• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.263-266
• /
• 2011

Crop protection strategies in organic horticulture aim to prevent insect pest and plant disease problems through utilization of non-chemical based control means. In order to develop a model for management of plant diseases and insects in organic cucumber cultivation, we compared efficacies between chemical pesticide spraying system and biological control means in semi-forcing and retarding cucumber cultivation during 2005 and 2006. Conventional chemical spray program using various chemical pesticides was applied 5 - 10 days intervals, while two different non-chemical pesticide application programs using two formulated biopesticides Topseed$^{TM}$ and Q-fect$^{TM}$, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 1) and using egg-yolk and cooking oil(EYCO), Bordeaux mixture, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 2) were applied 5 - 7 days intervals during entire cucumber cultivation period. Efficacy of both biocontrol agents programs was effective to comparable to conventional chemical pesitice spray program to control plant diseases such as powdery mildew and downy mildew as well as insect pests such as aphids and thrips which are known as major threats in cucumber organic cultivation. In this study, we established and evaluated an effective and economic crop protection strategy using various biological resources can be used to control plant diseases and pests simultaneously in organic cucumber cultivation field.

• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.223-226
• /
• 2006

This study was conducted to select proper varieties of cucumber by comparing growth and yield in retarding cultivation under hydroponic culture. Number of leaves appeared to be the highest Chungjangoi and the lowest in Heukjinjuoi. Heukjinjuoi showed higher vegetative growth rate. Heukjinjuoi showed the highest number of female flowers while Chungjangoi the lowest. The ratio of female flower was the highest in Heukjinjuoi and the lowest in Chungjangoi. Abortion of female flower appeared to be the highest in Heukjinjuoi and the lowest with 0% in Chungjangoi. There was no significant difference in yield between treatments of removal and not-removal of lateral buds.

• Korean journal of applied entomology
• /
• v.59 no.4
• /
• pp.411-416
• /
• 2020

Whitefly populations found in heated tomato greenhouses were monitored across three locations in Korea (Nonsan and Buyeo, Chungnam Province; Iksan, Jeonbuk Province) from November to May during the 2015 -2018 growing seasons. From May to October, surveys were conducted in Jangsu (Jeonbuk Province), where retarding cultivation was performed. Whitefly populations were classified and quantified by location and year. The dominant species were Trialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius). The species populations were mixed, but the frequency of occurrece of B. tabaci was higher than that of T. vaporariorum. Although whitefly populations started to increase in late March, they sharply increased in May and the highest population density was observed at the end of the harvest season. Therefore, the management of greenhouse tomato whiteflies through monitoring should begin in early March. In the case of retarding cultivation, the management of whitefly populations should be implemented in June, before the density of whitefly populations increases.

• Korean Journal of Breeding Science
• /
• v.41 no.2
• /
• pp.141-144
• /
• 2009

A new spray chrysanthemum 'Pink Berry' was released by National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Korea in 2007. A cross was made in 2004 between 'Lineker Salmon', a spray cultivar with salmon petals, and 'Baeksokuk', a spray cultivar with white petals. Trials were conducted from 2005 to 2007 for evaluation and selection of this cultivar, including shade cultivation in summer and retarding cultivation in autumn. The natural flowering time of 'Pink Berry' is late October, but year-round flowering is possible by photo-periodic control. The cultivar has single type flowers with pink petals and a green flower center. It shows long vase life of 22 days and resistance to white rust. The diameter of flower is 52.0 mm. The numbers of flowers per stem and petals per flower are 15.5 and 29.5, respectively. Days to flowering under the short day treatment is about 56 in autumn seasons.

• Journal of Bio-Environment Control
• /
• v.10 no.4
• /
• pp.213-218
• /
• 2001

In 2000, domestic protected cultivation area was about 52,189 ha including 13,621 ha of heating greenhouses. Recently, heating cost accounts for 25 to 30% of total production cost which has been increased due to the rise of oil price, while the heating cost was about 15% in other advanced countries. To reduce the heating energy cost, the study of minimizing the heating space of greenhouse have been conducted from 1998 to 1999. The system was developed to control the heating space according to crop growth by moving horizontal curtain up and down. Installation of the heating space-control curtain in greenhouse decreased heating capacity to 264 m$^3$compared to 661.5 m$^3$in the traditional curtain, and consumpted fuel was saved about 56% point in semiforcing culture and 28% point in retarding culture of pepper. In addition, uniform distribution of air temperature and relative humidity in greenhouse environment resulted in earlier flowering and higher yields in hot pepper.

