• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.211-215
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• 2006

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.209-211
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• 1998

Black dot root rot occurred severely in greenhouse tomatoes in jangseong area of Korea in April, 1996. The causal fungus of the disease was identified as Colletotrichum coccodes based on the morphological and cultural characteristics. Pathogenicity tests revealed that isolates of the fungus were responsible for the disease, and two cultivars of cherry tomato were less susceptible to the disease than other cultivars of tomato and cherry tomato tested.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.165-165
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• 2005

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.931-939
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• 2019

Biochar is a solid carbon material made by pyrolyzing a biomass under limited oxygen conditions. Biochar has been reported to confer various benefits, such as increased soil productivity, pollutant absorption, and reduced greenhouse gas. In this study, oak pyrolyzed at 600℃ for 3 hours was either powdered or pelleted. Each of the biochar types was added to the soil at a rate of 2%. The control did not receive any biochar while a combination of the biochar and NPK treatment (biochar 2% + NPK) was also included. The cherry tomatoes were grown in greenhouse pots for 50 days to compare the growth characteristics of the different treatments. The cherry tomato with the powdered biochar 2% + NPK treatment had the heaviest plant fresh shoot weight of 276.4 g and the highest chlorophyll content of 59.3 SPAD. The control had the lightest plant fresh shoot weight of 44.2 g and a chlorophyll content of 26.5 SPAD. Both forms of biochar affected the chemical properties of the soil, increased the pH, electrical conductivity, available phosphate, total carbon and total nitrogen and positively influenced the cherry tomato growth and productivity. From the above results, therefore, both biochar forms are suited for use as soil amendments.

• Research in Plant Disease
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• v.18 no.4
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• pp.396-398
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• 2012

Pink mold rot of tomato occurred very severly on tomato farm in Paju, Gyounggi Province, Korea, in July 2005. The infected fruits were dropped and abandoned and the symptoms were similar to calcium deficient tomatoes. But symptom was a slight water-soaked area on or near the blossom end of the fruit and firm greyish-brown lesions were most found at the blossom-end of affected fruits. lesions caused by the pink mold fungus possess a water soaked margin and rise to characteristic orange-pink spores. Also when the diseased tomato was cut, the inside of tomatoes showed completely rotted with pink mold. The causal fungus was identified as Trichothecium roseum based on mycological characteristics. This is the first report of T. roseum infecting greenhouse tomatoes in Korea.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.743-752
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• 2020

The purpose of this study was to estimate the economic evaluation of a smart farm investment for tomatoes and strawberries. In addition, the potential adoption rate of the smart farm was derived for different scenarios. This study analyzed the economic evaluation with the net present value (NPV) method and estimated the adoption potential of the smart farm with the trade-off analysis, minimum data (TOA-MD) model. The results were as follows: The analysis of the net present value shows that the smart farm investment for the two crops are economically feasible, and the minimum prices for the tomatoes and strawberries should be 1,179 and 3,797 won/kg to secure a sufficient economic feasibility for the smart farm investment. Next, the analysis of the potential adoption rates for smart farms through the TOA-MD model showed that when the support ratio for the adoption of a smart farm system was 50% and the price increase rates were, respectively, - 5, 2.5, 0, 2.5, and 5%, the conversion rates for tomato farms to switch to smart farms were 0.97, 1.78, 3.05, 4.91, and 7.47%, while the ratios of the strawberry farms to switch to smart farms were 0.12, 0.29, 0.65, 1.33, and 2.53%, respectively. This study has some known limitations, but it provides useful information on decision making about smart farm adoption and can contribute to government policies on smart farms.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.456-463
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• 2020

This research was conducted to examine the changes in yield and difference in growth, using rootstocks in tomatoes as the growth indicators. Seedlings of tomato 'Gama', were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. The non-grafted and grafted plants were grown in hydroponics for long-duration cultivation under plastic greenhouse conditions. The total yield of grafted tomato 'Powerguard' and non-grafted tomato 'Gama' were 8,428 g and 7,645 g, respectively. The flowering position of grafted plants 'B.blocking' and non-grafted plants at the latter period were 17.58 cm and 14.92 cm, respectively. The results showed that the yield and the balance of the plant were improved until the end of the harvest by grafting. The difference in yield between non-grafted and grafted tomatoes was evident in the 19th cluster, 236 days after planting. Therefore using rootstocks could be advantageous for long-duration cultivation in tomatoes.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.7-12
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• 2013

