This study was conducted with the aim of confirming the impact and relative contribution of extreme weather to dry matter yield (DMY) of silage corn in the central inland region of Korea. The corn data (n=1,812) were obtained from various reports on the new variety of adaptability experiments conducted by the Rural Development Administration from 1978 to 2017. As for the weather variables, mean aerial temperature, accumulated precipitation, maximum wind speed, and sunshine duration, were collected from the Korean Meteorological Administration. The extreme weather was detected by the box plot, the DMY comparison was carried out by the t-test with a 5% significance level, and the relative contribution was estimated by R2 change in multiple regression modeling. The DMY of silage corn was reduced predominantly during the monsoon in summer and autumn, with DMY damage measuring 1,500-2,500 kg/ha and 1,800 kg/ha, respectively. Moreover, the relative contribution of the damage during the monsoons in summer and autumn was 40% and 60%, respectively. Therefore, the impact of autumn monsoon season should be taken into consideration when harvesting silage corn after late August. This study evaluated the effect of extreme weather on the yield damage of silage corn in Korea and estimated the relative contribution of this damage for the first time.

The purpose of this study is to extract climate element affecting coffee yield by growth period using data of production and cultivation area of coffee and climate data for 2000-2018. During the analysis period, the production of coffee in Vietnam has been consistently increasing, but Ðăk Lăk in the Central Highlands, the main cultivation area for coffee production, has recently stagnated in the trend of increasing yield. The yield of Lâm Đồng, located in the relatively highlands of the Central Highlands, is steadily increasing. Coffee yields of Ðăk Lăk is negatively correlated with the temperature during flowering period, and is also significantly negatively correlated with the maximum temperature and precipitation during the late growing period. On the other hand, Lâm Đồng, located at a relatively high altitude, has a positive correlation with temperature during the late growing period. It is analyzed that the lower the altitude, the higher the temperature, the lower the coffee productivity due to the high temperature appearance, and the lower the low temperature appearance in the high altitude region.

The purpose of this study is to examine the effect of climatic elements on the arabica coffee yield during the various growth stages of coffee plant for the period of 1996-2017 over Costa Rica. For the future scenario, change rate of arabica coffee yield is also estimated using the data of production and cultivated area. The cultivation area and the yield of arabica coffee has been decreasing since the 1990s in Costa Rica. The decreasing trend in arabica coffee yield could have a negative effect on Costa Rica’s coffee industry in the future. During the dry season, the yield of arabica coffee has significant negative correlation with precipitation at the stage of flowering in the month of February. In case of wet season, coffee yield and temperature were negatively correlated while precipitation showed positive association with coffee yield at the stage of growing period in the month of August. However, the observation revealed the excessive precipitation drastically reduced arabica coffee yield in 2013 during August, the month of wet season. According to the RCP 4.5 and RCP 8.5 climate change scenarios, due to high temperature and fluctuated precipitation the yield of arabica coffee is unstable and the future of coffee industries is also insecure.

The purpose of this study is to extract climate factors affecting sweet persimmon yield by growth period and estimate the rate of future sweet persimmon yield using data of production and cultivation area of sweet persimmon and climate data for 1998-2015. During the analysis period, the cultivation area of sweet persimmon in Gyeongnam has been consistently decreasing, but sweet persimmon yield has increased. Climate factors that have statistically significant effects on sweet persimmon yield are mean temperature, maximum temperature, precipitation, precipitation days, and sunshine hours. The sweet persimmon yield is a statistically positively correlated with temperature and sunshine hours and negatively correlated with precipitation during the flowering period (April to May). The sweet persimmon yield is statistically positively correlated with precipitation in the growing period (June to August) and negatively correlated with temperature in maturity period (September to November). Future sweet persimmon yield is estimated to have a steadily decreasing rate of change in future climate change scenarios, RCP4.5 and RCP8.5.

