• Journal of Mushroom
• /
• v.20 no.3
• /
• pp.127-137
• /
• 2022

Effects of substrate bed interior environments on mushroom qualities were investigated in oyster mushroom cultivation facilities in which either Reversible Air-Circulation Fans (RACF) blowing air in two directions (upwards and downwards) or customary Convection Fans (CF) with air blowing only upwards were operated throughout the cultivation period. Two days before harvest, the deviation ranges of the bed interior temperature and relative humidity in the facility using RACF were in the ranges of 1.0-1.3℃ and 7.8-9.0% in the first growing cycle, and within 0.7-1.1℃ and 10.0-11.4% in the second cycle. In the facility using CF, the ranges of variation in the indoor environment parameters (5.8-6.4℃ and 21.3-23.1% in the first growing cycle, and 3.4-5.7℃ and 14.6-18.3% in the second growing cycle) were much enlarged compared to those associated with RACF. These results strongly indicate that RACF significantly enhances air uniformity. Some mushroom qualities differed between growing cycles. For instance RACF in the first cycle gave somewhat better qualities than CF, but some qualities, like pileus diameter and stipe length, were slightly lower than those described for CF in the second cycle when the cultivation substrate weakened. The observation that some qualities worsened under RACF conditions, despite better air uniformity during the growing cycle, revealed the possibility that downward wind may exert a non-negligible negative effect on mushroom growth. Therefore in the future, making wind measurements on the interior and exterior of substrate beds is necessary to obtain insights into their influences on mushroom qualities. The RACF operation manual needs to be edited to convey this necessity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.4
• /
• pp.462-469
• /
• 2009

This study was conducted to investigate total polyphenolic contents and reactive oxygen species (ROS) scavenging effects of extracts from peels of ten Jeju native citrus fruits according to the harvest from August 2006 to February 2007. Total polyphenolic contents from methanol extracts of citrus peel were the highest in Jigak (Citrus aurantium) and Hongkyool (C. tachibana) by over 200 mg% in the unmatured period, from the late August to the late September, and all the citrus peels mostly decreased while ripening. Scavenging effect of superoxide anion radical showed good correlation with total polyphenolic contents. The unmatured periods of Hongkyool and Jigak were the highest with more than 60%. Hydrogen peroxide scavenging activity was the highest in Sadoogam (C. pseudogulgul) at 73.8% in late August and the second highest activity was observed in Jigak at near 70%, and all the citrus peels decreased during ripening. Hydroxy radical scavenging activity were the highest among all the ROS scavenging activities, especially in the Jigak and Dangyooja (C. grandis) at 75.1% and 74.6%, respectively, and not much affected by increased maturity of the fruits. Nitric oxide radical scavenging activity was the highest in Bungkyool (C. platymama) at 58.4% in late February, and increased with fruit ripening. In this study, Jigak was generally the highest in the polyphenolic contents and ROS scavenging activities, so the further studies are needed for industrial applications.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.4
• /
• pp.450-457
• /
• 2019

Objective : Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. Methods : We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. Results : The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ${\geq}37.3%$ was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, $5.8{\pm}5.7months$; subsidence, $0.99{\pm}0.50months$; and instrument failure, $9.13{\pm}0.50months$. Conclusion : We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various preoperative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

• Korean Journal of Agricultural Science
• /
• v.45 no.1
• /
• pp.19-27
• /
• 2018

To study the effect of natural anti-microbial chemicals on the growth and quality of chili peppers, chitosan ($100mg/L^{-1}$), stevia ($250mg/L^{-1}$), and the mixture of both chemicals at the same concentration were sprayed after planting at 1-week interval throughout the experimental period. Plant height was measured twice after the $3^{rd}$ and $4^{th}$ applications. Plant height was numerically reduced in all chemical treatments compared to that of untreated control; however, there was no statistical difference between treatments. The fruit quality was examined at commercial maturity, and only minor differences were found in fruit color, length, and dry matter content between the treatments. Although a statistical difference was not present for soluble sugars levels, total phenolics, and capsaicin contents, yield in all chemical treatments significantly increased compared to untreated control. The effect on yield increase was greater at the late harvest season regardless of treatments. Total yield of 4 harvests was higher for the chitosan treatment than other treatments. During the experiment, the entire experimental field was waterlogged for 1 day due to sudden heavy rainfall, which resulted in the occurrence of bacterial browning disease in all treatments. The rate of disease occurrence and the degree of severity, however, were much lower in the chitosan treatment. In conclusion, the potential of chitosan as an alternative antimicrobial agent was confirmed in chili peppers in this study. Further research is required on stevia as an alternative chemical for disease control in chili peppers.

• Journal of Environmental Science International
• /
• v.29 no.10
• /
• pp.989-996
• /
• 2020

This study was conducted to determine the effect of low temperature and low radiation conditions on the yield and quality of hot pepper at an early growth stage in Korea. In plastic greenhouses, low temperature, low temperature with covered shading treatments were set 17 to 42 days after transplanting. The pepper growing degree days decreased by 5.5% due to the low temperature during the treatment period. Radiation decreased by 74.7% due to the covered shading. After commencing treatments, pepper plant growth decreased with low temperature and low radiation. Analysis of the yield showed that the first harvest was delayed by low radiation. The cumulative yields of 119 days after transplanting were 1,956, 2,171, and 2,018 g/㎡ for control, low temperature, and low temperature with low radiation respectively. Capsaicin and dihydrocapsaicin concentrations in pepper fruit decreased with low temperature and low radiation. To investigate the photosynthetic characteristics according to the treatment, the carbon dioxide reaction curve was analyzed using the biochemical model of photosynthesis. Results showed that the maximum photosynthetic rate, V_cmax (maximum carboxylation rate), J (electric transportation rate), and TPU (triose phosphate utilization) decreased at low temperatures; the maximum photosynthetic rate, J, and g_m (dark respiration rate) were reduced by shading. These results indicate that low temperature and low radiation can retard early growth, yield, and quality, but these can also be recovered 119 days after planting. Based on the results, the yield and quality of pepper can recover from abiotic stresses with proper cultivation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.4
• /
• pp.209-213
• /
• 2006

