• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.135-139
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• 1995

In order to determine the optimum planting density of Perilla frutescens which is suitable for the southern part of Korea, agronomic characters, yield of fresh stem, leaf and seed, and yield components were investigated grown in 1985 and 1986 at Mokpo Branch Station of Crop Experiment Station. The heading date was Aug. $14{\sim}15$ and the blooming period was Aug. $19{\sim}21$ regardless of the difference of plant density, but the longest stem length was 135cm in the plant density of $70{\time}40cm$ and the stem length in the plant density of $80{\time}40cm$ was 134cm. The quantity of fresh weight of stem and leaf and fresh weight of seed was high as 531kg/l0a in the plant density of $80{\time}40cm$. The positive correlation such as $0.7315^*,\;0.9024^{**}\;and\;0.7425^*$ were found between stem length and fresh weight of stem and leaf, stem length and fresh weight of seed, fresh weight of stem and leaf and fresh weight of seed and so high significance was recongnized. In the verification of significance of row spacing, the disperse of the stem length was $55.67^{**}$, that of fresh weight of stem and leaf is $268.50^*$, theat of fresh weight of seed was $16.00^{**}$ and high significance was recognized. In the verification of significance of intrarow spacing, the diperse of stem length was $54.21^{**}$, that of fresh weight of stem and leaf was $2,582.00^{**}$, that of fresh weight of seed was $48.00^{**}$ and then high significance was recognized. Accordingly, the proper plant density of perilla frutescens was 80cm of row $spacing{\time}40cm$ of intrarow spacing.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.398-403
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• 2012

This study was carried out to investigate the effect of irrigation method adopted for reducing nutrient solution drainage on the root zone environment, growth and yield of a tomato crop grown in a rockwool medium. The irrigation control methods used were large quantity irrigation at a long interval controlled by only an integrated solar radiation sensor (standard), medium quantity irrigation at a medium interval (zero drainage 1), and small quantity irrigation at a short interval (zero drainage 2) controlled by both an integrated solar radiation sensor and a zero drainage sensor. The amount of the nutrient solution supplied and the drain percentage per plant of the standard, zero drainage 1, and zero drainage 2 were 1.4, 0.9 and 0.8 L, and 23.8, 8.6 and 3.7%, respectively. The average, minimum, and maximum water contents and EC of the standard, zero drainage 1, and zero drainage 2 were 64.5~88% and $1.5{\sim}3.5dS{\cdot}m^{-2}$, 40.3~76.0% and $2.5{\sim}4.0dS{\cdot}m^{-2}$, and 56.3~69.0% and $2.7{\sim}3.7dS{\cdot}m^{-2}$, respectively. There was no difference in leaf width, number of leaves, and stem diameter among the treatments. However, plant height and leaf length decreased in the zero drainage 1 and 2 treatments as compared to the standard. The fruit marketable yield per 10a in the zero drainage 1 and 2 treatments was about 93 and 88%, respectively, of that in the standard treatment.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.82-86
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• 2015

This study was carried out to develop the silkworm rearing technique in unused mulberry leaves after harvesting mulberry fruit. The growth of Gwasang No. 2 and Suhyang was very good compared to control cultivar Chungil in leaves size and new branch growth, but new branch and leaves of Daeshim was similar or small to control cultivar Chungil. The number of leaves of Gwasang No. 2 and Suhyang was lower than Chungil, but weight of leaves per tree was heavyer than Chungil. Mulberry leaf yield was Gwasang No. 2 521 kg/10a, Suhyang 189 kg/10a, Daeshim 73 kg/10a, Chungil 1,095 kg/10a. Content of mineral element of all three mulberry cultivars leaf for mulberry fruit production was higher than Chungil in N, P, K, Ca etc. Feeding quantity of silkworm of Gwasang No. 2 and Suhyang was much more than Chungil. Feeding quantity was highest at Suhyang in 96 kg/box. Growth duration of silkworm larvae was not different in all four mulberry culivars but weight of silkworms (5th instar 3rd day) was heavy at Gwasang No. 2 (2.07 g/head) and Suhyang (2.11 g/head) compared to control cultivar Chungil (1.92 g/head). Mortality of silkworms was 14.6% (Gwasang No. 2), 13.3% (Suhyang), 13.9% (Daesim), 12.6% (Chungil) and than higher at elder instar stage. The production amount of silkworm (5th instar 3rd day) was 35.4 kg/box (Gwasang No. 2), 36.6 kg/box (Suhyang), 35.0 kg/box (Daeshim), 33.6 kg/ box (Chungil). Amount of possible rearing silkworms was estimated 3.4box/10 a (Gwasang No. 2), 1.3box/10a (Suhyang), 0.5box/10a (Daeshim), 8.7box/10a (Chungil).

