• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.213-224
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• 2019

There is an increasing frequency in the occurrence of abnormal weather phenomena such as sharp increases and decreases in temperature. Under these weather conditions, the heading time of rice changes unexpectedly, which poses problems in agriculture. Therefore, we investigated the effect of temperature on the heading response at different growth stages in rice. During the period from transplanting to heading, the plants were subjected to different temperature treatments, each for a 9-day period, to observe the heading response. For the heading date analysis, "heading date" was defined as the number of days from transplanting to the appearance of the first spikelet. We found that the influence of temperature increased in the order of rooting stage, followed by meiosis, early tillering, spikelet differentiation, and panicle initiation stage in all ecological types and cultivars. In particular, unlike the results reported previously, the effect of temperature on heading during the photo-sensitive period was very small. Meanwhile, the influence of temperature on vegetative growth response at different growth stages was not consistent with heading response. These results can be used as basic data for predicting the variation in heading date owing to temperature variation at each growth stage. In addition, we propose that the concept of day length should be included in determining the influence of temperature on the photo-sensitive period.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.149-149
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• 2022

As the average temperature rises due to climate change, damage to caused by rising temperatures is spreading all over the world. If soybeans are exposed to high temperature during the reproductive stage, pod setting rate and seed weight is reduced, therefore, various studies are needed to prevent crop damage due to high temperature. This study is to research the effect of high temperature on yield decrease during the grow stage of soybean.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.260-260
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• 2017

High temperature is one of major environmental stress. Heat in flowering season of wheat is able to effect negatively to fertilization and also heat effect to maturity. Therefore, Heat stress effects severely to qualities of wheat and yield productivity. In this study, we evaluated to agronomic characteristics and qualities by high temperature in 13 Korean wheat varieties. Weight of 1,000 grains decreased when wheat got the heat stress. In particular, heat stress during the heading dates were more damaged than after the end of heading dates except two varieties Keumkang and Jokyoung. Plant height of each cultivar under high temperature and normal field averaged 80.5 cm and 83.0cm, respectively. The length of spike and awn in each cultivar were similar to both condition. Flour yield and gluten contents of most heat damaged wheat decreased. Under the temperature, protein contents of six varieties like as Keumkang, Baekjoong, Hojoong, Yeonbaek, Joah and Shinmichal 1 decreased but the others increased. The sedimentation values (SDSF) of four varieties decreased under the high temperature. But SDSF of 7 varieties like as Baekjung, Suan, Hojoong, Jojoong, Uri, Shinmichal and Shinmichal 1 was increased. The lightness (L) of wheat flour derived from high temperature treated wheat was darker than non-treated wheat. As a result of this research, we confirmed that agricultural traits and qualities decreased in heat damaged wheat.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.107-107
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• 2022

The increase in atmospheric temperature due to climate change prolongs the period of exposure to high-temperature environments during rice cultivation. In particular, high-temperature during early seed development greatly affects on the productivity and quality of rice. The high temperature at this time not only affects the transport and distribution of assimilates from leaves to seeds and the accumulation of starch in the seeds, but also affects the leaves, which are the production organs of assimilates, and increases the consumption of assimilation products due to an increase in respiration. Therefore, in this study, rice was grown in temperature gradient chambers(TGC) to analyze the effects of high temperature on physiological responses, assimilate production, and changes in gene expression in rice leaves. Analysis of chlorophyll and sugar contents and RNA-seq experiments were performed using flag leaves collected under normal and elevated temperature conditions, respectively, during the early seed development stage, and then these results were comprehensively discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.163-170
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• 2016

Heading time is important element for yield and quality in crops. Among day length and temperature which influence on heading, temperature effect has not been investigated well. To investigate temperature effect on heading, heading date and plant growth characters were checked under the low and high temperature conditions in short day length. Analyzing heading date of six Korean varieties under the high and low temperature condition, heading date of varieties were delayed under low temperature. In the low temperature condition, dry weight and area of leaf were reduced. Varieties showing more delay of heading under low temperature also showed more reduction in leaf area. After selecting three varieties showing significant difference in leaf growth and heading date under different temperature conditions, nutrient contents of plant were analyzed. Nitrogen content was reduced in leaf and shoot under the low temperature condition. OsNRT2.3, nitrate transporter, was significantly down regulated in varieties showing more heading delay. Available phosphate content was decreased in leaf, but increased in shoot due to reduction of phosphate mobility. OsPT1, phosphate transporter regulating phosphate uptake, was more down regulated in varieties showing more heading delay. OsPT6, phosphate transporter regulating phosphate transport in plant, was also significantly down regulated in those varieties. With these data, we expected that active nitrogen and available phosphate uptake and transport in plant would increase leaf growth then might reduce heading delay under the low temperature condition.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.168-168
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• 2022

