• Journal of Ginseng Research
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• v.44 no.3
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• pp.413-423
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• 2020

Background: Ginseng berries (GBs) show temporal metabolic variations among different maturation stages, determining their organoleptic and functional properties. Methods: We analyzed metabolic variations concomitant to five different maturation stages of GBs including immature green (IG), mature green (MG), partially red (PR), fully red (FR), and overmature red (OR) using mass spectrometry (MS)-based metabolomic profiling and multivariate analyses. Results: The partial least squares discriminant analysis score plot based on gas chromatography-MS datasets highlighted metabolic disparity between preharvest (IG and MG) and harvest/postharvest (PR, FR, and OR) GB extracts along PLS1 (34.9%) with MG distinctly segregated across PLS2 (18.2%). Forty-three significantly discriminant primary metabolites were identified encompassing five developmental stages (variable importance in projection > 1.0, p < 0.05). Among them, most amino acids, organic acids, 5-C sugars, ethanolamines, purines, and palmitic acid were detected in preharvest GB extracts, whereas 6-C sugars, phenolic acid, and oleamide levels were distinctly higher during later maturation stages. Similarly, the partial least squares discriminant analysis based on liquid chromatography-MS datasets displayed preharvest and harvest/postharvest stages clustered across PLS1 (11.1 %); however, MG and PR were separated from IG, FR, and OR along PLS2 (5.6 %). Overall, 24 secondary metabolites were observed significantly discriminant (variable importance in projection > 1.0, p < 0.05), with most displaying higher relative abundance during preharvest stages excluding ginsenosides Rg1 and Re. Furthermore, we observed strong positive correlations between total flavonoid and phenolic metabolite contents in GB extracts and antioxidant activity. Conclusion: Comprehending the dynamic metabolic variations associated with GB maturation stages rationalize their optimal harvest time per se the related agroeconomic traits.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.33-37
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• 1977

This study was made in order to determine which Gibberella species were occurring on rice stems and seeds in the field, and their survival 5 months after harvest time. An average 12% of plants infected with 'Bakanae' disease occurred in 4 fields planted with non-treated seed. Prior to harvest, more perithecia of Gibberella moniliformis occurred on infected rice stems than of Gibberella rosea. But Gibberella rosea was most common on the seed, and perithecia of this species also survived best until spring. F. moniliforme, F. roseum and Ophiobolus sp. were isolated from seedlings planted from naturally infected seed at the rates of 10, 25 and 8% respectively and from infected stems at rates of 3, 10 and 2% respectively. Perithecia of Gibberella rosea survived through the winter on naturally infected rice stems when kept dry indoors, buried in field soil, or places in straw stackes in the field. They did not survive on straw left on the soil surface during the very cold and dry conditions of the 1976-'77 winter.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.214-218
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• 2009

Sweetpotato [Ipomoea batatas (L.) Lam] leaves are excellent source of low molecular weight antioxidants such as polyphenols, anthocyanins and carotenoids compared to other leafy vegetables. Endogenous antioxidants in sweetpotato help our bodies to prevent ageing, heart diseases and cancer. In this study, to develop the proper cultivars for the functional feed materials, we investigated the contents of anthocyanin, $\beta$-carotene, and polyphenols as well as DPPH radical scavenging activity in leaves of 14 different cultivars at the time of the harvest. They showed a diverse antioxidation activity. In DPPH radical scavenging activity, cultivars of Nanjing 9, Yulmi and Shinzami showed higher activity, whereas cv. Huiza 6 showed the lowest. Cultivars of Shinzami and Shinhwangmi had the highest anthocyanin (3.5 mg/g fr wt) and polyphenol (15.8 mg/g fr wt) content, respectively. Interestingly, there was a high correlation between cultivars with colorful pigments in storage roots and antioxidants activity in leaves. These results suggest that sweetpotato leaves with high antioxidant activity at harvest would be suitable for functional feed materials.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1900-1911
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• 2015

