-0.581, p<0.01) and Rhizoctonia solani(r=-0.806, p<0.01) were repressed in order, respectively. For total amount of content of phenol with herbicidal and Antifungal activities, S. altissima $17.3{\pm}0.5mg/g$, A. retroflexus $13.1{\pm}0.3mg/g$, P. wrightii $12.0{\pm}0.4mg/g$, S. spinosa $9.5{\pm}0.1mg/g$ and E. prostrata L. $4.1{\pm}0.1mg/g$ showed in order, respectively. As these results are summarized, donor plants which were naturalized, have competitive advantage because they release phenolic compounds with allelopathic effect and affect on germination, growth and fungi growth on underground flora compared to native plants and they have eligibility for natural herbicide and germicide.