This study was carried out to determine the economic injury level of the rice leaffolder, Cnaphalocrocis medinalis G.. The damage aspects of rice plant (at tilling stage) by leaf folders at different larval density per plant were studied in pot experiment (24 ㎝ in diameter, 18 ㎝ in height). One leaf folder consumed 6-7 leaves during larval stage. The damage by leaf folders was simulated by cutting off 0, 10, 30, 50, 70, and 90% of leaves before and after heading stage July 15th (at panicle initiation stage) and August 15th (at milk stage), respectively. When leaves were cut before the heading of rice, the linear relationships between the leaf cutting rate (X) and each factors of yield (Y) were as following, for grain maturity it was Y = -9.379X + 83.630 (R² = 0.493), Y = 0.139X + 0.490 (R² = 0.925) for yield, and Y = -4.880X + 81.116 (R² = 0.665) for head rice. When leaves were cut after the beading of rice, it was Y = -23.014X + 83.589 (R² = 0.915) for grain maturity, Y = 0.141X + 3.466 (R² = 0.842) for yield, and Y = -13.795X + 81.964 (R² = 0.898) for head rice. We found that when leaf cutting after the heading stage caused more damage than before the heading in terms of yield and yield components. Based on theses results the economic threshold level was estimated to be 30% and 7% leaf loss before and after heading stage.

익산지역에서 벼 줄점팔랑나비(Parnara guttata)는 1년에 3세대를 경과하며, 5월중 하순부터 월동처에서 우화하여 논으로 이동한 다음 벼 잎에 산란하기 시작하였다. 유충에 의한 벼의 피해는 7월 하순부터 증가하여 8월 중 하순 사이에 가장 많은 것으로 관찰되었으며, 3세대 성충이 우화하기 시작하는 시기는 9월 중순이었다. 벼의 이망시기와 줄점팔랑나비에 의한 피해는 만식한 논에서 켰다. 살충제를 유충발생 최성기 약 1주일 전인 7월 하순에 처리하였을 때 91.2%의 방제효과를 나타낸 반면 8월 초순에 처리할 경우에는 방제효과가 57.2%로 낮았다.

충북지역에서 벼먹노린재(Scotinophara lurida)에 대한 월동처와 본논발생에 대하여 1999년부터 2001년에 걸쳐 조사하였다. 벼먹노린재 월동성충은 월동처에서 6월 상순부터 7월 상순까지 유아등에 포획되었으며, 이동최성기는 6월 하순이었다. 본논에서 각 태별 발생 피크는 월동성충이 7월 중순, 알이 7월 하순, 약충은 8월 중순에 가장 높은 밀도를 보였으며, 제 1대 성충은 9월 중순에 가장 높은 밀도 피크를 보였다. 월동태는 성충이며, 월동충은 산기슭, 제방, 논뚝에서 발견되었다.

우리나라 남부지방에서 벼 기계이앙 및 직파재배에 따른 수도 주요해충의 발생피해를 조사한 결과, 끝동매미충, 혹명나방은 기계이앙답에서 다소 많은 발생을 보였으나 벼멸구, 애멸구는 직파재배답에서 더 많은 밸생을 보였다. 그리고 이화명나방, 흰등멸구, 벼줄기굴파리는 그 차이를 인정하기 어려웠다. 조사 해충 모두 기계이앙이나 직파재배보다는 재배시기가 발생 피해에 더 큰 영향을 주었다. 벼멸구, 흰등멸구, 애멸구, 끝동매미충은 재배시기가 늦을수록 발생량이 많았으나, 이화명나방과 혹명나방은 그 시기가 빠를수록 발생피해가 컸다.

우리나라 남부지방에서 벼 이앙시기 및 시비수준과 주용해충 발생치해와의 관계를 조사한 결과, 조사해충은 모두 시비수준보다 이앙시기가 발생 피해에 더 큰 영향을 주었다. 특히 벼멸구 흰등멸구, 애멸구, 끝동매미충, 벼물기굴파리는 이앙시기가 늦을수록 발생량이 많았으나, 이화명나방, 혹명나방은 이앙시기가빠를수록 발생량도 많았고, 피해도 컸다. 그리고 끝동매미충과 이화명나방을 제외한 해충들은 이앙시기가 늦으면서 질소질비료가 많으며 발생량이 증가하는 경향이었다.