objective of the current study was to evaluate the change of rice yield under the projected climate change condition. The rice model included in "Decision Support System for Precise Management of Rice Culture” developed in Crop Environment and Production Technology Lab. of Seoul National University was validated prior to simulation experiment. For model input, the daily weather data were generated by SIMMETEO method from the monthly normal maximum and minimum temperatures and precipitation of the current period, 1971-2000 and the three periods in the future, 2011-2040, 2041-2070, and 2071-2100. The climate change projected using A1B emission scenario by Korea National Meteorological Institute was used for the periods in the future. Simulation experiments were carried out using three cultivars, Odaebyeo, Hwasungbyeo and Dongjinbyeo under six transplanting dates from May 10 to June 30. The vegetative and ripening period is expected to decrease respectively by 10 and 30 days in 2071-2100. High temperature-induced sterility is projected to increase by about 8% until 2071-2100. Rice yield on national average was simulated to decrease by 3, 7, and 13 % in 2011-2040. 2041-2070, and 2071-2100 periods, respectively. Though adaptation strategies that select the cultivar among the current cones and change the transplanting date would alleviate the yield decrease, the yield decrease of about 7% is still anticipated in 2071-2100.

Field experiments were conducted to determine the physiological and biochemical basis of the interactive effect of sulphur (S) and nitrogen (N) application on seed and xanthotoxin yield of Ammi majus L. Six treatments were tested (T1 = control-without manure and fertilizers, T2 = manure @ 9 kg plot-1-10~;t~;ha-1,~;T3=A0N50K25P25,~;T4=S40N50K25P25,~;T5=S40N100K25P25~;T6=S20+20N50+50K25P25) ). Nitrate reductase (NR) activity and ATP-sulphurylase activity in the leaves were measured at various phonological stages, as the two enzymes catalyze rate-limiting steps of the assimilatory pathways of nitrate and sulphate, respectively. The activities of these two enzymes were strongly correlated with seed and xanthotoxin yield. The highest nitrate reductase activity, ATP-sulphurylase activity and xanthotoxin yield were achieved with the treatment T4 . Any variation from this treatment decreased the activity of these enzymes, resulting in a reduction of the seed and xanthotoxin yield in Ammi majus L. The higher seed and xanthotoxin yield achieved in Ammi majus L. at treatment T4 could be due to optimization of leaf soluble protein and photosynthetic rate, as these parameters are Influenced by S and N assimilation.

The atmospheric carbon dioxide concentration is ever-increasing and expected to reach about 600 ppmv some time during next century. Such an increase of CO2 may cause a warming of the earth's surface of 1.5 to 4.5~circC , resulting in great changes in natural and agricultural ecosystems. The climatic scenario under doubled CO2 projected by general circulation model of Goddard Institute for Space Studies(GISS) was adopted to evaluate the potential impact of climate change on agroclimatic resources, net primary productivity and rice productivity in Korea. The annual mean temperature was expected to rise by 3.5 to 4.0~circC and the annual precipitation to vary by -5 to 20% as compared to current normal climate (1951 to 1980), resulting in the increase of possible duration of crop growth(days above 15~circC in daily mean temperature) by 30 to 50 days and of effective accumulated temperature(EAT=∑Ti, Ti~geq 10~circC ) by 1200 to 1500~circC . day which roughly corresponds to the shift of its isopleth northward by 300 to 400 km and by 600 to 700 m in altitude. The hydrological condition evaluated by radiative dryness index (RDI =Rn/ ~ell P) is presumed to change slightly. The net primary productivity under the 2~times CO2 climate was estimated to decrease by 3 to 4% when calculated without considering the photosynthesis stimulation due to CO2 enrichment. Empirical crop-weather model was constructed for national rice yield prediction. The rice yields predicted by this model under 2 ~times CO2 climatic scenario at the technological level of 1987 were lower by 34-43% than those under current normal climate. The parameters of MACROS, a dynamic simulation model from IRRI, were modified to simulate the growth and development of Korean rice cultivars under current and doubled CO2 climatic condition. When simulated starting seedling emergence of May 10, the rice yield of Hwaseongbyeo(medium maturity) under 2 ~times CO2 climate in Suwon showed 37% reduction compared to that under current normal climate. The yield reduction was ascribable mainly to the shortening of vegetative and ripening period due to accelerated development by higher temperature. Any simulated yields when shifted emergence date from April 10 to July 10 with Hwaseongbyeo (medium maturity) and Palgeum (late maturity) under 2 ~times CO2 climate did not exceed the yield of Hwaseongbyeo simulated at seedling emergence on May 10 under current climate. The imaginary variety, having the same characteristics as those of Hwaseongbyeo except growth duration of 100 days from seedling emergence to heading, showed 4% increase in yield when simulated at seedling emergence on May 25 producing the highest yield. The simulation revealed that grain yields of rice increase to a greater