• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.309-318
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• 2005

Higher level of KCl application stimulated both leaf area index and leaf area duration in all cassava varieties, while the leaf and tuber number of the bitter varieties (high cyanide-level varieties) decreased in proportion to the level of KCl application. The root/shoot (R/S) ratio and harvest index (HI) were negatively related with the level of KCl application in all cassava varieties. The bitter varieties obtained the lowest R/S ratio at the level of 100 - 150 kg KCl $ha^{-1}$, while the sweet varieties (low cyanide-level varieties) acquired the highest values at the level of 50 - 150 kg KCl $ha^{-1}$. Also, the sweet varieties showed the lowest HI at the level of 250 kg KCl $ha^{-1}$, but the bitter varieties at the level of 150 kg KCl $ha^{-1}$. At 6 - 8 months after planting, the sweet varieties tended to obtain higher starch content of roots (tubers) at the level of 50 - 150 kg KCl $ha^{-1}$, while the bitter varieties at the level of 150 - 250 kg KCl $ha^{-1}$. Relatively lower level of 50 - 150 kg KCl $ha^{-1}$ was more appropriate for decreasing hydrocyanic acid (HCN) content of roots (tubers) in the sweet varieties at the harvest time, and the level of 250 kg KCl $ha^{-1}$ was adequate to decrease not only HCN content of leaves but also that of roots (tubers) in the bitter varieties during the growing period. To obtain higher yield and starch content of tubers, and lower HCN content of roots (tubers), it was recommended that the sweet varieties are applied with the level of 50 - 100 kg KCl $ha^{-1}$ and the bitter varieties with the level of 150 - 200 kg KCl $ha^{-1}$, respectively, in Latosol soils of Bogor areas, West Java.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.2
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• pp.121-126
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• 1985

Phytotron and field experiments were conducted to determine the influence of morphological growth stage and environmental temperature on synthesis and accumulation pattern of cyanogenic glycosides in sorghum cv. Pioneer 931 and Sioux at Munich technical university from 1979 to 1980. Various growth stages of sorghum plants were grown in phytotron at 4 different temperature regimes of 30/25, 25/20, 28/18 and 18/8 degree C with 35,000 Lux over 13-h days. The results obtained are summarized as follows: 1. Cyanogenic glycosides in sorghum plants were shown to have a great synthetic rate at early growth stages. The highest concentrations of hydrocyanic acid (HCN) were found at 2-leaf stage with 2384 and 1800ppm (DM basis) for Pioneer 931 and Sioux respectively. The contents of HCN were, however, however decreased markedly as morphological development, which shows a value of 173ppm (Pioneer 931) and 70ppm (Sioux) at heading stages. 2. Changes of hydrocyanic acid in sorghum plants were positive correlated with leaf weight ratio and leaf area ratio ($P{\leqq}0.1%$), while plant height shows a negative correlation with HCN contents ($P{\leqq}0.1%$). 3. Cyanogenic glycosides were accumulated in young plants mainly in leaves. During the late maturities, the contents of HCN in leaves and stalks were shown, however, a similar distribution. 4. Synthesis rates of cyanogenic glycosides were increased under high temperature. Accumulated hydrocyanic acid in the plants was, however declined when temperature exceeded 30 degree C. 5. Synthesis rates of cyanogenic glycosides were affected by nitrogen reductase activity (NRA). The concentration of hydrocyanic acid in sorghum plants was associated with increasing of nitrate-N accumulation.

• Mycobiology
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• v.42 no.2
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• pp.158-166
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• 2014

In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant.

• Journal of the Korean Chemical Society
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• v.68 no.3
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• pp.139-145
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• 2024