In this paper, we introduce backscatter communication for power-limited sensors to enable long-range transmission in wireless sensor networks, and envision a way to avoid doubly near-far problem in wireless-powered communication network (WPCN) with this technology. In backscatter based WPCN, users harvest energy from both the signal broadcasted by the hybrid access point and the carrier signal transmitted by the carrier emitter in the downlink, and then transmit their own information in a passive way via the reflection of the carrier signal using frequency-shift keying modulation in the uplink. We characterize the energy-free condition and the signal-to-noise ratio (SNR) outage zone in backscatter based WPCN. Further, we propose backscatter based harvest-then-transmit protocol to maximize the sum-throughput of the backscatter based WPCN by optimally allocating time for energy harvesting and information transmission. Numerical results demonstrate that the backscatter based WPCN increases significantly the transmission range and diminishes greatly the SNR outage zone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.1016-1019
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• 1995

This study was conducted to investigate the nutrient composition of hydroponic water dropwort and the effect of blanching condition on ascorbic acid content. Nutrient composition of hydroponic water dropwort of mid harvest on the 30th day was measured in three portions of leaves, petioles and stems, and was compared with that of late harvest on the 40th day. Hydroponic water dropwort was obtained from the Department of Horticultural Science, Seoul National University. The results were as follows. The nutrients content of leaves were significantly higher in ash and ascorbic acid and lower in moisture, crude fat and crude fiber than those of stems and petioles. There was no significant difference in total vitamin A and thiamin contents between three portions. Ascorbic acid content of leaves harvested on the 30th day was the highest, 57mg/100g, and decreased to 18mg/100g in the leaves harvested on the 40th day. Marked increase in crude fiber and vitamin A content of leaves was observed in late harvest may be due to the maturation. The results of nutrient composition analysis suggest that the leaves of hydroponic water dropwort is important in ascorbic acid and ash. It is recommended that shorter blanching time and addition of 0.5% NaCl to the blanching water are better for higher ascorbic acid retention of hydroponic water dropwort. In conclusion, as hydroponic water dropwort has high content in ash, calcium, vitamin and free sugar with alkalinity, leaves as well as stems and petioles can be recommonded as a vegetable of high nutritional quality.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.354-366
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• 2021

Limited data about the effects of various factors on forage quality and β-carotene content of rye produced in Korea are available, so this study investigated the effects of two preservation methods. Samples were collected from rye harvested every 5 days between April 25 and May 31, and comparisons were done among rye silage wilted for different periods of time and hay of three growth stages of rye. For the silage, dry matter (DM), acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents increased with advanced maturity of rye, whereas crude protein, in vitro dry matter digestibility (IVDMD), total digestible nutrients (TDN), relative feed value (RFV), and DM loss decreased (p < 0.0001). Wilting increased the DM content and pH value significantly (p < 0.0001). Silage harvested at the heading stage had the lowest pH value (4.45), propionic acid (0.83 g/kg DM), butyric acid (0 g/kg DM), and fungi and yeast populations (3.70 Log CFU/g of fresh matter [FM]); conversely, it had the highest lactic acid (9.7 g/kg DM), lactic acid bacteria (LAB) (6.87 Log CFU/g of FM), total microorganisms (TM) (7.33 Log CFU/g of FM), and Flieg's score (70) (p < 0.0001). Wilting elevated LAB and TM populations, but it had no consistent effect on other fermentation products. Both delayed harvest and prolonged wilting decreased β-carotene content. Rye silage harvested around May 9 (heading stage) with 24 h of wilting was preferred for highland, Pyeongchang. For rye hay, advanced maturity decreased DM loss, IVDMD, TDN, and RFV, but it increased DM, ADF, and NDF significantly (p < 0.05). β-carotene was decreased by delay of hay-making. Consequently, to attain lower DM loss and higher hay quality, the harvest date of May 9 (heading stage) is recommended.

