• Research in Plant Disease
• /
• v.12 no.3
• /
• pp.278-283
• /
• 2006

The effect of calcium cyanamide($CaCN_2$) on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.5
• /
• pp.668-674
• /
• 2014

The objective of the present study was to investigate the protective and free radical scavenging effects of conventionally and organically cultivated kale juices against oxidative damage in $LLC-PK_1$ cells. The DPPH, NO, $O_2{^-}$, and ${\cdot}OH$ radical scavenging activities of organically cultivated kale were higher than those of conventionally cultivated kale juice. Oxidative damage induced by AAPH (2,2'-azobis(2-amidinopropane) dihydrochloride), SNP (sodium nitroprusside), pyrogallol, and SIN-1 (3-morpholinosydnonimine) led to loss of cell viability and increased lipid peroxidation in LLC-PK1 cells, whereas treatment with vegetable juices, especially organically cultivated kale juices, significantly increased cell viability and inhibited lipid peroxidation in a dose-dependent manner (P<0.05). These results suggest that organically cultivated kale juices have protective roles against oxidative stress induced by free radicals.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.1
• /
• pp.57-62
• /
• 2001

Twelve antagonistic strains against Fusarium wilt of watermelon-rootstock gourd were selected from 54 bacterial isolates which were isolated from the rhizosphere of crop plants growing in various locations. They showed strong inhibitory effects on growth of Fusarium osysporum f. sp. niveum, the causal agent of watermelon-rootstock gourd Fusarium wilt. Among these antagonists, the isolate YJ-3 was the most pronounced in growth-promoting ability for watermelon-rootstock gourd. The growth of watermelon-rootstock gourd in bed soil inoculated with YJ-3 was better by 46 and 13% than those in commercial bed soil alone and in bed soil inoculated with commercial microbial inoculant, respectively. The antagonistic plant growth-promoting rhizobacterium, strain No. YJ-3, was identified as Bacillus sp. on MIDI system. Furthermore, Bacillus sp. YJ-3 showed antifungal activity on growth against Alternaria cucumerina, Botrytis cinerea, Colletotrichum orbiculare, Didymella bryoniae, Rhizoctonia solani and Fusarium oxysporum.

• The Korean Journal of Mycology
• /
• v.44 no.3
• /
• pp.171-175
• /
• 2016

A gram-negative bacterium was isolated from spent substrates of Agaricus bisporus and showed significant antagonistic activity against Pseudomonas agarici. The bacterium was identified as Alcaligenes sp. based on cultural, biochemical, physiological characteristics and a 16S rRNA sequence analysis. The isolate is saprophytic, but not parasitic or pathogenic on cultivated mushroom, whereas it showed strong inhibitory effects against P. agarici cells in vitro. The control efficacy of Alcaligenes sp. HC12 against brown blotch of P. agarici was up to 63% on Agaricus bisporus. The suppressive bacterium may be useful for the development of biocontrol systems.

• Journal of Mushroom
• /
• v.17 no.1
• /
• pp.19-23
• /
• 2019

A gram-positive bacterium was isolated from the spent substrate of Agaricus bisporus that showed a marked antagonistic activity against Pseudomonas agarici. It was identified as Bacillus safensis HC42 based on its cultural, biochemical, and physiological characteristics, and 16S rRNA sequence. B. safensis HC42 was saprophytic, but not parasitic or pathogenic, in cultivated mushrooms and showed strong inhibition of P. agarici in vitro. Moreover, it showed a control efficacy of 66 % against browning disease caused by P. agarici in Agaricus bisporus. Therefore, B. safensis HC42 may be useful in the future for the development of a biocontrol system.

• Research in Plant Disease
• /
• v.27 no.4
• /
• pp.172-179
• /
• 2021

This study aimed to assess the disease incidence and distribution of toxigenic in Korean triticale. The pathogen of triticale that cause Fusarium head blight were isolated from five different triticale cultivars that cultivated in Suwon Korea at 2021 year. The 72 candidate were classified as a Fusarium asiaticum by morphology analysis and by ITS1, TEF-1α gene sequence analysis. And the results of pathogenicity with 72 isolates on seedling triticale, 71 isolates were showed disease symptom. Also, seven out of 71 Fusarium isolates were inoculated on the wheat, to test the pathogenicity on the different host. The results showed more low pathogenicity on the wheat than triticale. The results of analysis of toxin type with 72 isolates, 64.6% isolates were produced nivalenol type toxin and other 4.6% and 30.8% isolates were produce 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, respectively. To select fungicide for control, the 72 Fusarium isolates were cultivated on the media that containing four kinds fungicide. The captan, hexaconazole, and difenoconazole·propiconazole treated Fusarium isolates were not showed resistance response against each fungicide. However, six isolates out of 72 isolates, showed resistance response to fludioxonil. This study is first report that F. asiaticum causes Fusarium head blight disease of triticale in Korea.

