잎브로콜리에 심각한 피해를 주는 배추좀나방의 적절한 방제시기 설정을 위한 기초자료로 이용하기 위하여 유충접종밀도와 잎브로콜리 피 해량의 관계를 분석하여 경제적피해허용수준과 요방제 수준을 설정한 결과는 다음과 같다. 배추좀나방 3~4령 유충을 주당 0, 0.5, 1.0, 1.5, 2.0 마리를 5월 24일에 접종하고, 6월 1일, 6월 9일, 6월 18일에 발생밀도와 엽수량을 조사한 결과, 초기 접종밀도가 증가할수록 배추좀나방의 발생 밀도는 증가하였고 시간이 경과할수록 엽수량은 감소하였다. 이를 토대로 배추좀나방의 접종밀도와 수량감소율을 회귀식을 이용하여 분석한 결 과 y=1636-394x (R 2 =0.79***)로 추정되었다. 잎브로콜리에서 5% 피해율을 경제적 피해한도로 볼 때 배추좀나방의 경제적피해허용수준은 10 주당 2~3마리이고, 요방제 수준은 10주당 1-2마리 수준으로 추정된다.

Economic injury levels (EILs) and economic control threshold (ET) were estimated for the Tea red spider mite, Tetranychus kanzawai Kishida(Acari, Tetranychidae) in Rubus coreanus Miquel. T. kanzawai density increased until the early-July and thereafter decreased in all plots except the non-innoculation plot where initial density of the mite were different each 0，5, 10, 20 and 40 adults per plant branch on May 7 in 2008. And the occurrence of the densities were increased higher innoculated density than different innoculation density. The yield was decreased with increasing initial mite density and thereby the rates of yield loss was increased with increasing initial mite density. And T. kanzawai occurrence density, yields and the rates of yield loss, where initial density of the mite were different each 0,2, 5, 10 and 20 adults per plant branch on May 8 in 2009 were similar tendency to 2008 year results. The relationship between initial T. kanzawai densities and the yield losses was well described by a linear regression, Y = 0.6545X + 3.0425 (R<SUP>2</SUP> = 0.93) in 2008, Y = 0.9031X + 2.0899(R<SUP>2</SUP> = 0.96) in 2009. Based on the relationship, the number of adults per plant branch(EILs) which can cause 5% loss of yield was estimated to be approximately 3.0 in 2008 and 3.2 in 2009. And the ET was estimated to be approximately 2.4 in 2008 and 2.6 in 2009. The relationship between initial T. kanzawai densities and occurrence density of mid-May considering the best spray timing against T. kanzawai was well described by a linear regression, Y = 0.471X + 2.495(R<SUP>2</SUP> = 0.95) in 2008, Y = 0.9938X + 3.1858(R<SUP>2</SUP> 二 0.96) in 2009. Based on the relationship, the number of adults per Ieaf(ET) in mid-May which can cause 5% loss of yield was estimated to be approximately 3.6 in 2008 and 5.8 in 2009.

Grey field slug, Deroceras reticulatum Muller, is one of the major pests of chinese cabbage, Brassica campestris. To determine the economic thresholds of grey field slug on chinese cabbage, the slugs were inoculated after planting 1 week into chinese cabbages with a density of 0, 2, 4, 8, 16 slugs per 16 chinese cabbages(1㎡) at the plastic house in the spring and autumn of 2008. The rates of damaged cabbages by slug inoculation were 10.7% at 2 slugs and 42.7% at 16 slugs in the spring, and 20.3% at 2 slugs and 59.2% at 16 slugs in the autumn. The linear relationships between the initial slugs density and yield reduction of chinese cabbage were as following ; Y = 286.07x + 548.62, R2=0.9524(in the spring cultivation), Y = 318.91x + 998.05, R2=0.9323(in the autumn cultivation). Based on these results, the economic threshold of grey field slug per 16 chinese cabbages(1㎡) was 2.52 slugs in the spring and 0.86 slugs in the autumn.

