사질계(砂質系) 답토양(畓土壤) 유형별(類型別)로 질소(窒素), 인산(燐酸), 가리(加里) 및 Bentonite와 Zeolite를 동시(同時)에 전량전층시용(全量全層施用)이 수도생육(水稻生育)고 수량(收量) 및 토양개량(土壤改良) 효과(效果)에 미치는 영향(影響)을 포장(圃場) 시험(試驗)하였다. 수도수량(水稻收量)은 삼요소(三要素) 전량전층시용(全量全層施用)에 비(比)해 삼요소(三要素)와 점토광물(粘土鑛物) 동시(同時) 전량전층(全量全層) 시용(施用)이 증수(增收)되었는데 사양토(砂壤土)에서는 Zeolite 1.0 M/T, 사토(砂土)에서는 Bentonite 0.5 M/T, 시용(施用)이 각각(各各) 5%수준(水準)에서 유의성(有意性)이 있었고 사토((砂土)에서 Bentonite 1.0 M/T 시용(施用)은 1% 수준(水準)에서 유의증수(有意增收)되었다. 출수기(出穗期) 수도경엽중(水稻莖葉中)의 양분함량(養分含量)은 삼요소(三要素) 전량전층시용(全量全層施用)에 비(比)해 삼요소(三要素)와 점토광물(粘土鑛物)을 동시(同時)에 전량전층시용(全量全層施用)함으로써 질소(窒素)와 규산함량(珪酸含量)은 높아졌고 인산(燐酸) 및 염기(鹽基)의 함량(含量)도 증가(增加)하는 경향(傾向)이었다. 또 토양(土壤)의 pH와 염기치환용량(鹽基置換容量)은 다소 높아졌고 유효규산(有效珪酸) 및 치환성염기(置換性鹽基)의 함량(含量)이 증가(增加)하였다.

포장조건하에서 수잉기와 출수기에 벼멸구를 인위적으로 가해시킨 후 출수후 고사시기별로 수량수율을 조사하여 다음과 같은 결과를 얻었다. 1. 출수후 23일경에 고사된 벼는 무접종구에 비하여 등숙율은 현미천립중은 감소되었다. 2. 고사시기가 같아도 수잉기부터 가해구는 출수기부터 가해구보다 등숙율 현미천립중, 현미수량이 낮았다. 3. 고사된 벼의 감수율은 무접종에 비하여 고사시기에 따라 였으며 출수후 고사일수(X)와 수량(Y)간에는 다음과 같은 관계가 있었다. o 수잉기이후가해 : o 출수기이후가해 : .

자연조건하에서 인위적으로 접종시킨 벼멸구가 증식하였을 때, 벼의 생육단계별 벼멸구피해가 수량에 미치는 영향을 조사하여 다음과 같은 결과를 얻었다. 1. '81년의 경우 출수기이후 방제구의 수량은 최고 분얼기, 수잉기, 완전방제구에 비하여 수량감소현상이 있었고, '82년의 경우느 수잉기 방제구부터 수량감소 현상이 나타났다. 2. 벼멸구 제1세대 개체군에 의한 초장과 경수에의 영향은 없었으나 벼멸구 제2세대, 3세대 개체군에 의한 천립중과 등숙율에의 영향은 수량감소의 결과로 나타났다. 이 영향은 특히 출수후부터 유숙기 까지의 벼멸구 개체군(제 2세대 개체군)과 상당한 관계가 있었으며 다음과 같은 회귀방정식을 구하였다. 3. 충접종후 수확시까지의 벼멸구 개체군에 수당총밀도(X)와 수량(Yg)과의 관계는 였다. 4. 벼멸구 대발생의 근원은 비래후 제1세대에 있은 고로 이 세대의 밀도, 연령구성, 시형, 기타의 개체군 특성에 관한 지식은 해충 방제의 합리화를 위한 기초가 된다.

1981년 영남내륙지방에 심하게 발생된 벼 검은줄무늬오갈병의 이병포장에서 초장위축율에 따른 수도생육 및 수량구성요소의 변화를 조사한 결과는 다음과 같다. 1. 위축이 심할수록 간장 및 수장이 현저히 감소하였다. 2. 건전주에 비하여 이병주는 토위절간의 감소율이 크고, 3절간 및 4절간의 상대적으로 위축율이 감소되는 경향이었다. 3. 위축이 심할수록 수량구성요소 및 수량은 현저히 감소되었으며, 이상 위축되면 수량은 개무상태가 되었다. 4. 위축율과 수량과의 관계식은 청청벼에서 , 낙동벼는 로서 검은줄무늬오갈병에 이병되면 지수함수적인 수량감소가 확인되었다.