• Horticultural Science & Technology
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• v.29 no.4
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• pp.311-316
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• 2011

This study aimed to determine the effect of EC (electrical conductivity) levels of nutrient solution in hydroponic culture on allyl-isothiocyanate (AITC) content within plant tissues, Vitamin C content and physiological responses in wasabi plant (Wasabia japonica M. 'Darma'). The 'Darma' was grown for 5 weeks with a deep flow technique (DFT) system controlled at 5 different EC levels, including 0.5, 1, 2, 3, and $5dS{\cdot}m^{-1}$. In result, the highest total content of AITC showed at EC level 5 and $3dS{\cdot}m^{-1}$ for 1 or 5- week, respectively. The total content of AITC increased about 1.2-1.4 times when the plants were grown in the EC levels between 0.5 and $2dS{\cdot}m^{-1}$, whereas the content decreased about 6 and 56 % in the EC level 3 and $5dS{\cdot}m^{-1}$, respectively. The content of AITC was relatively higher in petiole tissue, about 53 %, taken from 1 week-grown plants when the EC was controlled between 0.5 and $2dS{\cdot}m^{-1}$. Root tissue also had relatively higher content of AITC, about 45.1 %, when the EC was controlled at 3 and $5dS{\cdot}m^{-1}$. However, a 5-fold decrease in the AITC content was found in blade tissue and a 6.8-fold decrease in root when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. There was no significant difference in the vitamin C content in 1-week grown leaf tissues under the different EC level treatments; but, the content increased about 27% in 5-week grown plants at the EC level between 0.5 and $2dS{\cdot}m^{-1}$, compared to the 1 week-grown leaf tissue. Electrolyte leakage of leaf tissue taken from 3-week grown plant was 3-fold higher at the EC level $5dS{\cdot}m^{-1}$, compared to the EC level between 0.5 and $2dS{\cdot}m^{-1}$. Chlorophyll content, photosynthesis rate and transpiration rate were decreased when the EC was controlled at higher than $2dS{\cdot}m^{-1}$. Leaf water content, specific leaf area and growth were decreased when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. All the integrated results in this study suggest that the EC level of nutrient solution should be maintained at lower than $3dS{\cdot}m^{-1}$ in order to improve nutritional value and quantity required for hydroponically grown wasabi as functional vegetable.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.1-34
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• 1974

