For the setting of control timing, the number of overwintering eggs on host plants and population density of Metcalfa pruinosa nymphs and adults was surveyed in the three peach orchards. According to a survey of the overwintering eggs density (∅2~3㎝, 20㎝ branches) of M. pruinosa on host plants, 221.8 in Mugunghwa trees, 189.3 Oak trees, and 152.7 Acacia trees, and 57.0 Peach showed the number of eggs laid. Examined peach branches within the 50cm (∅1~5cm) was not found population densities of M. pruinosa nymphs and adults, and it was also very low in the sticky trap. The peak density of the adult was highest at 5.4 per trap on August 7 after being first investigated on July 16 in a string wrap survey, and then decreased.
In the peach orchard, it is judged that the control of the M. pruinosa is due to be 20 days after the end of the insect hatching, and that distribution of host plants is more important in the outside region than inside region.
This study was performed to establish the control strategies effectively using Eco-friendly agricultural materials (EFAM) and natural enemy when cultivating autumn-type leaf perilla and to investigate the population densities of seasonal major pests such as Tetranychus urticae (two-spotted spider mite, TSSM), Broad mite (Polyphagotarsonemus latus), Aphis egomae, and Pyrausta panopealis. TSSM showed the occurrence in the seedling stage from August to the end of September and controlled using EFAM in the nursery. Broad mites had a low occurrence in October, December, and the following year showed the density of two or more leaves per leaf from February. Aphis egomae was locally prevented around the area of occurrence, and it showed more than five per leaf in October. Pyrausta panopealis seemed to occur from August to September. Aphis egomae is control using high-toxic EFAM before the overwintering and prevents it from using banker plants planted barley in the winter. Pyrausta panopealis is protected by biological pesticides in August registered in the leaf perilla.
Eighty kinds of pesticides registered in the peach and leaf perilla were assessed the efficacy against the 4th nymph stage of citrus flatid planthopper. Plant of Sharon, host plant preferred by citrus flatid planthopper, was cut from 5 to 7 cm and dipped 10 seconds into recommended concentrations of pesticides, respectively, and then dried naturally for the 30 minutes. New shoot of Plant of sharon treated pesticides and 10 to 15 final nymphs of citrus flatid planthopper put together in the 50㎖ tube and the number of live nymphs was investigated after 48 hours. Pesticides showing mortality over 90% were seven, namely, bifenthrin EW, Rhamda-cyhalothrin EC, Clothianidin SC, Benfuracarb SG, Chloropyrifos WP, Bifenthrin+methoxypenozide SC, Chloropyrifos+imidacloprid WP. When the forest surrounding the peach and leaf perilla was occurred and damaged by citrus flatid planthopper, the use of these pesticides is judged to be effective in the control of this pest.
This study was carried out to introduce of agronomic characteristics, forage yields and quality of Sorghum × Sudangrass hybrids ‘Cadan 99B’ and ‘Sweet Sioux WMR’ from 2015 to 2016 in middle and southern regions of Korea. The field experiment design was complete in seven varieties with three repetitions. Sorghum × Sudangrass hybrids were sown on mid-May in middle region, and end-May in southern region of Korea, in 2015 and 2016. The observed average heading date of Cadan 99B and Sweet Sioux WMR were July 22. The heading dates of Cadan 99B and Sweet Sioux WMR were 8 days earlier than SX-17 and 5 days earlier than brown mid-rid (BMR) Revolution. The sugar contents of Cadan 99B and Sweet Sioux WMR were 6.5 and 6.9 Brix°, respectively. Comparison with BMR variety, the sugar contents of Candan 99B and Sweet Sioux WMR were 0.2 and 0.6 Brix° higher than Revolution, respectively. The average of dry matter (DM) yield for 2 years and 2 regions of Cadan 99B (24,587kg/ha) were the highest among the seven varieties, but there was no significant difference among other varieties except headless control variety Jumbo (19,119kg/ha) and LATTE (20,778kg/ha) (p>0.05). The crude protein (CP) and in vitro dry matter digestibility (IVDMD) of Cadan 99B were 7.5% and 60.2%, and Sweet Sioux WMR were 6.9% and 60.7%, respectively. The results of this study indicated that Sorghum × Sudangrass hybrids Cadan 99B and Sweet Sioux WMR are earlier heading dates and higher than SX-17, and high yields of DM in middle and southern regions of Korea.
It is necessary to understand of temporal and spatial dynamics by establishing a periodical monitoring system for theproper management in small brown planthopper (SBPH). A dataset is including the number of SBPHs by location, collectionmethod [aerial collection net (AeCN) or light trap (LT)] and period (May~Aug.) for five years (2011~2015), and missingvalues were imputed using multiple imputation methods. Of the 15,848 individuals collected, approximately 47% and 52.9%were collected using the AeCN and LT methods, respectively. A high incidence of migratory SBPHs was observed duringJulian days 144-166 using the AeCN method. Generally, the migratory SBPHs from China composed 39.4% of the totalpopulations of SBPHs. These results would provide valuable information to predict the incidence period of migratory SBPHsand establish a proactive management system against SBPH.
신재생, 친환경 에너지에 대한 관심의 증가로 최근 상당수의 풍력 발전기가 설치되고 있다. 특히, 육상과 달리 부지 확보의 어려움도 없고 고품질의 바람을 얻을 수 있다는 점에서 해상 풍력 발전기가 더욱 주목을 받고 있다. 이와 같은 장점을 가진 해상 풍력 발전기는 육상의 조선소 등에서 제작된 후, 해상 크레인을 이용하여 운용 지점까지 이송되어 설치되는데, 이때 그 크기의 거대함과 고가라는 이유로 무엇보다 안전이 보증되어야 한다. 따라서 본 연구에서는 해상 풍력 발전기의 이송 및 설치 시 안전성을 보증하기 위한 근거로서, 다물체계 동역학 기법을 활용하여 해상 크레인에 연결된 해상 풍력 발전기의 동역학 해석을 수행하였다. 그 결과, 본 기법이 해상 풍력 발전기의 이송 및 설치방법에 대한 검증용으로 충분히 활용 가능함을 확인할 수 있었다.
Economic injury level was estimated for the sweetpotato whitefly, Bemisia tabaci on greenhouse tomato (Lycopersicon esculantum cultivar pinktop). In the greenhouse, seedling tomato transplanted at mid-April and inoculated B. tabaci at late-April with the densities of 0, 1, 3, 9, 27, 54, 108 and 216 per plant. Only 108 and 216 inoculation densities increased until mid-July. Total weight of fruits was not showed the differences by initial whitefly density; however, the total weight of marketable fruits decreased significantly among plots by higher initial whitefly density. The rates of yield loss increased with increasing whitefly density, resulting in 8.3, 14.0, 29.7, 29.7, 25.7, 40.4, and 69.4% reduction in each of the plots, respectively. The relationship between initial whitefly densities and yield losses was well described by a linear regression, Y= 18.09X+6026.5, R2=0.8504. Based on the relationship, the number of adults per plant which can cause 5% loss of yield was estimated to be approximately 17.