시험은 흰빛잎마름병의 품종별 감수성과 수량 및 품질에 미치는 영향을 구명코자 시비량을 보비재배와 다비재배로 구분하여 전남지역에서 수행 되었다. 흰빛잎마름병은 발생은 다비조건에서 심했으며 심한 발병은 수도 품종들의 등숙에 영향을 주어 수량 감수를 초래하였고 청미율은 품질을 저하 시켰다. 또한 조생계품종에서는 지엽과 차엽이 발병되었지만 중, 만생계품종에서는 지, 차, 삼엽이 발병되었다. 이러한 차이는 보비조건에서 보다 다비조건에서 더욱 뚜렷하였다. 이 병에 대한 저항성품종은 태백벼, 백운찰벼, 팔공벼, 밀양 42호이었고 밀양 30호, 금강벼, 낙동벼, 진주벼는 감수성이었으며 이러한 경향은 시비 수준간에 같은 경향이었다.

초 록 벼이삭 선충의 피해를 구명코저 접종시험을 실시하였다. 1. 선충의 기생은 벼의 생육 특히 분얼수에 많은 영향을 주었다. 2. 피해경율은 온도 상승과 더불어 증가하여 출수후에는 약 3배로 늘었다. 3. 생육 및 수량에 영향을 줄 수 있는 피해경율은 이상이다. 즉 피해발현 초기에 이하일 때는 생육과 수량에 영향이 없었고 일때 이면 의 감수를 초래하였다. 4. 수량구성요소별로는 1000립중 립수 수수의 순으로 영향을 받았다.

시비량의 증시에 따라 수량은 증가하지만 어느 일정수준 이상 과용하던 병충해발생을 유발하여 수량의 감소를 초래하므로 시비량을 현행수준 보다 올리는 반면 병충해 방제를 강화하여 병충해피해를 줄이고 최대한의 증수를 가져 올 수 있는 적정시비수준과 병충해 방제효과를 구명하고자 본 시침을 실시하여 다음과 같은 결과를 얻었다. (1) 잎도열병, 이삭도열병 발병율은 다 같이 시비량과 수준에서 높은 정(+)의 상관을 나타내었고 인산과 가리를 과용하면 삼요소 표준구보다 발병이 훨씬 많았다. (2) 병충해방제를 실시하지 않을 때는 시비량을 질소기준 8-8.5kg/10a 시용하였을 때 347-378kg/10a의 최고현미수량을 얻었는데 비하여 병충해방제를 실시하면 질소기준 18.5-19kg/10a수준에서 453-462kg/10a의 최고수량을 나타내었고 병충해방제 실시여부에 따른 수량의 차이는 평균 100kg/10a을 상회하였다. (3) 질소비료만 증시한 구와 삼요소비료를 동시에 증시한 구 사이의 수량에 미치는 영 향은 유의 차가 없었다. (4) 현미수량지수로 환산한 병충해탕제효과는 최고 에서 최저 까지 나타났으며 평균방제효과는 였다.

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.

