• Research in Plant Disease
• /
• v.20 no.4
• /
• pp.235-244
• /
• 2014

Clubroot and Fusarium wilt of cole crops (Brassica oleracea L.) are destructive diseases which for many years has brought a decline in quality and large losses in yields all over the world. The breeding of resistant cultivars is an effective approach to reduce the use of chemical fungicides and minimize crop losses. This study was conducted to evaluate the resistance of 60 cabbage (B. oleracea var. capitata) and 6 broccoli (B. oleracea var. italica) lines provided by The RDA-Genebank Information Center to clubroot and Fusarium wilt. To investigate resistance to clubroot, seedlings of the genetic resources were inoculated with Plasmodiophora brassicae by drenching the roots with a mixed spore suspension (1 : 1) of two isolates. Of the tested genetic resources, four cabbage lines were moderately resistant and 'K166220' represented the highest resistance to P. brassicae. The others were susceptible to clubroot. On the other hand, to select resistant plants to Fusarium wilt, the genetic resources were inoculated with Fusarium oxysporum f. sp. conglutinans by dipping the roots in spore suspension of the fungus. Among them, 17 cabbage and 5 broccoli lines were resistant, 16 cabbage lines were moderately resistant, and the others were susceptible to Fusarium wilt. Especially, three cabbage ('IT227115', 'K161791', 'K173350') and two broccoli ('IT227100', 'IT227099') lines were highly resistant to the fungus. We suggest that the resistant genetic resources can be used as a basic material for resistant B. oleracea breeding system against clubroot and Fusarium wilt.

• Korean journal of applied entomology
• /
• v.53 no.2
• /
• pp.193-197
• /
• 2014

Transgenic crops that produce insecticidal toxins have a great potential for controlling target pest insects, but there is a growing concern about unintended influences on non-target species. In the present study, the preferences and performance of non-target green peach aphid, Myzus persicae (Sulzer), on transgenic cabbages (Brassica oleracea) that produce Bt toxin (Cry1Ac1) and untransformed control plants were investigated as a part of risk assessment. In a free-choice situation, the number of nymphs larviposited by 10 winged adults over 3 days was $21.9{\pm}1.8$ and $22.5{\pm}2.2$ on transgenic and the control plants, respectively, indicating that the aphids did not discriminate between the two types of plants. In a performance assay, the development time (D) and intrinsic rate of increase (rm) of wingless aphids reared on transgenic and control plants were also similar (D, $5.8{\pm}0.2$ and $5.9{\pm}0.1$ (days) and rm, $0.7{\pm}0.1$ and $0.8{\pm}0.1$, for transgenic and control plants, respectively). These results suggest that M. persicae is not significantly affected by transgenic Bt cabbage.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.1
• /
• pp.9-19
• /
• 1992

To ditermine the accumulation of Cu and Pb in crops grown on Sludge-treated Soils, four crop plants, green onion(A Ilium ascalonicum L.), radish(Raphanus sativus L.), potato(Solanum tuberosum L.) and Chinese cabbage(Brassica pekinensis Rupr), were grown in greenhouses on soils treated with municipal sewage sludge at different levels of 0, 22.5, 45, and 90ton/ha as soil dry weight. The contant of heavy metals were analyzed in plant parts of the crop species and the statistical characteristics were investigated. The results were as follows: 1. Cu and Pb contents in experimental plants were increased in accordance with quanti of sludge applied. 2. Accumulation of Cu and Pb in leaves of plants was increased in order of radish

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.4
• /
• pp.231-238
• /
• 2009

This study was carried out to investigate the effect of vegetative buffer to reduce runoff and soil and nutrient loss at highland agricultural area. The soil of experimental field was classified as Ungyo series (Fine, Humic Hapludults). An area of each field with lysimeter was $50m^2(width\;2.5m{\times}length\;20m)$ and was a gradient of 17%. Chinese cabbage (Brassica campestris L.) was cultivated by general management in each field. For establishing vegetative buffer, rye (Secalecereale L.), tall fescue (Festucaarundinacea Schreb) and orchard grass (Dactylis glomerata L.) were planted at the edge of field. Rye buffers were 1m, 2m and 4m wide. Both orchard grass and tall fescue buffers were 2m wide. Vegetative buffers were set up in September 2005 and chinese cabbage was planted in June 2006. Soil loss, runoff and nutrient loss were measured from June to August in 2006. Since the precipitation amount was heavy in July, amounts of runoff, soil erosion and nutrient loss were the highest in July during this study period. In comparison with control, vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m reduced runoff by 3%, 1% and 2%, respectively. In comparison among width of rye buffer, rye 1m, rye 2m, and rye 4m reduced by 1%, 4% and 13%, respectively. Vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m showed the reducing of soil loss by 59%, 46% and 28%, respectively. In comparison among width of rye buffer, the highest reducing effect of 88% was observed in 4m treatment. Additionally, vegetative buffer reduced N, P and K losses in runoff and eroded soil which were 10 to 54%, 7 to 24% and 11 to 21%, respectively. In different widths, wider vegetative buffer showed lower loss of N, P and K in runoff and eroded soil. As a result of this study, the vegetative buffer of rye was most effective for reducing runoff and soil loss in comparisons with other plants. In addition, wider range of buffers recommended for reducing runoff and soil loss, if possible.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.3
• /
• pp.212-216
• /
• 2012

