• Horticultural Science & Technology
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• v.35 no.1
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• pp.79-87
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• 2017

We examined the effect of two greenhouse covering materials (glass or solid polycarbonate sheets) on the light environment and growth of tomato and cucumber plants. Spectral analysis showed that polycarbonate sheets entirely blocked radiation in both the UV - B (300 - 320 nm) and UV - A (320 - 400 nm) ranges, whereas glass transmitted UV - A and was only opaque to UV - B. The transmittance of photosynthetically active radiation (400 - 700 nm) and near infrared radiation (700 - 1100 nm) was higher in polycarbonate than glass. Air and soil temperatures were not significantly different between greenhouses covered with either material. The growth of cucumber plants was slightly affected by covering materials, whereas no significant changes in growth parameters were observed for tomato plants. The color parameters of tomato fruits were affected by the cover material, whereas cucumber fruits showed similar coloration in both glass and polycarbonate greenhouses.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.393-401
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• 2009

About 50,000 hives of Bombus terrestris are used for pollination of tomato and other economical crops (fruit vegetables and fruit trees) in Korea. Therefore this study was conducted to find out the effective use of B. terrestris and its economic effect in the major beefsteak-tomato cultivation areas from February to August in 2008. The pollinating activities, rate of bite-mark and lifespan of B. terrestris's hive according to all beefsteak-tomato varieties (Super Momotaro, Zeus42, Mascara and Super Sunroad, 500 $m^2$, $9,600{\sim}12,000$plants) were apparent by regular supplement of pollen ($5{\sim}6g$/3 days) to the hive of B. terrestris. Especially, Super Momotaro and Super Sunroad variety were most distinctive in the effects by regular pollen supplement.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.381-390
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• 2018

This study was conducted to examine the growth characteristics of seedlings of several major fruit vegetables and compare them between plants grown with the conventional plug seedling system (Plug) and those grown with the cylindrical paper pot system (CPP). There were no significant differences in shoot growth characteristics, such as plant height, leaf area, dry weight, and fresh weight, between tomato, cucumber, and watermelon plants grown with the CPP and Plug systems. The total root lengths of tomato and cucumber plants grown with Plug were longer than those grown with CPP at the beginning of seedling growth, and the total root lengths of watermelon grown with Plug were longer than those grown with CPP throughout the whole seedling period. The length of root that separated five steps according to the diameter of the root of tomato did not differ between CPP and Plug, but those of cucumber and watermelon were 20-251% longer with Plug than with CPP for all kinds of roots. The fresh weight of Plug-grown tomato roots was about 30% heavier than that of CPP-grown tomato during the seedling period, but the difference decreased as growth progressed. Finally, there was no difference between plants before and after transplanting. The fresh weights of the Plug-grown plants were about 20-30% heavier than those of CPP-grown ones in terms of the whole seedling. After transplanting to the Wagner pot, the shoot growth of Plug-grown watermelon plants in terms of dry weight was low until 7 days had passed. However, this tendency was reversed from 8 days after transplantation onward. In conclusion, there were no significance differences in the growth of shoots between plants grown with the CPP and Plug systems. However, root development was better with Plug than with CPP.

• KSBB Journal
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• v.25 no.3
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• pp.289-296
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• 2010

Lectins are carbohydrate-binding and a cell-agglutinating proteins, and are concerted with a plants defence mechanism. In particular, chitin-binding lectins in locular fluid of cherry tomato fruit seemed to have a role in defending plants against fungi. The antifungal activity using lectin isolated from locular fluid of cherry tomato fruit was measured in the plant pathogen Cladosporium cucumerinum, Monosporascus cannonballus, Fusarium oxysporum, and Rhizoctonia solani. Amoung the four strains, a potent antifungal activity was detected in Cladosporium cucumerinum and Monosporascus cannonballus, not in Fusarium oxysporum, and Rhizoctonia solani. The molecular weight of this lectin isolated as double protein bands by SDS-PAGE was calculated to be 87 kDa and 47 kDa from the relative mobilities compared with those of reference molecular weight markers. The isolated lectin agglutinated human red blood cells (A, B, AB, O) treated with trypsin, and the most activity was found at B. The optimal temperature of isolated lectin was at $30^{\circ}C$. For the thermal stability, lectin was stable at $20-80^{\circ}C$. The optimal pH of this lectin was at 7.2, and showed complete loss below pH 9.0.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.36-41
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• 1994

