• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.204-209
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• 2008

This experiment was conducted to analysis the fruit quality according to training method under low plastic film greenhouse cultivation on sweet pepper (Capsicum annuum cv Special) during summer culture. Training treatments were upright training and inclination training, the fruits were examined and analysed with a month interval from June to November on productivity, fiuit weight, flesh thickness, contents of soluble solids, hardness, shape, and locules. Productivity per month was the highest on June, upright training harvested more than inclination training. Fruit weight of inclination training on June was 232 g which was higher than 26 g of upright training, but upright training was heavier than inclination training after July. Flesh thickness of upright training was thicker than inclination training. Soluble solids content increased with the decrease of temperature, upright training was higher than inclination training. The fruit shape of upright training was not significant according to harvesting date. The number of locules of upright training was $3.27\sim3.34$, and it was not significant according to harvesting date.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.166-172
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• 2018

This study set out to conduct a field survey with smart greenhouse-based farms in seven types to figure out the actual state of smart greenhouses distributed across the nation before selecting a system to implement an optimal greenhouse environment and doing a research on higher productivity based on data related to crop growth, development, and environment. The findings show that the farms were close to an intelligent or advanced smart farm, given the main purposes of leading cases across the smart farm types found in the field. As for the age of farmers, those who were in their forties and sixties accounted for the biggest percentage, but those who were in their fifties or younger ran 21 farms that accounted for approximately 70.0%. The biggest number of farmers had a cultivation career of ten years or less. As for the greenhouse type, the 1-2W type accounted for 50.0%, and the multispan type accounted for 80.0% at 24 farms. As for crops they cultivated, only three farms cultivated flowers with the remaining farms growing only fruit vegetables, of which the tomato and paprika accounted for approximately 63.6%. As for control systems, approximately 77.4% (24 farms) used a domestic control system. As for the control method of a control system, three farms regulated temperature and humidity only with a control panel with the remaining farms adopting a digital control method to combine a panel with a computer. There were total nine environmental factors to measure and control including temperature. While all the surveyed farms measured temperature, the number of farms installing a ventilation or air flow fan or measuring the concentration of carbon dioxide was relatively small. As for a heating system, 46.7% of the farms used an electric boiler. In addition, hot water boilers, heat pumps, and lamp oil boilers were used. As for investment into a control system, there was a difference in the investment scale among the farms from 10 million won to 100 million won. As for difficulties with greenhouse management, the farmers complained about difficulties with using a smart phone and digital control system due to their old age and the utter absence of education and materials about smart greenhouse management. Those difficulties were followed by high fees paid to a consultant and system malfunction in the order.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.299-306
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• 2009

Aflatoxin (AF) and Ochratoxin A (OTA) are carcinogenic and possible carcinogenic mycotoxins respectively produced by Aspergillus spp or Penicillium spp. The study for contamination survey and proposal for reduction of mycotoxin in red pepper were carried out. 192 samples were collected at such various stages and markets as pre/post-harvest stages, internet shopping mall /super-market and small stakeholder mill/geographically indicated company. As only 2 samples were positive for aflatoxin, so contamination rate was 1.04%. In the meanwhile, contamination rate for ochratoxin A was 21.88% and a various amount of OTA was detected in 42 positive samples. 6 samples were found to be contaminated at higher level than $5\;{\mu}gkg^{-1}$ for ochratoxin A, which was established recently as a maximum permissible limit in korea. There was no difference in degree of contamination with regard to cultivation type because any mycotoxin was not found at all in both organically and conventionally grown red pepper. But, there was statistically significant difference in the process of manufacturing. Finished products were OTA-contaminated at a level of $2.32\;{\pm}\;6.54\;{\mu}gkg^{-1}$(mean ${\pm}$ SD), even though OTA was not detected in deep frozen red peppers right after long term storage. And contamination for OTA was a level of $0.33\;{\pm}\;0.91\;{\mu}gkg^{-1}$(mean ${\pm}$ SD) in red paprika powder after uv sterilization, while the contamination for OTA was $2.78\;{\pm}\;4.49\;{\mu}kg^{-1}$(mean ${\pm}$ SD) in non-uv sterilized powder. In addition, our investigation shows that higher OTA contamination occurred in some of famous brand products sold in super-market and domestic products than products collected through on-line shopping or from small stakeholder mills and imported products respectively, however, difference was not statistically significant.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.237-243
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• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.53-59
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• 2014

This study aimed to determine an appropriate cooling timing in the root zone for lowering substrate temperature and its effect on physiological response of sweet pepper (Capsicum annum L. 'Orange glory') grown on coir substrate in summer, from the July 16 to October 15, 2012. Daily temperature of substrate, root activity, leaf water potential, first flowering date, and the number of fruits were measured by circulating cool water through a XL pipe in the root zone during either all day (all-day) or only night time (5 p.m. to 3 a.m.; night) from the July 23 to September 23, 2012. For comparison, no cooling (control) was also applied. Between the $23^{rd}$ of July and $31^{st}$ of August (hot temperature period), daily average temperatures in substrates were $25.6^{\circ}C$, $26.1^{\circ}C$, and $29.1^{\circ}C$ for the all-day and night treatment, and control respectively. About 1.8 to $5^{\circ}C$ lower substrate temperature was observed in both treatments compared to that of control. In sunny day ($600-700 W{\cdot}m^{-2}{\cdot}s^{-1}$), the highest temperature of substrate was measured between 4 p.m. and 5 p.m. under both the all-day and night treatments, whereas it was measured between 7 p.m. and 8 p.m. under the control. Substrate temperatures during the day (6 a.m. to 8 p.m.) and night (8 p.m. to 6 a.m.) differed depending on the treatments. During the day and night, averaged substrate temperature was lower about $3.3^{\circ}C$ and $4.0^{\circ}C$ for the all-day, and $2.1^{\circ}C$ and $3.4^{\circ}C$ for the night treatment, compared to that of control. In the all-day and night treatment, the TD [TD = temperature of (control)] was greater in bottom than that of other regions of the substrate. Between the day and night, no different TD values were observed under the all-day treatment, whereas under the night treatment there was difference with the greatest degree in the bottom of the substrate. During the hot temperature period, total numbers of days when substrate temperature was over $25^{\circ}C$ were 40, 23 and 27 days for the control, all-day, and night treatment, respectively, and the effect of lowering substrate temperature was therefore 42.5% and 32.5% for the all-day and night treatment, respectively, compared to that for the control. Root activity and leaf water potential of plants grown under the all-day treatment were significantly higher than those under the night treatment. The first flowering date in the all-day treatment was similar to that in the night treatment, but 4-5 day faster than in the control. Also, the number of fruits in both treatments was significantly higher than that in the control. However, there was no effect of root zone cooling on eliminating delay in fruiting caused by excessively higher air temperature (> $30^{\circ}C$), although the substrate temperature was reduced $18^{\circ}C$ to $5^{\circ}C$. These results suggest that the method of cooling root zone temperature need to be incorporated into the lowering growing temperature for growth and fruit set of health paprika.