수도포장과 휴반에서 발생하는 노린재종의 분포와 반점미 발생 관계를 조사한 결과를 휴반에서 총 21종의 노린재가 채집, 분류되었으며, 그중 우점종은 가시점둥글노린재, 긴날개쐐기노린제였고, 수도포장에서는 11종이 동정되었으며 우점종은 긴날개쐐기노린재, 설상무늬장님 노린재, 가시점동글노린재이었다. 노린재 종별 반점미 발생율은 가시점둥글노린재가 가장 심하여 34.7%였고 그 다음은 붉은잡초노린재로 2.7%였다. 노린재가 주로 벼의 유숙기를 중심으로 출수기에서 황숙기에 피해를 주었을 때 반점미 발생이 많았고, 품종별로는 극조생 또는 조생종 품봉인 태백벼, 소백벼, 삼강벼 등에서 심하였다. 지역별 반점미 발생은 조생종 품종이 재배되는 포천등 내장산간지에서 많았다.

벼잎선충(線蟲)에 대(對)한 종자소독(種子消毒) 효과 및 본답(本畓)에서의 약제방제(藥劑防除) 체계(體系)를 구명(究明)코자 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 벼잎선충(線蟲)에 대(對)한 종자소독용(種子消毒用) 살충제(殺蟲劑)로 메프유제(乳劑), 다수진유제(乳劑), 펜치온유제(乳劑)의 약효(藥效)가 양호(良好)하였다. 2. 기존(旣存) 종자소독용(種子消毒用) 살균제(殺菌劑)인 베노람수화제(水和劑), 티시엠유제(乳劑), Proaz유제(乳劑)와 살충제(殺蟲劑), 메프유제(乳劑), 펜치온유제(乳劑), 다수진유제(乳劑)를 각각(各各) 혼용(混用)하여 종자소독(種子消毒)을 하였을때에도 약효(藥效)가 우수(優秀)하였으며 약해(藥害)도 없었다. 3. 본답(本畓)에서의 벼잎선충(線蟲)에 대(對)한 방제체계(防除體系)로는 종자소독(種子消毒)+카보입제(粒劑) 토중처리(土中處理)와 종자소독(種子消毒)+카보입제(粒劑) 6월하순(月下旬) 수면처리(水面處理)가 효과적(效果的)이었다.

논에 서식하는 거미의 밀도를 조사하기 위해 1975년 11월 4일부터 11일 사이에 전북지방의 답작지대에서 의 면적내에 서식하는 거미를 채집하여 다음과 같은 결과를 얻었다. 1. 늦가을 논에 서식하는 거미의 우점종은 황갈애접시거미 (Gnathonarium dentatum), 황산적거미(Piratasubpiraticus), 혹황갈애접시거미(Gnathonarium gibberum), 등줄애접시거미(Oedothorax insecticeps)이다. 2. 단위면적당의, 평균서식밀도는 이리에서 125 마리, 진안 102마리, 부안 133마리, 대장 58마리였다. 3. 논거미로서 혹황갈애접시거미 (Gnathonarium gibberum), 착살가랑잎꼬마거미 (Enoplognatha japonica), 톱니애접시거미(Erigone prominens), 혹갈애접시거미(Erigonidium graminicola) 여덟점꼬마거미(Theridion octomaculaculatum) 들늑대거미 (Lycosa pseudoannulata), 가는줄맛거미(Dolomedes angustivirgatus) 등의 7종이 추가되어 우리나라의 논거미는 55종이 된다.

The physicochemical properties of soil and the yield and quality of rice (Oryza sativa L. cv. Sailmi) were assessed using Italian ryegrass (Lolium multiflorum Lam. cv. Kowinearly)-rice double cropping systems in the paddy fields at Goseong and Miryang in southern Korea. The average temperatures during the ripening period were approximately 1 °C higher than the optimal temperature for rice ripening and the sunshine duration was reduced by frequent rainfall. Consequently, it was slightly below the optimal conditions required for rice ripening. In the soil at Goseong, winter Italian ryegrass cropping increased the pH, electrical conductivity, and the contents of organic matter, total nitrogen (T-N), available P2O5, K, Ca, and Mg than winter fallowing. Particularly, the contents of T-N and available P2O5increased significantly. In the soil at Miryang, Italian ryegrass slightly increased the electrical conductivity and the T-N, Mg, and Na contents. Therefore, winter Italian ryegrass cropping improved the physicochemical properties of paddy soils; however, Italian ryegrass-rice double cropping slightly reduced the culm length at both Goseong and Miryang, without markedly changing the panicle length or number compared to fallow-rice cropping. Furthermore, at Goseong, Italian ryegrass-rice double cropping slightly decreased the spikelet number and milled rice yield, and increased the ripened grain rate; however, at Miryang, contrasting results were observed. In addition, fallow-rice cropping revealed no differences in the head rice or opaque rice rates. The protein content was slightly increased in Italian ryegrass-rice double cropping, without significant changes in the amylose content or Toyo value, compared to that in fallow-rice cropping. The peak and breakdown viscosities were slightly decreased. These results indicate that winter Italian ryegrass cropping might alter rice taste but may not exhibit remarkable negative effects on rice cultivation. Therefore, Italian ryegrass-rice double cropping system is recommended for paddy fields in southern Korea. Nevertheless, to increase the rice yield and quality, fertilization standards for rice cropping that consider the changes in the T-N and organic matter contents in paddy fields caused by winter Italian ryegrass cropping need to be established.