The major objective of this study is to develop a method of zone cooling during summer day using heat pump for year- round cultivation. The efficiency of cold water cooling and fog cooling was investigated. In order to prevent the occurrence of blossom - end rot in tomato, cooling was induced together with air flow of the fruit treatment as well as promoting air circulation in the plant treatment was induced. The following results were obtained : 1) The temperature in the cold water cooling district was 1$0^{\circ}C$ lower than greenhouse temperature and the temperature in the fo8 cooling district was about 5$^{\circ}C$ lower than the greenhouse. 2) Regardless of cooling method, the treatment of air flow on fruit did not affect the fruit but prevent blossom-end rot. There was 34.5% occurrence rate of blossom -end rot in non-air flow district of cold water cooling 54.5% in non-air flow district of fog cooling and 78% in fog circulation cooling district. The cooling efficiency using cold water cooling method induced enough cooling at critical temperature for growth and development and the occurrence of blossom -end rot was lower than fog cooling. Fog cooling in culture district with air circulation did not induce and difference in temperature but caused an Increase in humidity resulting in 24% increase in the occurrence of blossom-end rot. Thus the occurrence of blossom-end rot in tomato caused by environmental factors can be attributed more to humidity than to temperature.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.257-265
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• 2011

During 2002-2008 in Korea, 455 extracts from myxobacteria consisting of 318 cellulolytic and 137 bacteriolytic myxobacteria were isolated, which were then screened for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bacteriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens' groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeated six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84-98%, whereas it was only 5-21% after the KYC 3270 treatment. After KYC 3270 treatment of the four fruits, mold control was 79-95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.28-35
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• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.53-68
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• 2006

This experiment was conducted to investigate the effects of diurnal alternation of nutrient solution salinity on growth and fruit quality of tomatoes (Lycoperisicon esculentum cv. 'House momotaro') hydroponically grown in root intercept bag-NFT (RIB-NFT) system. Plant height was the lowest in the high concentration during daytime (6/1 $dS\;m^{-1}$, day/night). Yield was very high in the concentration of 1/1 $dS\;m^{-1}$, it decreased with increasing the concentration of nutrient Yield was higher at low concentration (4/1 $dS\;m^{-1}$) at nighttime compared to the same concentration (4/4 $dS m^{-1}$) at daytime and nighttime, and the reverse (1/4 $dS\;m^{-1}$) was similar to the control (perlite culture). Yield was greatly reduced by higher concentration at daytime than nighttime, and the decrease was alleviated by lower concentration at nighttime. With increasing the concentration of nutrient solution during daytime, sugar content of tomato fruit was increased, but yield was decreased. In the other experiment, tomato plants were hydropoically cultured in NFT system diurnally alternated between Aichi's solution and $Ca(NO_3)_2$ solution. $Ca(NO_3)_2$ solution was supplied for 4 hours from 10:00 to 14:00 at daytime and from 22:00 to 2:00 at nighttime, respectively, and Aichi's solution was supplied for the time except the 4 hours. Ca content of leaves and sugar content of fruit were increased by supplying $Ca(NO_3)_2$ solution at daytime compared to nighttime, but plant growth was greatly suppressed by supplying $Ca(NO_3)_2$ solution with the concentration of 4 $dS\;m^{-1}(4/4^{Ca}\;dS\;m^{-1})$ at nighttime.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.737-741
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• 1999

We surveyed the physiological disorders of fruit vegetables grown in the greenhouse in Kyungbuk province in 1998. Greenhouses used for cultivation were mostly single or multi-span iron pipe houses covered with polyethylene film. Single span greenhouses were used for strawberry, oriental melon and watermelon. Fifty six percent of the surveyed farms was a mono-cropping system for oriental melon and tomato. There were greenhouses used for successive cultivation for 10 years or more for strawberry and oriental melon in Koryeong and Seongju. Varieties of fruit vegetables cultivated were diverse, especially in cucumber and watermelon. In strawberry, malformed fruits were observed most frequently in March and the small fruits at late harvest period. Leaf chlorosis, stunt plants and runner outbreak were also found during the growing season. In tomato, occurrence of malformed fruits was severe from March to May, and occurrence of cracked fruits and blossom- end rot was also severe in October and November. The self topping and abnormal stem in tomato were problem in hydroponic cultures in August and November, respectively. Malformed cucumber fruits, such as curved, club shaped, irregular shaped and narrow necked, occurred at late season. Umbrella-shaped leaf in cucumber in summer were caused by calcium deficiency. Most serious disorders were fermented and malformed fruits occurring from March to May in oriental melon, and cracked fruits occurring from April to May in watermelon. At late growing stage of melons the leaf chlorosis occurred with complex symptoms of leaf disease. Growers had little knowledge on physiological disorders, and also on diagnose and measures to cure the disorders. Most growers pointed out that poor soil environment and temperature management in the greenhouse as the main causes of physiological disorders.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.311-316
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• 2015

This study was performed to ascertain the potential of egg plant for use as a trap plant to attract Bemisia tabaci adults compared to that of tomato. Choice tests were conducted to compare the preference of B. tabaci adults to horseweed, egg-plant, cucumber, and tomato. B. tabaci adults were found to be more sensitive to visual cues than to odor cues, and they preferred the egg-plant and cucumber to horseweed. The attraction rates of the egg-plant and cucumber to B. tabaci adults were 82.3% and 82.5% respectively, compared to that of tomato. Because egg-plants are easier to manage compared to cucumber, we excluded cucumber from subsequent experiment. The attraction rate of egg-plant to B. tabaci adults was >90% when the height of egg-plant was equal or more than that of the tomato plant.