BACKGROUND: Green manure and graminaceousmanure crops have several benefits, such as improving soil physical and chemical properties and utilizing excessive greenhouse nutrients that they have a potential to be a water pollutant source. METHODS AND RESULTS: The objective of this study was to investigate nitrogen (N) supplying capabilities of green manure and graminaceous manure crops for lettuce (Lactuca sativa L.) and Chinese cabbage (Brassica campestris L.) grown under greenhouse conditions. For this two leguminous manures (Crotalaria juncea (Cr.) and Sesbaniaexaltata (Se.)) and two graminaceous manures (Sorghum bicolor; Haussolgo(Ha.) and Sudangrass (Sg.)) in the greenhouse were grown, cut, and incorporated into the greenhouse soil before planting. Chemical nitrogen (N) fertilizer rate was estimated based on N recommendation for lettuce and Chinese cabbage. 100% of the N recommended rates (1N) were 70 kg N $ha^{-1}$ for lettuce and 60 kg N $ha^{-1}$ for Chinese cabbage and 50% of the N recommendation rates (0.5N) were 35 kg N $ha^{-1}$ for lettuce and 30 kg N $ha^{-1}$ for Chinese cabbage. Nitrogen treatments were control (0N), Cr., Se., Cr + 0.5 N, Se + 0.5 N, Ha + 0.5 N, Sg + 0.5 N, and N recommendation rate (1N). Incorporated N from green manure and graminaceous manure crops were 130, 116, 93, and 87 kg N $ha^{-1}$ for Cr., Se., Ha., and Sg., respectively. Lettuce and Chinese cabbage were grown after incorporated green manure crops into the greenhouse soil. There was no significant difference in lettuce and Chinese cabbage yields under N treatments except control (0 kg/ha). Nitrogen use efficiency (NUE)was from 44% to 73% and the highest NUE was under Se. treatment. Although yields were not statistically different under N treatments except control, actual yield increase ranged from 170 to 1,100 kg/ha for lettuce and ranged from 2,770 to 5,210 kg/ha for Chinese cabbage compared to yield under N recommendation rate. Estimated economic benefit from this would be higher approximately between \2,770,000 and \5,210,000/ha under N treatments except control than the N recommendation rate. CONCLUSION: These results suggest that incorporating green manure crops, such as Cr. and SeSe. into soil or adding 0.5 N after incorporation of them can be beneficial in many ways in that it increases economic return because of yield increase, reduces the use of chemical N, and decreases the negative environmental impact on water quality because excessive N in the greenhouse soil can be used by green manure crops during the fallow.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.25 no.4
• /
• pp.398-403
• /
• 2023

Process-based K-cabbage model is based on physiological processes such as photosynthesis and phenology, making it possible to predict crop growth under different climate conditions that have never been experienced before. Current first-stage process-based models can be used to assess climate impact through yield prediction based on climate change scenarios, but no comparison has been performed between big data obtained from the main production area and model prediction so far. The aim of this study was to find out the direction of model improvement when using the current model for yield prediction. For this purpose, model performance evaluation was conducted based on data collected from farmers growing 'Chungwang' cabbage in Taebaek and Samcheok, the main producing areas of Chinese cabbage in highland region. The farms surveyed in this study had different cultivation methods in terms of planting date and soil water and nutrient management. The results showed that the potential biomass estimated using the K-cabbage model exceeded the observed values in all cases. Although predictions and observations at the time of harvest did not show a complete positive correlation due to limitations caused by the use of fresh weight in the model evaluation process (R²=0.74, RMSE=866.4), when fitting the model based on the values 2 weeks before harvest, the growth suitability index was different for each farm. These results are suggested to be due to differences in soil properties and management practices between farms. Therefore, to predict attainable yields taking into account differences in soil and management practices between farms, it is necessary to integrate dynamic soil nutrient and moisture modules into crop models, rather than using arbitrary growth suitability indices in current K-cabbage model.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.17 no.4
• /
• pp.333-339
• /
• 2015

