• Journal of Bio-Environment Control
• /
• v.16 no.4
• /
• pp.352-357
• /
• 2007

We investigated effects of concentration and duration were investigated in order to promote efficiency of $CO_2$ enrichment in winter. The treatments were conducted with two levels of $CO_2$ concentration, namely 400 ppm, 700 ppm, two levels of duration, 3 h (9:00-12:00), 6 h (9:00-15:00), and control (nonenrichment $CO_2$). Fresh weight of leaves increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Fresh weight of stem and root increased under longer exposure to $CO_2$, but decreased under higher $CO_2$ concentration. Total dry weight increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Combination treatment of longer exposure to $CO_2$ and higher $CO_2$ concentration showed the largest decrease of Root : Shoot dry weight ratio. The $700ppm{\times}6h$ treatment showed higher fruit number and yield than control. The results suggested that the growth under longer exposure to 400 ppm $CO_2$ was better than that under higher $CO_2$ concentration.

• Journal of Bio-Environment Control
• /
• v.17 no.2
• /
• pp.138-142
• /
• 2008

To develop suitable alternative substrates in hydroponics of sweet pepper, changes of water contents of substrates and electric conductivity (EC) of drainage nutrient solution, growth and fruit characteristics according to the kind of coir substrates were investigated compared with rockwool. In all coir substrates compared with rockwool during growing period, water contents were higher, EC of drainage nutrient solution except for fiber 50% were lower, and the coefficient of variation were a little, especially were so in fiber 30% of coir substrates. Plant growth in fiber 30% substrate was better than others but there was no significant difference. Photosynthesis rate and chlorophyll content were best in fiber 50% substrate. Fruit weight was no significant difference, but LID ratio and shape of the fruits were good in fiber 50% substrate and rockwool as which were close to regular square. Therefore, it was estimated that mixed coir substrates with fiber $30{\sim}50%$ are enough in possibility as alternative substrate.

• Journal of Bio-Environment Control
• /
• v.13 no.3
• /
• pp.172-177
• /
• 2004

This experiment was conducted to investigate the effect of daytime temperature on fruit crack-ing in the paprika cv. Fiesta and cv. Jubilee under soil culture experiment of vinyl house for two years from 2003 to 2004. The rate of cracked fruit was higher in cv. Fiesta than cv. Jubilee and was the highest at the high daytime temperature of $34\pm$$1^{\circ}C$. and then rapidly increased after April becomes better weather conditions. The flesh hardness and the rate of flesh dry weight were lower in cv. Fiesta than cv. Jubilee and were the lowest at the high daytime temperature of $34\pm$1$^{\circ}C$. but the thickness of flesh was thicker in cv. Fiesta than cv. Jubilee and was the thinnest at the high daytime temperature of $34\pm$$1^{\circ}C$. Inorganic matter contents of flesh was observed no difference to the cultivars and also the temperature treatments. Root condition in harvesting time was better in cv. Fiesta than cv. Jubilee and was not difference in temperature treatments. Therefore, the rate of cracked fruit showed up a positive correlation to the flesh hardness, flesh dry weight, flesh firmness and root condition, and has not correlation to the flesh thickness and inorganic matter con-tents. In conclusion, differences in cultivar sensitivity and the highest rate of cracked fruit in daytime temperature of $34\pm$$1^{\circ}C$ may be partly due to difference in flesh characteristic and root condition but additional factors may be involved.

• Journal of Bio-Environment Control
• /
• v.17 no.3
• /
• pp.197-203
• /
• 2008

This study was performed to check the structural safety of modified 1-2W Greenhouses to be utilized fur growing Paprika. This type of greenhouse was derived from being remodeled by enhancing the column height of conventional 1-2W type greenhouses. According to the results of structural analysis performed by SAP-2000, there was not significant change in critical snow depth in spite of increasing the column height of 1.2 m by welding. But the critical wind velocities were shown to be $26.0\sim4l.0m/s$, which were $3\sim18%$ lower wind velocities compared with those critical velocities estimated for typical type of 1-2W greenhouse. Under the wind loads, those maximum section forces such as shear force, axial force, and bending moment, together with the deformed frame shape of strained greenhouse, were almost similar in both typical type and modified type. Maximum bending moment of column was found at eave's height of column on windward side. Under the snow loads, those maximum section forces such as shear farce, axial force, and bending moment, together with the deformed frame shape of strained greenhouse, were almost similar in both typical type and modified type. Maximum section forces except axial force was found at eave's height of column. Maximum axial force was found at inner column. Soil bearing capacity together with the total foundation resistance against wind upheaval was found to be consistently safe enough to resist to both wind load and snow load.

