• Korean journal of applied entomology
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• v.61 no.2
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• pp.349-356
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• 2022

Fall armyworm, Spodoptera frugiperda, is a invasive migratory pest of native to the tropical and sub-tropical regions that has recently invaded Korea with damage to cornfield. The study was conducted to investigate the development periods of S. frugiperda on artificial diet at six different temperatures. The developmental period from eggs to adult at 18, 21, 24, 27, 30 and 32℃ was 79.8, 54.2, 34.3, 28.4, 24.6 and 24.0 days, respectivery and decreased with increasing temperature. The pupal periods of females were shorter than males. Most of the larvae developed through six instar, but the ratio of 7 or more instar increased at low temperatures. The relationship between the development rate and temperature was fitted with by linear regression analysis. The lower development threshold for egg and larva development was 12.9℃ and 11.3℃, respectively, 12.6℃ for pupae and 11.8℃ for egg-to-adult development. The effective accumulative temperature for the development of the respective life cycle stages were 37.0 DD for eggs, 286.3 DD for larvae, 132.2 DD for pupae and 456.8 DD egg-to-adult development.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.211-219
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• 2023

Nutrient balance is an environmental indicator for assessing the potential of sustainable agriculture. Improving the use of arable land is crucial for reducing the nutrient balance. This study monitored soil water content, seepage water, crop growth, and nutrient balance in weighing lysimeters during forage barley (Hordeum vulgare L., "Yeongyang") cultivation from October to April. The study was conducted from 2020 to 2022, and the treatments included forage barley cultivation (clay loam, CL-FC; sandy loam, SL-FC) and bare soils. During the regeneration period (March to April), the soil moisture contents of bare and forage barley-cultivated soils were approximately 30-40% and 18.1-21.8%, respectively. The daily evapotranspiration of forage barley was 6.09 mm. The nitrogen balances for SL-FC and CL-FC were -0.43 to -2.93 g m^-2 and -0.79 to 0.75 g m^-2, respectively, which can be attributed to the higher nutrient uptake of forage barley in SL-FC than in CL-FC. Consequently, the forage barley cultivation in SL-FC can potentially reduce nutrient leaching during the spring rainy season. Furthermore, nutrient balance can be reduced by cultivating forage crops during the winter season.

• Research in Plant Disease
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• v.17 no.3
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• pp.351-357
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• 2011

Occurrence of Rice stripe virus (RSV) was investigated in Jeonnam province from 2008 to 2011. Incidence of RSV was surveyed in paddy fields during growth stage. In western and southern coast parts of 5 districts, Jindo, Wando, Shinan, Haenam and Muan, rice was severely damaged by RSV from 2008 to 2009. But, RSV didn't almost occur in 2010. Viruliferous ratio (VIR) of RSV from overwintered small brown plant hopper (SBPH, Laodelphax striatellus) showed 4.7%, 11.3%, 8.7%, and 2.8% from 2008 to 2011. It was highly recorded in Jindo, Wando, and Shinan of southwestern area. SBPH was collected by sucking machine at 1 $m^2$ with 3 replications per paddy field in March. The density of SBPH was high on March, but low on April in non-cultivated barley field from winter to spring. Farmer's plowing this season assumed to be a cause of SBPH density decrease. The number of SBPH was 7.7, 5.4, and 4.0 per $m^2$ during three years, respectively.

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.17-40
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• 2006

The trend towards forming economic blocs coupled with global economic arrangements such as DDA and FTA increase pressure on the liberalization of the agricultural sector. South Korea is taking part in the DDA negotiations. Once the DDA negotiations are implemented, the extent of liberation of the agricultural market is expected to be wider and timing of market opening is sooner than those effects of the UR agricultural agreement. A reduction in tariff rates and the government subsidy will follow, accordingly. However, many analysts in the agricultural sector express deep concern over a negative development in local agricultural market as demonstrated in China where the local market was dominated by imported agricultural products. This study aimed to investigate progress that China made in favor of the agricultural industry, including environment-friendly agricultural policy, and suggest ideas to drive the development of the agricultural industry in a better direction in Korea by comparing the two countries.