• Korean Journal of Weed Science
• /
• v.13 no.2
• /
• pp.151-158
• /
• 1993

This experiment was conducted in order to understand the intra-and the inter-competition of arrowhead, Sagittaria trifolia L., under the conditions of arrowhead monoculture and rice-mixed culture, respectively. In arrowhead monoculture, the infra-specific competition in both shoot length and floral axis number began at 10 plants per $0.5m^2$ and that in leaf number, leaf length, dry shoot weight and formated tuber number did at 5 plants per $0.5m^2$. In the inter-specific competition according to arrowhead density in the constant rice-mixed culture, the plant height and the tiller number of rice decreased at 15 and 5 plants of arrowhead per $0.5m^2$, respectively. The dry top weight and the formated tuber number of arrowhead decreased with increase of arrowhead density. In the inter-competition according to rice plant density in the constant arrowhead-mixed stands, the dry matter weight and the produced tuber number of arrowhead decreased with increase of rice plant density and the plant height and the tiller number of rice also did with that. In the different transplantation time of rice, the growth in arrowhead became less in order of late transplantation>standard one>early one and the plant height and the tiller number of rice became more in order of that by comparing the percentage of growth under the mixed culture to that under the arrowhead monoculture.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.4
• /
• pp.253-259
• /
• 2013

The use of subsurface drip fertigation using slurry composting bio-filtration (SCB) as nitrogen (N) fertilizer source can be beneficial to improve fertilizer management decision. The objective of this study was to evaluate effects of SCB liquid fertilizer by subsurface drip fertigation on cucumber (Cucumis sativus L.) yield and soil nitrogen (N) distribution under greenhouse condition. Cucumber in greenhouse was transplanted on April $4^{th}$ and Aug $31^{st}$ in 2012. N sources were SCB and urea. Four N treatments with 3 replications consisted of control (No N fertilizer), SCB 0.5N + Urea 0.5N (50:50 split application), SCB 1.0N, Urea 1.0N. 100% of N recommendation rate from soil testing was denoted as 1.0N. The subsurface drip line and a tensiometer were installed at 30 cm soil depth. An irrigation was automatically started when the tensiometer reading was -15 kPa. The growth of cucumber at 85 days after transplanting was 5% higher in all N treatment than control. Semi-forcing culture produced more fruit yield than retarding culture. Fruit yields were 62.2, 76.3, 76.4, and 75.1 Mg $ha^{-1}$ for control, SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, respectively. Although fruit yields were similar under SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, 176 kg K $ha^{-1}$ can be over applied if cucumber is grown twice a year under SCB 1.0N that may result in K accumulation in soil. N uptake was 172, 209, 213, 207 kg $ha^{-1}$ for control, SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, respectively. N use efficiency was the highest (37%) at SCB 0.5N + Urea 0.5N under semi-forcing culture. Nitrate-N concentration in soil for all N treatments except control in semi-forcing culture was the highest between 15 and 30 cm soil depth at the 85 days after transplanting and between 0 and 15 cm soil depth after cucumber harvest. These results suggested that SCB 0.5N + Urea 0.5N can be used as an alternative N management for cucumber production in greenhouse if K accumulation is concerned.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.24 no.3
• /
• pp.75-79
• /
• 1979

These studies were designed to define the effects of temperature on the vegetative growth of the korean ginseng, the induction and growth of the ginseng callus and organ differentiation from the callus of ginseng. At the temperature over $25^{\circ}C$. the plant growth of ginseng was significantly decreased and the chlorophyll in the .central parts of leaflets was deteriorated. Induction and growth of the ginseng callus was best at $25^{\circ}C$. High temperature of $29^{\circ}C$ promoted the initiation of roots from callus tissue but the shoot was not initiated at the temperature over $25^{\circ}C$. Shoots initiation from the ginseng callus occurred at $21^{\circ}C$ or lower temperature.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.6
• /
• pp.353-355
• /
• 2000

The seasonal occurrence of aphids was investigated in the soybean Held to increase the control efficiency of aphid vectors of Soybean Mosaic Virus. The patterns of aphids occurrence were different according to planting time. There were two peaks in late June and mid-August in aphid population in optimum seeding (May 20), whereas the peak was around mid-June in early seeding(Apr, 20). Acyrthosiphon solani was dominant Species in early seeding, while Aphis glycines was dominant in optimum seeding. In early seeding, SMV incidence increased rapidly between 20 June and 30 June, suggesting that virus spread was strongly correlated with increased colonization of aphids. Imidacloprid WP, benfuracarb EC and acephate WP showed a good effect for the control of aphids without phytotoxicity. In the plot with infurrow treatment of imidachloprid G until 52 days after shooting, aphids were controled effectively. Acephate WP was applied as a foliar spray at V4, V6, or V4/V6 stage and all the treatments were effective on reducing: SMV incidence.