• Food Science and Preservation
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• v.30 no.2
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• pp.205-223
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• 2023

Fresh mushrooms are vulnerable to browning and tissue changes after harvest. This study monitored the external appearance, physicochemical quality indicators, and nutritional and functional components of a white beech mushroom (Hypsizygus marmoreus) variety (EG2020) newly developed in Korea during cold storage for up to 42 days. Two existing varieties of white H. marmoreus, namely H6 from Korea and HKT from Japan, were used for comparison. The mechanical texture of EG2020 was superior to H6 and HKT due to the increasing hardness of the pileus with time. Browning, in terms of the total color difference during storage, was found to be the most severe in HKT. In terms of composition, EG2020 had the highest total free sugar content, a large amount of organic acids, and higher sugar content than H6 and HKT. EG2020 also contained the largest amount of 𝛽-glucan, and its amount increased during storage. In sensory evaluation, EG2020 received higher scores than HKT in flavor, taste, appearance, and texture. Therefore, the EG2020 variety is more stable than HKT during storage and distribution.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.92-99
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• 2014

The crop growing conditions make accurate predictions of yield ahead of harvest time difficult. Such predictions are needed by the government to estimate, ahead of time, the amount of crop required to be imported to meet the expected domestic shortfall. Corn and soybean especially are widely cultivated throughout the world and a staple food in many regions of the world. On the other hand, the CASA (Carnegie-Ames-Stanford Approach) model is a process-based model to estimate the land plant NPP (Net Primary Productivity) based on the plant growing mechanism. In this paper, therefore, a methodology for the estimation of corn/soybean yield ahead of harvest time is developed specifically for the growing conditions particular to Iowa and Illinois. The method is based on CASA model using MODIS data, and uses Net Primary Productivity (NPP) to predict corn/soybean yield. As a result, NPP at DOY 217 (in Illinois) and DOY 241 (in Iowa) tend to have high correlation with corn/soybean yields. The corn/soybean yields of Iowa in 2013 was estimated to be 11.24/3.55 ton/ha and Illinois was estimated to be 10.09/3.06 ton/ha. Errors were 6.06/17.58% and -10.64/-7.07%, respectively, compared with the yield forecast of the USDA. Crop yield distributions in 2013 were presented to show spatial variability in the state. This leads to the conclusion that NPP changes in the crop field were well reflected crop yield in this study.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.445-451
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• 2013

We researched nitrogen and green manure yield of crotalaria by seeding rate; 50, 60, 70, 80, 90 kg $ha^{-1}$ in upland soil to find out crotalaria's optimal seeding rate. Crotalaria's plant height and number of leaves increased when the harvest time was later regardless of its seeding rate. Its nitrogen content of above-ground part was 19.8 g $ha^{-1}$, and C/N ratio was 22.5. The highest nitrogen content (50.3 g $ha^{-1}$) was found in flowers part, followed by its leaves, roots and stems. The green manure yields of crotalaria increased when the harvest time was later. The green manure yield of crotalaria was biggest in 50kg $ha^{-1}$ which was low in seeding rate. It tended to decrease when the seeding rate was higher, and the nitrogen yield had the same tendency. Therefore, the appropriate seeding rate was 50kg $ha^{-1}$ and the time for application to soil was considered to be the flowering stage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.376-380
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• 2016

This experiment was carried out to investigate the effect of harvesting time of Italian ryegrass (Lolium multiflorum Lam; IRG) in spring on dry matter (DM) yield. IRG cultivars 'Kowinearly' and 'Greenfarm' were seeded at 50 kg/ha and grown on rice paddy fields. There was no difference in growth characteristics between both varieties before winter. However, cold tolerance of Kowinearly was higher than that of Greenfarm, as demonstrated by post-wintering growth characteristics. The heading date of both varieties was affected by the spring weather. The IRG was harvested three times at 5-day intervals beginning from 9 May. The DM yield of Greenfarm was 6,306; 7,335; and 8,109 kg/ha, and that of Kowinearly was 7,498; 9,196; and 10,449 kg/ha at the three consecutive harvests. The delay of the harvesting time for 5 and 10 days increased the DM yield of Greenfarm by 16% and 29% and that of Kowinearly by 23% and 39%, respectively, compared to the yield at first harvest (p < 0.05). Therefore, IRG harvest later than early to mid-May is expected to increase productivity. The feed values of Greenfarm were: 12.2% of crude protein (CP), 34.5% of acid detergent fiber (ADF), 57.7% of neutral detergent fiber (NDF), 61.6% of total digestible nutrients (TDN), and 72.3% of in vitro DM digestibility (IVDMD). For Kowinearly, these values were 16.4% of CP, 30.4% of ADF, 52.7% of NDF, 64.9% of TDN and 79.0% of IVDMD.