This study was conducted to develop the economic threshold for the diamondback moth (Plutella xylostella (L.) on Leaf Broccoli (leaf vegetable) in 2007. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 2.0, 4.0 larvae per plant) as initial density were established. We inoculated larvae in chesses cloth covering to survey larvae density change. When grown to eat, leaves of broccoli were harvested by periods. 60-70% of larvae were removed whenever we picked the leaves. High levels of larvae were associated with significant reductions in leaf yield. There were 85%, 64%, 58%, and 56% yield reductions from the diamond back moth larvae density in 0, 0.5, 1,0, 1.5, 2.0 per plant, respectively 25days after larvae inoculation. The regression equation used to predict leaf yield based on the number of initial larvae density per a plant was y=1635-393x(R2=0.79***). The economic injury level of diamondback moth on leaf broccoli was 2-3 larvae per 10 plants for a damage level of 5%. The economic thresholds was 1-2 larvae per 10 plants. Thus, the diamond back moth management should be initiated 1-2 larvae occurrence per plant.

Western flower thrips, Frankliniella occidentalis(Perg.), is one of the major pests of lettuce, Lactuca sativa. To develop the economic thresholds for western flower thrips on lettuce, the thrips was inoculated into two types of lettuce, green deeply lobed leaf lettuce which was harvested every week and red frilled & crinkled leaf lettuce which was harvested one time, with a density of 0, 1, 3, 7, 10 thrips per one lettuce after planting 1 week and 3 weeks at the plastic house in 2006, and 0, 1, 3, 5, 7 thrips per one lettuce after planting 1 week in 2007. There was close correlation between the initial thrips density and the marketable quantity of lettuce : y = -155.36x + 3564.7, r2=0.9724('06), y = -167.82x + 3474.5, r2=0.8897('07) in the green deeply lobed leaf lettuce inoculated the thrips after planting 1 week, y = -109.65x + 3549.1, r2=0.9384('06) in the green deeply lobed leaf lettuce inoculated the thrips after planting 3 weeks, y = -197.09x + 3334.9, r2=0.9707('06), y = -244.08x + 3425.9, r2=0.8914('07) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 1 week, y = -101.07x + 3457.6, r2=0.7334('06) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 3 weeks. The economic threshold for western flower thrips on lettuce was ranged 0.20～0.30 thrips per one lettuce in the blue type lettuce and 0.14～0.33 thrips per one lettuce in the red type lettuce.

This study examines the nonlinear relationship between financial development and economic growth in Pakistan using the threshold regression model for the period 1980-2017. We also employed quantile regression with 0.25, 0.50, and 0.75 quantiles of conditional distribution. The quantile regression is based on minimizing of sum of squared residuals. The result indicates that economic growth responds positively to financial development when the level of financial development surpasses the threshold value of 0.151. However, when financial development lies below the threshold value (that is, 0.151), its impact on economic growth is negative. Thus, when financial development of Pakistan surpasses the threshold level, it contributes more towards economic growth since greater level of financial development contributes more to boosts economic growth. This finding reveals that economic growth reacts differently to financial development, and the relationship between financial development and economic growth is U-shaped in Pakistan. Among the other variables, physical capital, labor force, and government expenditure exert a positive effect on economic growth. Furthermore, inflation rate and trade openness have an insignificant impact on economic growth. The results of quantile regression also confirm the non-linear relationship between financial development and economic growth in Pakistan. The finding of this study suggests revamping of financial sector policies in Pakistan.

The study investigates the relationship between the inflation rate and economic growth to find out the optimal inflation threshold for economic growth. Therefore, this study applied an ordinary least square model (OLS) and the ordinal regression model, and collected the time-series data from 1996 to 2017 to test the relationship between inflation and economic growth in the short-term and long-term. The sample fits the model and is statistically significant. The study showed that 96.6% of correlation between inflation rate and economic growth are close and 4.5% of optimal inflation threshold is appropriate for economic growth. It finds that the optimal inflation threshold is base to perform economic growth, besides the inflation rate is positively related to economic growth. The results support the monetary policy appropriately. This study identifies issues for Government to consider: have a comprehensive solution among macroeconomic policies, monetary policy, fiscal policy and other policies to control and maintain the inflation and stimulate growth; have appropriate policies to regulate inflation to stimulate economic growth over the long term; set a priority goal for sustainable economic growth; not pursue economic growth by maintaining the inflation rate in the long term, but take appropriate measures to stabilize the inflation at the optimal inflation threshold.