Environmental measurements in the many different types of horticultural farms were carried out to evaluate the ventilation performance for multi-span plastic greenhouses according to the eaves height, the number of spans, the existence of side wall vents and the position of roof vents. Hydroponic tomatoes were being cultivated in all experimental greenhouses, and ventilation rates of the greenhouses were analyzed by the heat balance method. It showed that the ventilation rate in the greenhouse with 4 m eaves height increased about 22% compared to the greenhouse with 2 m eaves height. The ventilation rate in the greenhouse with 9 spans decreased about 17% compared to the greenhouse with 5 spans. In the greenhouse with 9 spans, if there were no side wall vents, the ventilation rate showed about a third of the case that side wall vents were open. Overall, as the eaves height was higher and the number of spans was smaller in multi-span greenhouses, the natural ventilation performance was better. And the ventilation performance was best in the greenhouse which the eaves height was high and the position of roof vents was ridge, not gutter. Therefore, in order to maximize the natural ventilation performance, multi-span plastic greenhouses need to improve their structures such as that make the eaves height higher, place the roof vents on the ridge, install the side wall vents as much as possible, and the number of spans is limited to about 10 spans.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.181-189
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• 2023

Hydrogen has gained attention as an environmentally friendly energy source among various renewable options, however, its application in agriculture remains limited. This study aims to apply the hydrogen fuel cell triple heat-combining system, originally not designed for greenhouses, to greenhouses in order to save energy and reduce greenhouse gas emissions. This system can produce heating, cooling, and electricity from hydrogen while recovering waste heat. To implement a hydrogen fuel cell triple heat-combining system in a greenhouse, it is crucial to evaluate the greenhouse's heating and cooling load. Accurate analysis of these loads requires considering factors such as greenhouse configuration, existing heating and cooling systems, and specific crop types being cultivated. Consequently, this study aimed to estimate the cooling and heating load using building energy simulation (BES). This study collected and analyzed meteorological data from 2012 to 2021 for semi-enclosed greenhouses cultivating tomatoes in Jeonju City. The covering material and framework were modeled based on the greenhouse design, and crop energy and soil energy were taken into account. To verify the effectiveness of the building energy simulation, we conducted analyses with and without crops, as well as static and dynamic energy analyses. Furthermore, we calculated the average maximum heating capacity of 449,578 kJ·h^-1 and the average cooling capacity of 431,187 kJ·h^-1 from the monthly maximum cooling and heating load analyses.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1627-1635
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• 2024

The inhabitation and parasitism of root-knot nematodes (RKNs) can be difficult to control, as its symptoms can be easily confused with other plant diseases; hence, identifying and controlling the occurrence of RKNs in plants remains an ongoing challenge. Moreover, there are only a few biological agents for controlling these harmful nematodes. In this study, Xenorhabdus sp. SCG isolated from entomopathogenic nematodes of genus Steinernema was evaluated for nematicidal effects under in vitro and greenhouse conditions. The cell-free filtrates of strain SCG showed nematicidal activity against Meloidogyne species J2s, with mortalities of > 88% at a final concentration of 10%, as well as significant nematicidal activity against the three other genera of plant-parasitic nematodes in a dose-dependent manner. Thymine was isolated as active compounds by assay-guided fractionation and showed high nematicidal activity against M. incognita. Greenhouse experiments suggested that cell-free filtrates of strain SCG efficiently controlled the nematode population in M. incognita-infested tomatoes (Solanum lycopersicum L., cv. Rutgers). In addition, a significant increase in host plant growth was observed after 45 days of treatment. To our knowledge, this is the first to demonstrate the nematicidal activity spectrum of isolated Xenorhabdus species and their application to S. lycopersicum L., cv. Rutgers under greenhouse conditions. Xenorhabdus sp. SCG could be a promising biological nematicidal agent with plant growth-enhancing properties.