• Journal of Biosystems Engineering
• /
• v.36 no.5
• /
• pp.361-368
• /
• 2011

The amount of export of paprika has been increased rapidly in recent years. Therefore, its cultivation area has greatly increased in Korea according to current consumer's attraction. Moreover, it becomes one of the major exporting products while it recorded 53 million dollars, in 2009 resulting in 40% of the total vegetables export. Most of the products are exported to Japan, but it is necessary to prolong the quality preservation periods to export paprika to nations like U.S.A. or EU. However, to encourage an export to many countries, washing and disinfection became more important to deal with longer transportation and medical inspection. The non-chemical use is very important due to stronger regulation of safety to agricultural production. Accordingly, this study was performed to determine the optimum conditions and develop a prototype washing machine, hot water washing of paprika. The results were as follows : The working performance of the prototype was 938 kg/hr, and which was 1.5 times higher than the conventional air gun type washing machine. The operation cost of prototype was 30 won/kg, and 56% of the cost was reduced when compared with air gun type washing machine.

• Korean journal of applied entomology
• /
• v.47 no.4
• /
• pp.429-433
• /
• 2008

On the leaf disc of fruit vegetables (cucumber, sweet pepper, tomato, egg plant, oriental melon), it has been evaluated that the capability of four predatory mites (Amblyseius swirskii Athias-Henriot, Neoseiulus barkeri (Hughes), N. cucumeris (Oudemans), N. californicus (McGregor)) to prey on the eggs of Bemisia tabaci (Gennadius) and to lay own eggs. The most aggressive mite was A. swirskii which had consumed about $9{\sim}12$ eggs in a day. The quantity of eggs consumed by N. barkeri, N. cucumeris and N. californicus was about $6{\sim}9,\;4{\sim}6$ and $1{\sim}4$, respectively. The most productive mite was also A. swirskii which had laid about $1.2{\sim}1.9$ eggs in a day. The others could not lay more than 0.5 eggs in a day.

• Journal of Bio-Environment Control
• /
• v.13 no.3
• /
• pp.167-171
• /
• 2004

Objective of this research was to investigate the effect of irrigation concentration on the growth and fruit quality of sweet pepper(Capsicum annuum L.) in fertigation. The sweet pepper was grown for 210 days with irrigation concentration of EC 0.5, 1.0, 1.5, 2.0, and 3.0 dSㆍ$m^{-1 }$ in fertigation nutrient solution developed by European Vegetable R & D Center, Belgium. The net $CO_2$ assimilation and transpiration rate were the highest in the treatment of 2.0 dSㆍ$m^{-1 }$. The pH in the soil was range of 5.63 ～6.03, the EC increased as the irrigation concentration was getting higher. The SPAD value also increased as the irrigation concentration was getting higher, N, P, K, Mg except Ca were highest in the treatment of EC 2.0 dSㆍ$m^{-1 }$. The growth was good in the treatment of EC 2.0 dSㆍm$m^{-1 }$. The fruit length, width, firmness, and pericarp thickness had no statistical differences among treatments, the fruit fresh weight and dry weight were good in the treatment of EC 2.0 dSㆍ$m^{-1 }$ the yield was good in the treatment of EC 1.5 dSㆍ$m^{-1 }$ and EC 2.0 dSㆍ$m^{-1 }$ The sugar contents was the highest in the treatment of EC 2.0 dSㆍ$m^{-1 }$ with 9.0$^{\circ}$Brix. In conclusion, the optimal irrigation concentration for sweet pepper fertigation was EC 2.0 dSㆍm$^{-1}$ .