According to the 5th Climate Change Report, global average temperature in 2081~2100 will increase 1.8℃ based on RCP 4.5 and 3.7℃ based on RCP 8.5 from the current climate value (IPCC Working Group I AR5). As temperature is expected to increase due to global warming and the intensity and frequency of rainfall are expected to increase, damage to crops is expected, and countermeasures must be taken. This study intends to evaluate rice growth in terms of nitrogen utilization efficiency according to future climate change conditions. In this experiment, Oryza sativa cv. Shindongjin were planted at the SPAR facility of the NICS in Wanju-gun, Jeollabuk-do on June 10, and were planted and grown according to the standard cultivation method. Cultivation conditions are high temperature, high CO₂ (current temperature+4.7℃·CO₂ 800ppm), high temperature (current temperature+4.7℃·CO₂ 400ppm), current climate (current tempreture·CO₂ 400 ppm). Nitrogen was varied as 0, 9, 18 kg/10a. The N content and C/N ratio of all rice leaves, stems, and seeds increased at high temperature, and the N content and C/N ratio decreased under high temperature and high CO₂ conditions com pared to high temperature. Compared to the current climate, NUE increases by about 8% under high temperature and high CO₂ conditions and by about 2% under high temperature conditions. This seems to be because the increase in temperature and CO₂ induced the increase in biomass. ANUE related to yield decreased by about 70% compared to the current climate under high temperature conditions, and decreased by about 45% at high temperature and high CO₂, showing a tendency to decrease compared to high temperature. This appears to be due to reduced fertility and poor ripening due to high temperature stress. However, as the nitrogen increased, the number of ears and the number of grains increased, slightly offsetting the production reduction factor.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.103-112
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• 2001

The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.159-165
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• 2018

The seed yield of summer plants is affected by climate change due to high temperature. High temperature during the reproductive growth period decrease pod, seed weight in soybean. This study was conducted at National Institute of Crop Science (NICS) during the growing season. The objective of this study was to determine the effect of high temperature on growth and seed yield responses of soybean varieties using a temperature gradient chamber (TGC). In 2017, the Daewonkong (DWK), Pungsannamulkong (PSNK), and Deapungkong (DPK) were grown in three TGCs. Four temperature treatments, Ta (near ambient temperature), Ta+1 (ambient temperature+$1^{\circ}C$), $Ta+2^{\circ}C$ (ambient temperature+$2^{\circ}C$), $Ta+3^{\circ}C$ (ambient temperature+$3^{\circ}C$), $Ta+4^{\circ}C$ (ambient temperature+$4^{\circ}C$), were established by dividing the rows along which the temperature gradient was created. In all three cultivars, beginning bloom (R1) delayed at elevated temperature in $Ta+4^{\circ}C$. In addition, the days to beginning of seed fill and maturity were longer under higher temperature. The numbers of pod, 100 seed weight, and seed yield increased at elevated temperature in DWK. In contrast, seed yield components of PSNK and DPK were reduced in $Ta+4^{\circ}C$. The results suggest that 100 seed weight and seed size of soybean was low by increased temperature in $Ta+4^{\circ}C$ of PSNK and DPK.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.150-150
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• 2022

Plant reproduction associated with crop yields is highly vulnerable to global climate change components such as high and cold temperatures. The objectives of this study were to determine the effects of season-high exposure to temperature treatments in pollen morphology on Adzuki bean (V. angularis) and Mung bean (V. radiate). V. angularis and V. radiata were treated at high temperatures in the high temperature gradient greenhouse designed to cause temperature deviation. The pollen shapes treated at high temperature were compared by an electron scanning microscope. As a result, it was confirmed that the number of abnormal pollens morphology at high temperature was the least in V. radiata, and V. angularis was vulnerable to high temperatures. Also, it was found that the number of abnormal pollen morphology atT4 (Con +5~6℃) varied according to the cultivars of V. angularis. Therefore, the differences in Vigna species or cultivars with thermo-tolerance in pollen morphology to high temperature are projected to occur in the changeable future climate.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.51-51
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• 2023

Global warming has significant effects on the growth and development of wheat and can cause a reduction in grain yield and quality. Grain quality is a major factor determining the end-use quality of flour and a reduction in quality can result economic losses. Therefore, it is necessary to study the physiological characteristic of wheat to understand its response to temperature elevation, which can aid in the development of strategies to mitigate the negative effects of high temperature and sustain wheat production. This study investigated the effects of elevated temperature on grain characteristics and quality during the grain filling period of two Korean bread wheat cultivars Baekkang and Jokyoung. These two bread wheat cultivars were subjected to an increasing temperature conditions regime; T0 (control), T1 (T0+1℃), T2 (T0+2℃) and T3 (T0+3℃). The results showed that high temperature, particularly in T3 condition, caused a significant decrease in the number of grains per spike and grain yield compared to the T0 condition. The physical properties, such as grain weight and hardness, as well as chemical properties, such as starch, protein, gluten content and SDSS, which affect the quality of wheat, were changed by high temperature during the grain filling period. The grain weight and hardness increased, while the grain size not affected by high temperature. On the other hand, amylose content decreased, whereas protein, gluten content and SDSS increased in T3 condition. In this study, high temperature within 3℃ of the optimal growth temperature of wheat, quantity properties decreased while quality-related prosperities increased. To better understand the how this affects the grain's morphology and quality, further molecular and physiological studies are necessary.