Statistical analysis was carried out to identify the influence on environmental factors between paddy water chemical properties and Chl-a concentration (algae biomass index) using water samples collected in June for 3 years at rice paddy field. As a result of correlation analysis, there was a significantly negative relationships in DO(-0.366) and pH(-0.141). In contrast, significantly positive relationships were founded in COD(+0.431) and TOC(+0.422). According to the result of factor analysis, 3 factors were obtained and indicated that PC1 were Ca, K, Mg cation, PC2 were TOC, T-P, PO4 3--P and DO, and PC3 were T-N and NH4 +-N. As a result of linear regression analysis to develop a prediction model for chl-a concentration, the total amount of explanation was 20.6%, PC2 had the greatest influence on the increase of chl-a concentration and PC1 also showed a positive correlation but the PC3 has a negative correlation. In conclusion, carbon and phosporous content are the main factors for the increase algae blooms of rice paddy.

The application of animal manure on farm fields is one of the most economical ways. However, the continuous application of manure in paddy fields might change soil properties influencing the growth of rice plant. Thus, this study was conducted to investigate the changes in selected chemical and biological properties of soils and rice production as affected by the applications of two different fertilizer sources, which were the consecutive applications of liquid swine manure (LSM) and chemical fertilizer (CF), during the three experimental years, from 2012 to 2014. Application amount of LSM was based on 100% of nitrogen fertilizer recommendation rate for rice cultivation estimated by soil testing. Plant height and tiller number in rice at the first year of liquid swine manure manure plot were lower than those of chemical fertilizer plot. Height and tillers of rice in liquid swine manure plot were higher than those of rice in chemical fertilizer plot after consecutive application for 3 years. Rice yield In the first year of application was decreased by 7% than that of chemical fertilizer, but the yield of rice in the third year of application in LM 100% plot was increased by 8% compared to the chemical fertilizer. Toyo-taste value of milled rice in LM 100% was decreased by increasing of protein contents and decreasing rate of perfect grain. The K and Zn contents in the soil were increased in the plots of consecutive LSM application. The results implied that the liquid manure may neither decrease the yield of rice and nor increase soil properties except K and Zn in the soil, and decrease rice quality.

Drought caused by global climate change is one of serious problems for rice cultivation. However, it was little reported the impact of drought on rice cultivation in Korea. In here, to assess impact of drought on rice varieties in Korean climate condition, growth characteristics and yield components of rice were compared on irrigated and partially irrigated rice paddy field. First, we have chosen 11 rice varieties including ‘Saeilmi’ and ‘Shindongjin’ which are widely cultivated in Korea. For partially irrigated rice paddy treatment, we have withheld irrigation from 25 days after transplanting and water supply was totally dependent on rainfall for rice cultivation. When we examined early plant height and tiller number of these varieties on partially irrigated rice paddy were reduced 1.6% to 18.4% and 10.4% to 33.1%, respectively, and these reduction rate were highly correlated with yield loss in our experimental conditions. Among rice yield components, panicle number was decreased 10.5% to 30.1% according to rice varieties and reduced panicle number was highly correlated with yield loss. Grain number per panicle, grain filling rate and 1,000 seeds weight did not have correlation with yield loss of rice varieties. These result means that growth stage, especially the tillering stage, is seriously affected by drought on rice cultivation in Korea. And we suggest that ‘Saeilmi’, ‘Ilmi’ and ‘Ilpum’ are good for rice cultivation on drought prone rice field in Korea.