• Research in Plant Disease
• /
• v.20 no.4
• /
• pp.303-306
• /
• 2014

Tomato yellow leaf curl virus (TYLCV) disease survey of tomato plants cultivated at Youngam, Changseong and Hwasun in Jeonnam Province was conducted in 2012 to 2013. To detect TYLCV in the field, PCR assay was performed using genomic DNAs extracted from tomato samples. According to cropping pattern, 23 and 59.4% of TYLCV infections were shown in semi-forcing and retarding cropping systems, respectively, and the frequencies of diseased plants were 0.4 and and 13.1% in the two cropping systems, respectively. Especially, TYLCV incidences in the susceptible varieties were 24.3 and 83.0% in semi-forcing and retarding cropping systems, respectively. Resistant varieties showed 9.1% infection in retarding cropping system but did not in semi-forcing cropping system. Also, TYLCV was occurred on early June after transplanting on April and at approximate 20 days after transplanting on August or September.

• Korean Journal of Breeding Science
• /
• v.42 no.6
• /
• pp.606-610
• /
• 2010

A new cultivars Dendranthema grandiflourm 'Dream Moon' was developed at Gyeonggi-do Agricultural Research and Extension Services (GARES), Korea in 2008. The cultivar 'Dream Moon' was derived from a cross between 'Patra', a spray cultivar with yellow single type, and 'Sei-rosa', a spray cultivar with pink single type in 2005. The cultivar has single type flowers with pink petals. Trial evaluation was conducted from 2006 to 2008 for a shading cultivation in summer and a retarding cultivation in spring. The flowering time of 'Dream Moon' is late October, and year-round flowering is possible by shade or light treatment. The diameter of flower is 56.0 mm. Numbers of flowers per stem and petals per flower are 16.4 and 24.6, respectively. After investing of specific characters from 2006 to 2008, it was finally selected and named 'Dream Moon'. It has resistance to white rust and the vase life is about 20.7days in autumn season.

• Korean Journal of Agricultural Science
• /
• v.49 no.3
• /
• pp.629-641
• /
• 2022

This research was conducted to secure fundamental data for development of a recirculating hydroponic system. To achieve this, Lycopersicum esculentum var. 'Dafnis' and 'TY Tiny' were grown with Yamazaki hydroponic solution and the inorganic element concentrations of plant leaves and nutrient solution of supplied and drained were analyzed periodically. The T-N and P contents in both varieties of tomato leaves showed gradual decreasing tendencies with the passage of time. The 'TY Tiny' tomato had higher contents of those two nutrients than 'Dafnis' tomato in the late stage. The K content of 'Dafnis' tomato was high in the early growth stage, but low in the late stage. However, that of 'TY Tiny' tomatoes rose in the late stage. The Ca content gradually increased in both varieties of tomato in the latter stages. The EC of the drained nutrient solution in both varieties of tomato showed increasing tendencies as time had passed, but the pH was get lowered in the drained solution. The concentrations of NO₃-N, K, Ca, Mg, Na, Fe, and B, except PO₄-P in the drained nutrient solution were generally higher than those in the supplied solution, especially in the period of October through December. The above results can be used for controlling of nutrient concentrations in the recirculated hydroponic cultivation of tomato.

• Mycobiology
• /
• v.30 no.4
• /
• pp.233-239
• /
• 2002

The main aim of this study is to evaluate the efficiency of two biologically active compounds(Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F. oxysporum, F. solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The $K^+$ efflux and the leakage of UV absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of $K^+$ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions(chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.1
• /
• pp.48-51
• /
• 2009

A new spray chrysanthemum(Dendranthema grandiflorum Ramat.) cultivar 'Yes Arang' was originated from a cross between 'NOA' and 'SP03-05-04'. This cultivar was tested on the characteristics from 2005 to 2007 for the evaluation and selection including shading and retarding culture. The natural flowering time of 'Yes Arang' is late October. This cultivar was yellow in color, single in flower type for the spray type cut-flower. The diameters of flower and flower center were 4.3 cm and 1.2 cm, respectively. Year round production was possible by shading or lighting treatment. Its number of flowers was 15.1 per plant. In natural and forcing cultivation, the days to flowering was 7 weeks after short day treatment. It has resistance to white rust and the vase life was about 17.2 days in autumn season.