• Journal of Bio-Environment Control
• /
• v.13 no.4
• /
• pp.226-232
• /
• 2004

This experiment was conducted to investigate the effect of night and daytime temperatures on growth and yield of paprika 'Fiesta' and 'Jubilee' under soil culture experiment in the vinyl houses during the 2003 and 2004 season. Total fruit yield was greater in 'Fiesta' than 'Jubilee' Marketable yield was not different between two cultivars, due to lower $\%$ marketable fruits in 'Fiesta'. mean Fruit weight was not different between two cultivars. Difference of yield between cultivars was due to fruit number, harves time and root condition. It was caused by cracked fruits to decrease $\%$ marketable fruits. Total yield was greater in nighttime temperature of $18^{\circ}C\;than\;15^{\circ}C$ and marketable yield was considerably greater because of $\%$ marketable fruits was higher. Mean fruit weight was slightly greater in nighttime temperature of $15^{\circ}C\;than\;18^{\circ}C$. Difference of fruit yield in treatments of nighttime temperature was due to fruit number and harvest time. There was not significant difference of yield between daytime temperature of $28^{\circ}C\;and\;31^{\circ}C$, but in $34^{\circ}C$, total and marketable yields were the least and mean fruit weight was the smallest because of decreased $CO_2$ concentration in the house, accerated vegetative growth, and the least chlorophyll content. There were no significant difference in photosynthetic rate, transpiration rate, maximal photochemical efficiency and antioxidant enzyme activities of all temperature treatments in this experiment. However it was clear that a little difference in error range of these results affects the source of crops in any case. It was not acknowledged that compensation effect by high temperature in daytime to the low temperature treatment in nighttime.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1279-1285
• /
• 2011

Korea is currently underway research to estimate carbon footprint in agriculture centered on the RDA (Rural Development Administration). This study was estimated carbon footprint for major 47 crops. In addition, contribution of inorganic chemical fertilizers, main elements for production of crops were analyzed. The carbon footprint of $5.78E+00kg\;CO_2\;eq.\;kg^{-1}$ for citrus fruit in greenhouse was highest, grape in greenhouse, sweet pepper in greenhouse, ginseng, green pepper in greenhouse were followed by $4.61E+00kg\;CO_2\;eq.\;kg^{-1}$, $4.34E+00kg\;CO_2\;eq.\;kg^{-1}$, $4.23E+00kg\;CO_2\;eq.\;kg^{-1}$, $4.04E+00kg\;CO_2\;eq.\;kg^{-1}$ respectively. Next, production phase contribution of inorganic chemical fertilizer to carbon footprint of crop 1 kg were analyzed mean value 1.88%, 9.06% for single fertilizers and complex fertilizers respectively. And use phase accounted for mean value 14.24%. Therefore, to reduce the fertilization of inorganic chemical fertilizer will be reduced $CO_2$ from crop production, also greenhouse gas emissions of agricultural sector will be reduced.

• Korean journal of applied entomology
• /
• v.44 no.3 s.140
• /
• pp.169-175
• /
• 2005

The occurrence of tobacco whiteflies, Bemisia tabaci, in greenhouses was monitored in Korea in 2005. Bemisia tabaci occurred in the rose, sweet pepper, tomato, and cucumber greenhouses of Chungbuk, Chungnam, Gyongnam, and Jeonnam Provinces, but not in Jeonbuk and Gyongbuk Provinces. The biotypes and genetic differentiation of the whiteflies collected in each regions were analyzed by mitochondrial 16S DNA sequences. The 16S DNA sequences of Jincheon (Chungbuk Province) samples were similar to DNA data reported from Japan and Israel which were known as the B biotype. However, the DNA sequences of the Buyeo (Chungnam), Geoje (Gyongnam) and Boseong (Jeonnam) collections, which were 100% homologous showed over 99% similarity to the DNA of Q biotype from Spain and Egyrt. Here we report the first founding of the Q biotype in Korea. It is assumed that, unlike the B biotype reported from Jincheon since 1998, the Q biotype might have been introduced recently from the certain foreign region/country to the greenhouses in those provinces.