• Journal of Korean Society of Rural Planning
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• v.25 no.3
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• pp.11-18
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• 2019

It is widely known that agricultural plastic waste incineration by farmers may cause big forest fire or fine dust in rural areas. Hence, how to increase the rate of collection and recycling of the agricultural plastic waste is of concern to policy makers especially for rural environment. The purpose of this study is to find the determinants of the collection rate of agricultural plastic waste. This study used the data from 'Research on Agricultural Waste' by the Korea Environment Corporation from year 2012 to 2015 for 163 regions. This study found that the compensation rate for collection, the frequency of collecting services, and the quality of waste are important to increase the collection rate. And the regions with more elderly and low income people are more likely to have higher collection rate. Finally, the chief producing regions that are specialized in a certain crop shows higher collection rate.

• Mycobiology
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• v.34 no.4
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• pp.200-205
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• 2006

Phellinus genus belonged to Hymenochaetaceae of Basidiomycetes and has been well known as one of the most popular medicinal mushrooms due to high antitumor activity. This study was carried out to obtain the basic information for mycelial culture conditions of Phellinus linteus, P. baumii, and P. gilvus. According to colony diameter and mycelial density, the media for suitable mycelial growth of them were shown in MEA, glucose peptone, and MCM. The optimum temperature for mycelial growth was $30^{\circ}C$. Carbon and nitrogen sources were man nose and malt extract, respectively. The optimum C/N ratio was 10:1 to 5:1 with 2% glucose concentration, vitamin was thiamine-HCl, organic acid was succinic acid, and mineral salt was $MgSO_{4}{\cdot}7H_{2}O$.

• Mycobiology
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• v.35 no.1
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• pp.6-10
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• 2007

Present experiments were conducted to determine the possibility of artificial culture with various sawdust of P. gilvus. The pH value was 6.0 of oak sawdust, 6.5 of mulberry sawdust, 6.6 of elm sawdust, 6.3 of acacia sawdust and 6.1 of apple tree sawdust. Mycelial density on elm sawdust and acacia sawdust were lower than those of oak sawdust, and apple sawdust. Weight of fresh fruiting body showed that 179 g on oak tree, 227 g on oak sawdust, 21 g on elm tree, 76 g on elm sawdust, 106 g on apple tree, and 170 g on apple sawdust. Among them, the yield of oak substrates was the highest whereas acacia sawdust was the lowest, and it is concluded that the yields of sawdust substrates were higher than log substrates. P. gilvus grown on various sawdusts and logs used in this study have shown similar in anti-tumor activity against P388.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.25-39
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• 2021

The objective of this study is to analyze the value of attributes of agricultural products in school food service using hedonic price model and choice experiment. In the case of potatoes, bean sprouts, and tomatoes, environment-friendly agricultural products rather than conventional ones, and domestic price premiums exist rather than Chungnam. The higher the price, the higher the margin rate. Conventional agricultural products were more profitable than environment-friendly ones, and domestic products were more profitable than Chungnam. In consumer preferences, environment-friendly agricultural products are preferred over conventional agricultural products and local products (Chungnam, Cheonan, Asan) rather than domestic ones. This is the opposite result of the Hedonic price model estimation that Chungnam has a lower price premium than domestic in the case of origin. This study is meaningful by analyzing the attribute value of agricultural products used for school meals in Chungnam and comparing them with the willingness to pay consumers. With the results of this study, it is necessary that discussions on supplementing the value of local products used in Chungnam school food service.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.79-92
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• 2016

The objective of this study is to classify the types of rural areas (138 $si{\cdot}gun$) considering settlement environment by Decision Tree Method (CHAID). The CHAID method was used for decision tree algorithm and the seven dependant variables and 5 explanatory variables were selected, respectively. By decision tree method, rural areas were finally classified into six groups through three separate processes. City area, lower area in aging rate and higher area in farmland area ratio was analyzed to be relatively rich rather than other area in the case of settlement environment index. In the future, this study will be able to utilize as a reference to the planning of rural development projects.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.1
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• pp.139-143
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• 2010

The objective of our study was the formulation of a local strain of Mamestra brassicae nucleopolyhedrovirus-K1 (MabrNPV-K1) for the development of viral insecticide to control M. brassicae. To formulate MabrNPV-K1, feeding toxicities of various supplements and ultraviolet (UV)-protection were investigated. Optical brightener Tinopal UNPA-GX (Tinopal) as UV protectant and Bentonite had some toxicity themselves to increase the mortality. The protection of polyhedra from UV light radiation was observed only by Tinopal. The MabrNPV-K1 was formulated as a wettable powder form. The mortality of the formulation was higher and rapid than that of the un-formulated. This suggested the possibility of MabrNPV-K1 formulation as an effective biological control agent for M. brassicae.