• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.77-77
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• 2018

천마(Gastrodia elata)는 연중생산을 위해 실내시설 재배 시 생육모델을 구죽하고, 생육단계에 따른 온도, 수분, $CO_2$ 등 환경 조건 설정이 필요하다. 본 연구는 천마의 생육단계 중 괴경형성기와 괴경비대기의 수분함량을 설정하여 최적의 환경조건을 찾기 위해 수행하였다. 먼저 괴경형성기 수분함량 공급은 괴경형성기에 -20kPa, -30kPa, -40kPa로 처리하여 120일간 배양한 뒤, 괴경비대기를 -40kPa로 고정하여 60일간 배양하였다. 반면, 괴경비대기 수분함량 공급은 괴경형성기를 -30kPa로 고정하여 120일간 배양한 뒤 괴경비대기에 -20kPa, -30kPa, -40kPa, -50kPa로 처리하여 60일간 배양하였다. Tensiometer(토양수분장력계)기를 설치하여 수분을 공급하였고, FDR센서 (UbiMas, CoCo sensor, Frequency domain reflectometry type)를 배양토의 깊이 5 cm와 15 cm에 2개를 설치하여 평균값으로 수분함량을 측정하였으며, 전체수량, 성마율, 종마율 등을 조사하였다. FDR센서로 수분함량을 측정한 결과, -20 kPa은 43.3%, -30 kPa은 34.7%, -40 kPa은 29.8%, -50 kPa은 25.3%로 측정되었다. 괴경형성기 수분함량 처리 후 수확기의 상자 당 전체수량은 -30 kPa일 때 985 g으로 가장 많았고, -40 kPa일 때 912 g, -20 kPa일 때 703 g으로 처리간의 유의적인 차이를 보였다. 성마율은 수분함량처리별 각각 25, 34, 30% 이었고, 종마율은 수분함량처리별 각각 53, 73, 65%로 나타났다. 따라서 -30 kPa 처리구가 다른 처리구에 비해 전체수량, 성마율, 종마율 등이 유의적으로 우수하였다. 괴경비대기 수분 함량 처리 후 수확기의 상자 당 전체수량은 -40 kPa일 때 992 g으로 가장 많았고, -50 kPa일 때 955 g, -30 kPa일 때 903 g, -20 kPa일 때 686 g 순으로 나타났다. -30 kPa에서 -50 kPa 사이에서는 전체 수량의 유의성 차이는 없었다. 성마율은 수분함량처리별 각각 20, 30, 35, 33%이었고, 종마율은 수분함량처리별 각각 45, 65, 75, 68%로 나타났다. 따라서 -40 kPa 처리구가 다른 처리구에 비해 전체수량, 성마율, 종마율 등이 유의적으로 우수하였다. 반면 -20 kPa 처리구는 과도한 수분으로 천마가 오히려 부패될 수 있는 환경조건이 조성됨에 따라 성마율, 종마율 등 전체적인 수량 감소에 영향을 미친 것으로 판단되었다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.2
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• pp.74-87
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• 2016

Potato phenology, growth, and yield are projected to be highly affected by global warming in the future. The objective of this study was to examine the responses of potato growth and yield to environmental elements like temperature, solar radiation, and daylength. Planting date experiments under open field condition were conducted using three cultivars differing in maturity group (Irish Cobbler and Superior as early; Atlantic as mid-late maturing) at eight different planting dates. In addition, elevated temperature experiment was conducted in four plastic houses controlled to target temperatures of ambient temperature (AT), $AT+1.5^{\circ}C$, $AT+3^{\circ}C$, and $AT+5^{\circ}C$ using cv. Superior. Tuber initiation onset was found to be hastened curve-linearly with increasing temperature, showing optimum temperature around $22-24^{\circ}C$, while delayed by longer photoperiod and lower solar radiation in Superior and Atlantic. In the planting date experiments where the average temperature is near optimal and solar radiation, rainfall, pest, and disease are not limiting factor for tuber yield, the most important determinant was growth duration, which is limited by the beginning of rainy season in summer and frost in the late fall. Yield tended to increase along with delayed tuber initiation. Within the optimum temperature range ($17^{\circ}-22^{\circ}C$), larger diurnal range of temperature increased the tuber yield. In an elevated temperature treatment of $AT+5.0^{\circ}C$, plants failed to form tubers as affected by high temperature, low irradiance, and long daylength. Tuber number at early growth stage was reduced by higher temperature, resulting in the decrease of assimilates allocated to tuber and the reduction of average tuber weight. Stem growth was enhanced by elevated temperature at the expense of tuber growth. Consequently, tuber yield decreased with elevated temperature above ambient and drop to almost nil at $AT+5.0^{\circ}C$.