The Arabidopsis gene AVP1 encodes a vacuolar H+-translocating inorganic pyrophosphatase (EC3.6.1.1) that functions as an electronic proton pump in the vacuolar membrane and affects growth development and stress responses in plants. This study was conducted to evaluate the molecular properties of the A. thaliana vacuolar H+-pyrophosphatase (AVP1) gene in rice. Incorporation and expression of the transgene was confirmed by PCR and quantitative real-time PCR, respectively. Expression of the AVP1 gene in transgenic rice plants (TRP1 and TRP2) resulted in significantly enhanced tolerance to 100 mM NaCl under greenhouse conditions when compared to control wild-type (WT) rice plants. Augmented AVP1 expression in the transgenic rice plants also affected total biomass and improved ion homeostasis through increased accumulation of Na+ ions in whole tissues when compared to control WT rice plants under high salinity conditions. The Fv/Fm values of transgenic rice plants were higher than those of WT rice plants, even though the values decreased over time in both WT and transgenic (TRP1 to TRP8) rice plants. Furthermore, rice grain yield and biomass of the transgenic rice plants were at least 15% higher based on the culm and root weights and panicle and spikelet numbers when compared to those of the WT rice plants during the farming season in Korea. Thus, these results suggest that ectopic AVP1 expression conferred tolerance and stress resistance to genetically modified transgenic crop plants by improving cellular ion homeostasis against salt conditions, which enhanced the rice yield and biomass under natural conditions in paddy fields.

연구는 간척지에서 사료용벼를 재배하여 조사료를 생 산함으로써 간척지 이용률 증진과 조사료생산의 두가지 가 능성을 검토해보고자 일반답과 간척답에서 사료용벼를 재 배하여 생육특성, 총체수량 및 사료가치 등을 조사하였다. 1. 출수기는 일반답에서 8월15일에서 8월30일, 간척답에 서 8월14일에서 8월 29일이었으며, 간척답이 일반답 보다 1~2일 빨랐으며, 목우는 일반답에서 8월 26일, 간 척답에서 8월 27일로 수원 544호를 제외하고는 가장 늦었다. 2. 초장은 일반답에서 105~135 cm범위이었고, 간척답에 서 97~126 cm범위였으며 일반답에서는 목양이 간척 답에서는 수원544호가 가장 컸다. 주당경수는 일반답 과 간척답 모두 녹양이 16개로 가장 많았고 총체수량 은 일반답은 15.26~23.24 MT ha-1, 간척답은 11.94~18.89 MT ha-1범위이었으며 목우벼가 두지역에서 가장 많이 생산되었다. 각품종별 수량은 일반답에 비하여 78~84% 수준이었다. 3. 단백질 함량은 일반답에서는 녹양벼가 높았으나 간척 답에서는 6.7~8.7%로서 상대적으로 낮은 수치를 보였 고 목양벼가 8.7%로 가장 높았다. 각 품종별 NDF는 31.2~55.5% 수준을 나타냈으며 ADF는 일반답에 비 하여 큰 차이를 보이지 않았으며 가소화 양분총량을 계산해본 결과 일반답에서 목우벼가 71.2%로 가장 높 았고 전체적으로 60%이상의 함량을 보여 간척지에서 재배하여도 사료로서의 가치는 충분할 것으로 생각되 었다. 4. TDN수량을 비교해본 결과 일반답에서 TDN수량은 목우벼가 16.54 MT ha-1로 가장 높았으며 간척답에서 도 12.69 MT ha-1 로 가장 높은 수량을 보였다. 5. 이상의 결과로 간척지에서 사료용벼를 재배할 경우 일 반답에 비하여 80%정도의 수량을 보여 간척지에서 재 배가능성을 확인하였으며 목우를 재배할 경우 수량 및 사료가치면에서 가장 좋을 것으로 생각된다.

Lodging in the direct seeded rice cultivation on flooded paddy is being severe problem due to the lower production and grain quality at ripening stage. This study was conducted to examine the effect of Iprobenfos-metconazole (IPM) treated 50, 40 and 30 days before heading respectively as a plant regulator to reduce the lodging at ripening stage of direct seeding rice cultivation. The culm length treated with IPM, especially the 4th culm internode, was shortened more than with untreated plot, and the most effective time was at 30 days before heading. At 20 days after heading the flag leaves colour showed more greening than in the untreated leaves and the plot with IPM treatment was to be maintained longer compared to the control plot. The Nitrogen concentration of leaves with IPM was lower than in the control plot, and SiO2 contents were higher than in the untreated plot and SiO2/N ratio was increased more in the IPM plot than in the control plot. The breaking strength of 3rd and 4th culm internode with IPM treatment was higher than in the untreated plot, and the lodging index was reduced in the IPM plot significantly and the field lodging also was reduced. As the results the rice production in the IPM plot was increased more due to be higher ripening ratio and seed grain weight compared to the untreated plot to be occurred the field lodging.