These experiments pertain to various factors influencing the quantitative characters of cocoon crops in summer and early autumn seasons. Initially, in order to establish the possible ways of the silkworm rearing more than three times a year in Korea, the author attempted to get further information about the various factors affecting the cocoon crop in every silkworm rearing season. The trials were conducted eleven times a year at four places for three years. The field trial was conducted with 19 typical sericultural farmers who had been surveyed. At the same time the author statistically analyzed the various factors in close relation to tile cocoon crop in autumn season. The effect of guidance on 40 sericultural farmers was analyzed, comparing higher level farmers with lower level farmers ; and the author surveyed 758 non-guided farmers near the guided farmers during both spring and autumn seasons. In addition, another trial on the seasonal change of leaf quality was attempted with artificial diets prepared with leaves grown in each season. It was found that related factors to cocoon crops in summer and early autumn seasons appeared to be leaf quality, and temperature for young and grown larvae. A 2$^4$ factorial experiment was designed in summer season, and another design with one more level of varied temperature or hard leaf added to a 24 factorial experiment was conducted in early autumn. The experimental results can be summarized： 1. Study on the cocoon crops in the different rearing seasons 1) It was shown that earlier brushing of silkworm generally produced the most abundant cocoon crop in spring season, and earlier or later than the conventional brushing season, especially earlier brushing was unfavorable for the abundant cocoon crop in autumn season. 2) The cocoon crop was affected by the rearing season, and decreases in order of sire with spring, autumn, late autumn, summer and early autumn seasons. 3) It was Proved that ordinary rearing and branch rearing were possibles 4 times a year ; in the 1st, 3rd, 8th, and 10th brushing season. But the 11th brushing season was more favorable for the most abundant cocoon crop of branch rearing, instead of the 10th brushing season with ordinary rearing. 2. Study on the main factors affecting the cocoon crop in autumn season 1) Accumulated pathogens were a lethal factor leading to a bad cocoon crop through neglect of disinfection of rearing room and instruments. 2) Additional factors leading to a poor cocoon crop were unfavorable for rearing temperature and humidity, dense population, poor choice of moderately ripened leaf, and poor feeding techniques. However, it seemed that there was no relationship between the cocoon crop and management of farm. 3) The percentage of cocoon shell seemed to be mostly affected by leaf quality, and secondarily affected by the accumulation of pathogens. 3. Study on the effect of guidance on rearing techniques 1) The guided farms produced an average yearly yield of 29.0kg of cocoons, which varied from 32.3kg to 25.817g of cocoon yield per box in spring versus autumn, respectively. Those figures indicated an annual average increase of 26% of cocoon yield over yields of non-guided farmers. An increase of 20% of cocoon yield in spring and 35% of cocoon yield in autumn were responsible. 2) On guided farms 77.1 and 83.7% of total cocoon yields in the spring and autumn seasons, respectively, exceeded 3rd grade. This amounted to increases of 14.1 and 11.3% in cocoon yield and quality over those of non-guided farms. 3) The average annual cocoon yield on guided farms was 28.9kg per box, based on a range of 31.2kg to 26.9kg per box in spring and autumn seasons, respectively. This represented an 8% increase in cocoon yield on farms one year after guidance, as opposed to non-guided farms. This yield increase was due to 3 and 16% cocoon yield increases in spring and autumn crops. 4) Guidance had no effect on higher level farms, but was responsible for 19% of the increases in production on lower level farms. 4. Study on the seasonal change of leaf quality 1) In tests with grown larvae, leaves of tile spring crop incorporated in artificial diets produced the best cocoon crop; followed by leaves of the late autumn, summer, autumn, and early autumn crops. 2) The cocoon crop for young larvae as well as for grown larvae varied with the season of leaf used. 5. Study on factors affecting the cocoon crops in summer and early autumn A. Early autumn season 1) Survival rate and cocoon yield were significantly decreased at high rearing temperatures for young larvae 2) Survival rate, cocoon yield, and cocoon quality were adversely affected by high rearing temperatures for grown larvae. Therefore increases of cocoon quantity and improvement of cocoon quality are dependent on maintaining optimum temperatures. 3) Decreases in individual cocoon weight and longer larval periods resulted with feeding of soft leaf and hard leaf to young larvae, but the survival rate, cocoon yield and weight of cocoon shell were not influenced. 4) Cocoon yield and cocoon quality were influenced by feeding of hard leaf to grown larvae, but survival rate was not influenced by the feeding of soft leaf and hard leaf. 5) When grown larvae were inevitably raised at varied temperatures, application of varied temperature in the raising of both young and grown larvae was desirable. Further research concerning this matter must be considered. B. Summer season 1) Cocoon yield and single cocoon weight were decreased at high temperatures for young larvae and survival rate was also affected. 2) Cocoon yield, survival rate. and cocoon quality were considerably decreased at high rearing temperatures for grown larval stages.