• Journal of Mushroom
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• v.16 no.2
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• pp.90-95
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• 2018

This study was carried out to investigate the optimum temperature and the cultivation period according to the different growth stages of Gastrodia elata (G. elata). The growth period for the indoor cultivation of G. elata is divided into four stages that require specific temperatures during the enlargement of the tuber. The optimum temperatures and cultivation periods during the growth stages of G. elata were observed to be $20^{\circ}C$ for 30 days during the mycelial growth stage (MGS), $25^{\circ}C$ for 120 days during the tuber formation stage (TFS), $6-24^{\circ}C$ for 60 days during the tuber enlargement stage (TES), and $5^{\circ}C$ for 30 days during the dormant stage (DS). The total cultivation period was shortened by 120 days in the indoor cultivation facilities by reduction of 30 days from the mycelial growth stage, addition of 30 days to the tuber formation stage, and reduction of 120 days from the dormancy stage as compared to the outdoor field cultivation. These results provide a basis for a growth model that permits year-round cultivation of G. elata.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.316-328
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• 2021

In this study, the leaf Na content prediction model for spring potato was established using 400-1000 nm hyperspectral sensor to develop the multispectral sensor for the salinity monitoring in reclaimed land. The irrigation conditions were standard, drought, and salinity (2, 4, 8 dS/m), and the irrigation amount was calculated based on the amount of evaporation. The leaves' Na contents were measured 1st and 2nd weeks after starting irrigation in the vegetative, tuber formative, and tuber growing periods, respectively. The reflectance of the leaves was converted from 5 nm to 10 nm, 25 nm, and 50 nm of FWHM (full width at half maximum) based on the 10 nm wavelength intervals. Using the variance importance in projections of partial least square regression(PLSR-VIP), ten band ratios were selected as the variables to predict salinity damage levels with Na content of spring potato leaves. The MLR(Multiple linear regression) models were estimated by removing the band ratios one by one in the order of the lowest weight among the ten band ratios. The performance of models was compared by not only R2, MAPE but also the number of band ratios, optimal FWHM to develop the compact multispectral sensor. It was an advantage to use 25 nm of FWHM to predict the amount of Na in leaves for spring potatoes during the 1st and 2nd weeks vegetative and tuber formative periods and 2 weeks tuber growing periods. The selected bandpass filters were 15 bands and mainly in red and red-edge regions such as 430/440, 490/500, 500/510, 550/560, 570/580, 590/600, 640/650, 650/660, 670/680, 680/690, 690/700, 700/710, 710/720, 720/730, 730/740 nm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.317-326
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• 2019

Salinity which is often detected on reclaimed land is a major detrimental factor to crop growth. It would be advantageous to develop an approach for assessment of salinity and drought damages using a non-destructive method in a large landfills area. The objective of this study was to examine applicability of the decision tree classifier using imagery for classifying for spring potatoes (Solanum tuberosum) damaged by salinity or drought at vegetation growth stages. We focused on comparing the accuracies of OA (Overall accuracy) and KC (Kappa coefficient) between the simple reflectance and the band ratios minimizing the effect on the light unevenness. Spectral merging based on the commercial band width with full width at half maximum (FWHM) such as 10 nm, 25 nm, and 50 nm was also considered to invent the multispectral image sensor. In the case of the classification based on original simple reflectance with 5 nm of FWHM, the selected bands ranged from 3-13 bands with the accuracy of less than 66.7% of OA and 40.8% of KC in all FWHMs. The maximum values of OA and KC values were 78.7% and 57.7%, respectively, with 10 nm of FWHM to classify salinity and drought damages of spring potato. When the classifier was built based on the band ratios, the accuracy was more than 95% of OA and KC regardless of growth stages and FWHMs. If the multispectral image sensor is made with the six bands (the ratios of three bands) with 10 nm of FWHM, it is possible to classify the damaged spring potato by salinity or drought using the reflectance of images with 91.3% of OA and 85.0% of KC.

• Research in Plant Disease
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• v.18 no.2
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• pp.117-122
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• 2012

In 2006, the effect of soil pH adjustment on control of common scab of potato caused by Streptomyces spp. was evaluated in the field. Soil with an original pH 5.7 was treated with sulfur of 42 kg/10a and calcium hydroxide of 81.6 kg/10a and 184.5 kg/10a to adjust pH 5.0, 6.0 and 6.5, respectively. Additionally, the effect of gypsum (522 kg/10a) on soil pH and disease severity was examined. The soil pH of sulfur treatment plot was continuously declined from 5.13 at tuber initiation time to 5.01 at harvest. The disease severity of sulfur treatment plot was relatively low (22.8%) and the marketable yield of that was high (90.5%). By contrast, the soil pHs treated with calcium hydroxide (81.6 kg/10a and 184.5 kg/10a) were increased (pH 6.06 and 6.49, respectively) at harvest. In addition, calcium hydroxide treatment plots showed higher disease severities (51.0% and 61.1%), and lower marketable yields (55.7% and 37.0%). Meanwhile, the soil pH of gypsum treatment plot was not changed until harvest, and the disease severity and the marketable yield were not significantly different from those of control. The effect of crop rotation was also evaluated with four crops such as welsh onion, soybean, corn and Chinese cabbage. These crops were planted in the infested field from 2005 to 2007, and potatoes were planted in the same field in 2008. The disease severities of potatoes produced after rotations with welsh onion, soybean, corn and Chinese cabbage for 3 years were 13.1%, 16.7%, 28.9% and 30.2%, respectively. However, the disease severity of 73.1% was shown in continuous cropping of potato for 3 years. In addition, similar effects were exhibited in the marketable yield. These results demonstrate that the adjustment of soil pH and crop rotation might be very useful tools to control common scab of potato.