A thermal time-based phenology model of Kimchi cabbage was developed by using the field observed growth and temperature data for the purpose of accurately predicting heading and harvest dates among diverse cropping systems. In this model the lifecycle of Kimchi cabbage was separated into the growth stage and the heading stage, while the growth amount of each stage was calculated by optimal mathematical functions describing the response curves for different temperature regimes. The parameter for individual functions were derived from the 2012-2014 crop status report collected from seven farms with different cropping systems located in major Kimchi cabbage production area of South Korea (i.e., alpine Gangwon Province for the summer cultivation and coastal plains in Jeonnam Province for the autumn cultivation). For the model validation, we used an independent data set consisting of local temperature data restored by a geospatial correction scheme and observed harvest dates from 17 farms. The results showed that the root mean square error averaged across the location and time period (2012-2014) was 5.3 days for the harvest date. This model is expected to enhance the utilization of the Korea Meteorological Administration's daily temperature data in issuing agrometeorological forecasts for developmental stages of Kimchi cabbage grown widely in South Korea.

• Journal of Bio-Environment Control
• /
• v.26 no.4
• /
• pp.297-300
• /
• 2017

Plant factory can control artificially the environments for crop cultivation, so they can produce high quality agricultural products all year round. This study was carried to select suitable kohlrabi cultivar for hydroponics in a closed-type plant factory system. We used three cultivars of red kohlrabi, 'Asac kohl', 'Kolibri', and 'Purple king' as plant materials. The artificial light source was LED light, light intensity and photoperiod were $249{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and 12/12 hours (day/night period), respectively. Hydroponic cultivation type was used circulating deep flow technique. At 43 days after transplanting, fresh weight of whole plant and tuber and leaf area were not significantly different among cultivars. Shoot dry weight and tuber dry weight were highest in 'Asac kohl' cultivar, and number of leaves was highest in 'Purple king' cultivar. Sugar content and yield were highest in 'Asac kohl' cultivar. Considering the growth and marketable yields, 'Asac kohl' was the optimal kohlrabi cultivar for hydroponic cultivation in a closed-type plant factory system.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.12
• /
• pp.1674-1680
• /
• 2000

A study was conducted to compare the feeding value of urea treated and untreated mustard straw (MS) for sheep. Treated MS was prepared by adding urea-N at 1.84% and followed by packing in a pit silo for 21 days. Two groups of six empty Avikaline ewes were fed untreated (UTMS) and treated (TMS) mustard straw along with 200 g concentrate per head daily for 90 days. Untreated MS had 0.41% N and the urea treatment increased its N value to 1.58 %. The cell wall constituents were decreased in the TMS except for cellulose which remained unaffected. Dry matter intake of TMS was consistently higher than that of UTMS. Digestibility of DM, OM and fibre fractions of MS improved by the urea treatment. Ewes in both groups were in positive N balance while % N retention was lower in UTMS (26.30%) than in TMS (52.14%). The TMS fed group on average consumed 30.2 g DM, 2.9 g digestible crude protein and $0.2MJ\;DE\;per\;kg\;BW\;day^{-1}$ and maintained their weight whereas, the UTMS fed ewes lost weight. The VFA concentration in rumen liquor was higher in TMS than in UTMS. Total-N, ammonia-N and TCA-precipitable-N were also higher in TMS fed ewes. Blood glucose concentrations in the two groups were similar at initiation of the study. However the glucose concentration of UTMS fed group was significantly (p<0.01) lower than those fed UTMS at the termination of the study. Urea-N concentration was also higher in TMS fed group after 90 days of feeding period. It is concluded that urea treatment of MS improved N value of MS from 0.41% to 1.58% along with sizable improvement in nutritive value and in conjunction with 200 g concentrate, TMS can serve as maintenance ration for sheep. ($ME_{lakt}/ME_{m}=1.46$).

• Korean Journal of Environmental Agriculture
• /
• v.39 no.1
• /
• pp.50-57
• /
• 2020

BACKGROUND: Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings. METHODS AND RESULTS: The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P₂O₅, K₂O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K₂O concentration of red pepper seedlings increased, but the concentrations of P₂O₅, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH. CONCLUSION: In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.