• Journal of Life Science
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• v.17 no.11
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• pp.1562-1570
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• 2007

This experiment was conducted to develop fertilizer which promotes plant growth as well as suppressing pathogenic fungi. The fertilizer was made from the mixture of Ju-Back (Korean rice wine cake) and indigenous rhizosphere-bacterium. The main ingredients of Ju-Back were investigated as 6.04% total nitrogen, 42.59% total carbohydrate, 1.01% available phosphate, 73.42% organic matter, 7.72% potassium oxide, 1.35% calcium oxide, 0.53% magnesium oxide. The enzyme activities of Ju-Back were estimated to be 980 units/g for ${\alpha}-amylase$, 300 units/g for glucoamylase, and 1800 units/g for acid pretense. Indigenous rhizosphere bacteria which produced antifungal agent were isolated from soil, and was selected KMU-13 strain which can antagonize against various plant pathogenic fungi (Botrytis cinerea KACC 40573, Sclerotinia sclerotiorum KACC 41065, Fusairum oxysporum KACC 40052, Pythium aphanidermatum KACC 40156, Phytophthora capsici KACC 40476 and Glomerella cingulata KACC 40299). KMU-13 strain was identified as Bacillus subtilis KMU-13 by biochemical and 16s rDNA analysis. The organic fertilizer was made as prototype which was composed 20% Ju-Back, 70% carrier, 9.7% microorganism cultivated solution, 0.3% trace-element. We also investigated an application of fertilizer using Ju-Back for cultivating lettuce (Lactuca sativar) which were grown in three soil conditions that had chemical fertilizer, barnyard manure, lime power, urea, potassium chloride and superphosphate as a control, the whole quantity (80 kg/10a) of posted fertilizer with the control and the half quantity (40 kg/10a) with the control. The growth characteristics were examined and analysed with several weeks interval from 3 weeks to 8 weeks on head length (cm), head width (cm/head), number of leaf and fresh weight (g/plant). The results are summarized as follows. The head width and fresh weight of lettuce were the highest at posted fertilizer 1 (whole quantity) was applied chemical, organic matter (Ju-Back) and carrier. The head length was the highest at posted fertilizer 2 (whole quantity) was applied Ju-Back only.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.254-260
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• 2001

After investigating the developmental process of galls forming on leaf of Zelkova serrata and analyzing the composition and contents of the free amino acids in leaves, galls and haemolymph of aphids, we have come to the following results. Galls induced were mostly distributed on the middle of lower part of leaf to the petiole along vein and most of investigated leaves had one gall only. The growth of galls continued in length and width until Paracolopha morrisoni habitants which transformed into alate adult left the gall. These results also indicate that galls are closely connected with a portion of plant tissues as well as foods and habitats of aphids. 26${\sim}$29 kinds of free amino acids such as proline, alanine and valine and so on, detected in leaves, gall and haemolymph of aphids. The composition of free amino acids were similar in three materials examined, but proline and asparatic acid showed the highest quantity in the leaves and falls, respectively. In case of aphids, alanine was extremely higher as 18.4% of total contents of free amino acids, in 1st instar of fundatrix stage. Total contents of free amino acids in the apteral adult stage of aphid were also increased than in the 1st instar stage. This investigation implies that nitrogen source such as free amino acids is apparently a major growth-material like carbohydrates during development of galls in Zelkova serrata.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.274-274
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• 2017

Temperature has an adverse effect for potential growth and development of Codonopsis lanceolata. The present study examined the responses of growth, yield and mineral element contents under temperature variables in C. lanceolata. Plant height exhibited the best result as being 2 m or higher the open field culture, while the growth is the most restricted in the $30^{\circ}C$. The open field culture also had the largest number of leaves in the early stage of growth. The number of leaves and the height tended to be increased with the temperature of $20^{\circ}C$ and $25^{\circ}C$. The number of branches showed no significance as 32 branches and 26 branches in open field culture and $20^{\circ}C$, respectively. The smallest number of branches was observed in the $30^{\circ}C$ with 15 branches. The leaf color recorded the lowest value in the open field culture unlike the growth above the ground. But all other temperature had no significance with the leaf color value between 50.0 and 52.6. The elevated temperature induced the thinner and shorter diameter and length of root. However, the root diameter was not significantly changed with the change of 1.8 cm and 2.1 cm at open field culture, with $20^{\circ}C$ and $25^{\circ}C$, respectively. The fresh weights of the primary root and lateral roots were 6.3 g and 3.1 g, respectively, at the high temperature. The result showed the thickening of the lowest part under the ground as restricted. The fresh weights of the main root and lateral root were the highest on the open field culture, 20.6 g and 12.2 g, respectively. The contents of cellulose were the highest as 4.41% in the $20^{\circ}C$, followed by the open field culture, $25^{\circ}C$ and $30^{\circ}C$. The higher temperature reduced the contents of cellulose. Moreover, P showed higher ratio in the high temperature while Ca and Mg exhibited the higher ratio towards the low temperature. On the contrary, minor quantity (less than 1%) of mineral nutrients was observed towards all temperature variables.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.304-311
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• 2020