This study aims to elucidate the mechanism involved in the hydrolysis of the hexacyanoferrate(III) complex ion (Fe(CN)₆^3-) and the mechanism leading to the formation of Prussian blue (Fe^III₄[Fe_II(CN)₆]₃·xH₂O, PB) in acidic aqueous solutions at moderately elevated temperatures. Hydrolysis constitutes a crucial step in generating PB through the widely used single-source or precursor method. Recent PB syntheses predominantly rely on the single-source method, where hexacyanoferrate(II/III) is the exclusive reactant, as opposed to the co-precipitation method employing bare metal ions and hexacyanometalate ions. Despite the widespread adoption of the single-source method, mechanistic exploration remains largely unexplored and speculative. Utilizing UV-vis spectrophotometry, negative-ion mode liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and a devised reaction, this study identifies crucial intermediates, including aqueous Fe^2+/3+ ions and hydrocyanic acid (HCN) in the solution. These two intermediates eventually combine to form thermodynamically stable PB. The findings presented in this research significantly contribute to understanding the fundamental mechanism underlying the acid-catalyzed hydrolysis of the hexacyanoferrate(III) complex ion and the subsequent formation of PB, as proposed in the sequential mechanism introduced herein. This finding might contribute to the cost-effective synthesis of PB by incorporating diverse metal ions and potassium cyanide.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1578-1583
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• 2008

Rhizobacteria are used as inoculants to enhance crop yield and for biological control of fungal pathogens. Fluorescent pseudomonads isolated from the rhizosphere of groundnut showed suppression of the phytopathogen Macrophomina phaseolina that causes charcoal rot of groundnut, an economically important agroproduct. Two strains of fluorescent pseudomonads, designated as PS1 and PS2, were selected as a result of in vitro antifungal activity. After 5 days of incubation at $28{\pm}1^{\circ}C$, both PS1 and PS2 caused clear inhibition zones in dual cultures, restricting the growth of M. phaseolina by 71 % and 74%, respectively. Both the strains were capable of producing siderophores, indole acetic acid, and hydrocyanic acid, and causing phosphate solubilization under normal growth conditions. These strains, when used as inoculants in groundnut, enhanced germination up to 15% and 30% with subsequent increase in grain yield by 66% and 77%, respectively. Conversely, when the pathogen alone was tested 57% decrease in yield was recorded. Thus the studies revealed the potential of the two pseudomonads not only as biocontrol agents against M. phaseolina, but also as a good growth promoter for groundnut.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1388-1393
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• 2000

The present study was conducted to examine the feasibility of utilising bamboo (Bambusa arundinacea) shoot shell (BSS) in ruminants. Chemical composition, rumen degradability and some antinutritional compounds were determined for fresh and boiled BSSs to evaluate its feed value and safety. Thirty-two Holstein heifers were allocated to four groups and used to investigate the response in growth rate to supplementing ammoniated rice straw with fresh shell (phase 1) or silage of boiled BSS (phase 2). All animals were offered ammoniated straw ad libitum with 1kg of cotton seed meal (phase 1) or 0.5 kg of cotton seed meal and 0.5 kg of concentrate mixture (phase 2) per head per day. The BSS was supplemented at levels of 0, 3, 6 or 9 kg/d (phase 1) and 0, 5, 10 or 15 kg/d (phase 2) (as fed basis). The BSS was very high in moisture content, and its contents of crude protein and neutral detergent fiber were 13~16% DM and 65~76% DM, respectively; boiling resulting in higher moisture and protein. No hydrocyanic acid was detected in both BSSs and content of tannins was negligible. Rumen degradability of BSS was reasonably high, and with boiling the rapidly degradable fraction decreased, and potentially degradable component increased. Silage of the boiled BSS was slightly lower in both rapidly and slowly degraded fractions than the fresh BSS. Animals consumed all supplemented BSSs without any adverse health problems. Intake of ammoniated straw decreased with the increasing levels of BSS, but total intake was higher in almost all supplementary groups than in the non-BSS. Heifers had a higher growth rate in phase 1 with fresh BSS than in phase 2 with ensiled shell, and daily weight gains were 622, 629, 744 or 690 g in phase 1, and 578, 575, 677 or 635 g in phase 2 at four BSS levels, respectively. For both phases growth rate was significantly higher for the animals in groups 3 and 4 than those in groups 1 and 2 (p<0.01), with little difference between groups 1 and 2 (p>0.05) but significant difference between groups 3 and 4 (p<0.05). Supplementation with BSS also resulted in an improved feed conversion rate, with the least concentrate consumption in group 3 for both phases. It is concluded that the BSS has a high potential nutritional value as indicated by its medium protein content, reasonably high rumen degradability, and that inclusion of BSS in ammoniated rice straw diet is not only safe to animals, but also may improve growth rate of ruminants and feed conversion rate. It may be disadvantageous to use high amounts of BSS in ammoniated straw diets.