This study was carried out to investigate the changes in soil chemical properties and yields of crops by rice-soybean rotation cropping system at silt loam soil. There were 4 rotation cropping systems; continuous rice cultivation, annual, biennial and triennial rotation of soybean and rice. There were little change in pH, organic matter, $Ca^{2+}$ and $K^+$ contents with decrease in available phosphate content in the continuous rice cropping. The cropping system of soybean-rice caused to increase in available $P_2O_5$, $K^+$ and $Ca^{2+}$ in the soil after harvest. Content of $NH_4-N$ in the soil also increased after the rotation of soybean than the continuous rice cropping in the soil during the rice growth period. These chemical change in the soil caused to increase rice growth in number of the panicles and the spikelet per square meter. The yield of rice was increased by the rotation with soybean, and was gradually increased in the triennial rotation of soybean and rice. But the yield of soybean was decreased in continuous cultivation for two or three years in the paddy field. It was recommended for annual rotation to prevent the yield of soybean from decrease.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.1
• /
• pp.103-112
• /
• 1995

Six African rice varieties, two each from three types having the characteristics of partially, irregularly, and completely developed abscission layers, were selected and grown 1） to investi-gate the histological differences during the formation and development of the abscission layers and 2） to evaluate the changes in the breaking tensile strength required to detach a grain from its pedicel dur-ing ripening period in relation with developmental stage of the abscission layers. In African rice, the panicle and spikelet grew rapidly from 15 days before heading and almost completely grown in length at five days before heading. The abscission regions were recognized at 15 days before heading. However, any apparently developed abscission layers were not recognized in the lemma side for partially developed abscission layers. A group of parenchymatous cells could be observed sporadically in the abscission layers of the lemma side for irregularly developed ab-scission layers. At ten days before heading, abscission layers consisting of one or two layers of parenchymatous cells were clearly distinguished from neighboring cells due to thickened and lignified cell walls. There were a number of individual parenchymatous cells scattered sporadically in the lemma side of partially developed abscission layers, and a number of grouped parenchymatous cells scattered randomly in the lemma side of irregularly developed abscission layers. At two weeks after heading, the grains became almost fully filled. The cracking of abscission layers between rachilla and pedicel was observed, and the breaking tensile strength required to detach a grain from its pedicel was as low as that at harvest time.

• Journal of Life Science
• /
• v.24 no.7
• /
• pp.750-756
• /
• 2014

Citrus, yield of which is the highest among fruits produced in Korea, is extensively consumed for processed food items. The amount of by-products of citrus produced from the processing within a short period after the harvest is tremendous. These by-products are mostly dumped into land or neglected because of cost involved in processing them. The aim of the present study was to explore the usefulness of the by-products as a new material by examining the anti-inflammatory activity of fermented extracts of citrus peels. The peels of 'unshu' (Citrus unshiu) was fermented with Aspergillus niger and their extracts before or after fermentation were analyzed using HPLC. The analysis showed that neohesperidin level considerably increased and the two new compounds were synthesized after fermentation. The anti-inflammatory activity of the fermented extracts was examined on RAW 264.7 murine macrophage cells stimulated with lipopolysaccharide. Fermented unshu extracts significantly enhanced the decrease of nitric oxide (NO) production, iNOS and COX-2 expression, comparing with those of unfermented extracts. Also TNF-${\alpha}$ and IL-6 production, both of which are pro-inflammatory cytokine, were more inhibited in fermented extracts. These results showed that the fermentation and promotion of the function of the by-products of citrus peels will help find a new application.

• Korean journal of applied entomology
• /
• v.21 no.2 s.51
• /
• pp.78-86
• /
• 1982

The ecological studies were conducted to identify some bark-beetles on apricot and plum trees in Jeonnam province. Harmful bark-beetles caught from apricot and plum trees were identified as Scolytus seulensis. Xyleborus atratus., X. germanus, X. rubricollis and X. saxeseni. The seoul barkbeetle emerged during the period from early May to late October $1980\~1981$, it happens twice in a year, with the peak July 10 and August 25 in 1950, July 15 and August 20 in 1981. A daily peak emerged for adults was at 11 AM to 1 PM. Distribution of holes on the apricot stems varied; more than 100 holes per meter in Henderson (Apricot) and Y-49057 (Apricot), 12 holes per meter in Derbyroyal (Apricot). Comparatively more holes were found in the European variety, and the cardinal distribution was in the order of east, south, west and north. The longer the longth of the mother-gallery, the greater number of egg-gallery found. Optimum temperature for mating was $27^{\circ}C$. The time for mating was longer during May-June than July-August. The fruit weight of damaged plum tree reached 12.25g around four weeks after flowering; where as that of normal tree increased up to 63.5g at harvest time. The natural enemy of the seoul bark beetle was Eurytoma sp. They were found as mature larva or pupa and they emerged from early May to the middle of June. Adult longevity was about a week.

• The Korean Journal of Pesticide Science
• /
• v.2 no.3
• /
• pp.85-89
• /
• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.