The purpose of this study is to change plant growth according to the light quantity of LED light source and to standardize plant factories technology according to the optimal LED light range. Growth was relatively stable at the 1,400 lx and 1,600 lx intensities, and growth continued with increasing light intensity, but growth slowed down with growth without leaves (Ed- I don't understand). The growth characteristics at 400 lx to 800 lx were sustained to some extent during the experimental period, but the growth of the larvae was maintained until the 7th day and the growth of leaves was not developed. From 1,000 lx to 1,400 lx, brightness, leaf growth and daily growth increased, and the growth cycle exhibited a repeating cycle of growth and slowdown. In addition, 1,600 lx and 1,800 lx showed similar growth to that at 1,400 lx, but leaf growth was high. However, at 1,800 lx, the growth was slightly higher than at 1,400lx and it slowed down over time. In addition, the stronger the light, the higher the temperature around the plant and the greater the dryness of the leaves due to the heat emitted from the light source.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.1029-1035
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• 2005

A 3${\times}$4 factorial field experiment with a complete randomised split-plot design with four replicates was conducted from June 2002 to March 2003 at the experimental farm of the Nong Lam University, Ho Chi Minh City, Vietnam, to determine effects of different harvesting heights (10, 30 and 50 cm above the ground) and cutting intervals (45, 60, 90 and 285 days) on yield of foliage and tubers, and chemical composition of the foliage. Cassava of the variety KM 94 grown in plots of 5 m${\times}$10 m at a planting distance of 30 cm${\times}$50 cm was hand-harvested according to respective treatments, starting 105 days after planting. Foliage from the control treatment (285 days) and all tubers were only harvested at the final harvest 285 days after planting. Dry matter and crude protein foliage yields increased in all treatments compared to the control. Mean foliage dry matter (DM) and crude protein (CP) yields were 4.57, 3.53, 2.49, and 0.64 tonnes DM $ha^{-1}$ and 939, 684, 495 and 123 kg CP $ha^{-1}$ with 45, 60, 90 and 285 day cutting intervals, respectively. At harvesting heights of 10, 30 and 50 cm the DM yields were 4.27, 3.67 and 2.65 tonnes $ha^{-1}$ and the CP yields were 810, 745 and 564 kg $ha^{-1}$, respectively. The leaf DM proportion was high, ranging from 47 to 65%. The proportion of leaf and petiole increased and the stem decreased with increasing harvesting heights and decreasing cutting intervals. Crude protein content in cassava foliage ranged from 17.7 to 22.6% and was affected by harvesting height and cutting interval. The ADF and NDF contents of foliage varied between 22.6 and 30.2%, and 34.2 and 41.2% of DM, respectively. The fresh tuber yield in the control treatment was 34.5 tonnes $ha^{-1}$. Cutting interval and harvesting height had significant negative effects on tuber yield. The most extreme effect was for the frequent foliage harvesting at 10 cm harvesting height, which reduced the tuber yield by 72%, while the 90 day cutting intervals and 50 cm harvesting height only reduced the yield by 7%. The mean fresh tuber yield decreased by 56, 45 and 27% in total when the foliage was harvested at 45, 60 and 90 day cutting intervals, respectively. It is concluded that the clear effects on quantity and quality of foliage and the effect on tuber yield allow alternative foliage harvesting principles depending on the need of fodder for animals, value of tubers and harvesting cost. An initial foliage harvest 105 days after planting and later harvests with 90 days intervals at 50 cm harvesting height increased the foliage DM and CP yield threefold, but showed only marginal negative effect on tuber yield.