본 연구는 벼 품종에 따른 미음 가공특성을 구명하기 위하여 국립식량과학원에서 육성한 9개 벼 품종의 호화점도 특성과 미음의 색도, pH, 점도 및 퍼짐성을 측정하고, 초미세구조를 관찰하였다. 신속점도계를 이용한 호화 점도(페이스팅) 분석에서, 치반점도는 한아름4호, 화선찰이 각각 -45.84 및 -27.50 RVU, 최종점도는 화선찰, 한아름4호가 각각 109.00, 213.42 RVU로 미음죽의 노화가 다른 품종들에 비해 느릴 것으로 판단된다. 쌀 낟알과 미음의 미세구조를 주사현미경(SEM)으로 관찰하였는데, 쌀알은 다각형의 전분립으로 구성된 구 형태의 전분체와 이러한 전분체로 구성된 전분세포로 구성되어 있었다. 도담쌀은 구 모양의 전분체가 관찰되었고 다른 품종들에 비해 빈 공간이 더 많았으며, 한아름4호는 일반 멥쌀의 형태와 같은 다각형의 전분립을 확인하였고, 화선찰벼는 전분체를 구성하는 전분립들의 부서짐이 많은 것을 관찰하였다. 그리고 이 품종들로 만든 미음죽 호화양상은 품종별로 달랐는데 이는 주로 아밀로오스 함량 차이에 기인하는 것으로 판단되나, 같은 고아밀로오스 품종이라 하더라도 도담쌀에 비해 고아미4호는 잘 풀어지고 호화가 잘 되는 것으로 나타나는 바(data not shown), 이에 대한 추가적인 연구가 필요하다 하겠다. 품종별 미음 제조 후, 관능검사에서 통일형(초다수성) 벼품종과 자포니카 벼 품종들의 차이가 뚜렷하게 나타나지 않아 초다수성 벼 품종으로 자포니카 벼 품종을 대체할 수 있을 것으로 판단하였다(data not shown). 또한 아밀로오스 함량 차이에 따른 벼 품종들 간의 점도 차이가 확연하게 나타났는데 아밀로오스가 없는 찰벼 품종은 미음죽의 점도를 낮추고, 고아밀로오스 품종들은 미음죽의 점도를 높였다. 통일형(초다수성 벼)을 포함한 일반메벼 품종들의 점도는 찹쌀과 고아밀로오스 품종들로 만든 미음의 중간정도를 보였으며 품종간의 유의한 차이는 없었다. 요컨대, 통일형 품종은 일반쌀 품종에 비해 밥용으로 식미가 나쁜 것으로 알려져 있으나, 미음에 대한 가공적성 평가 결과, 통일형쌀 품종과 일반쌀 품종 간에 품질 차이가 없었다. 쌀미음의 점도와 퍼짐성은 쌀미음의 품질을 결정하는 중요한 요소이며 9개 품종(통일형 4개 품종, 일반형 5개)의 쌀미음 가공적성을 평가한 결과, 고아밀로오스(31.8%-42.8%) 쌀 품종들은 점도가 높아(낮은 퍼짐성) 걸쭉하였고, 저아밀로오스(5.0%)인 찹쌀 품종은 낮은 점도(높은 퍼짐성)로 유동적이었다. 중간정도의 특성을 가진 멥쌀(18.2%-19.9%) 품종들이 쌀미음에 적합한 것으로 나타났다. 멥쌀 품종들 중에서 생태형(통일형/일반형)에 따른 쌀미음의 점도와 퍼짐성에서 차이가 없었다.

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely ‘top quality rice’) cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. ‘Hiami’ showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: ‘Younghojinmi’ and ‘Mipum’ in Daegu, ‘Daebo’, ‘Samgwang’, Chilbo’ and ‘Younghojinmi’ in Gumi, ‘Samgwang’, ‘Jinsumi’ and ‘Sukwang’ in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions.

The study was carried out to determine the changes of growth characteristics, anthocyanidin, and brown rice yield grown at coast and inland areas apart from the east coastline of Gyeongsangbuk-do province. Number of spikelets per panicle was much more increased in inland area. Regional difference in number of spikelets per panicle was observed in Jeongjinju cultivar. Among these red rice cultivars, the highest brown rice yield was Jeongjinju rice cultivar having 702 ㎏ in inland area and 692 ㎏ in coast area, respectively. Anthocyanidin content ranged 524 to 610 ㎍/g dry weight basis. Cyanidin content was 11.4 to 14.0 times higher than that of delphinidin under coast and inland area. Anthocyanidin content was higher in rice cultivar grown at coast area. Highest head brown rice rate was only observed in Geonganghongmi to 95.2 at coast area and 95.4 inland area. In considering brown rice yield and pigment content, Hongjinju rice cultivar was recommended in optimal pigment rice cultivar in eastern coast of Gyeongsangbuk-do Province.

친환경 벼 재배농가에서 혼합유박비료를 관행적으로 이앙 3일 전에 사용함에 따라 분얼 기 이후에 비료효과가 나타나므로 수량이 감소하는 문제를 해결하기 위해 본 연구를 수행 하였다. 실내에서 조사한 혼합유박비료의 무기화는 담수조건에서 7주까지 NH4-N가 증가하 였고, 비담수 조건에서 5주까지 NO3-N가 증가하였다. 벼 이앙 20일에 논토양의 질소무기화 는 이앙 20일 전 처리구가 0.85%로 가장 높았다. 수확기 토양특성은 혼합유박비료 시비시 기에 따라 토양유기물함량을 제외하고 차이가 없었다. 이앙 60일에 초장, 간장, 수장은 이 앙 20일 전 처리구가 가장 길었다. 또한 이앙 20일 전 처리구에서 수수, 등숙비율, 천립중이 높게 나타나 백미수량이 관행처리(이앙 3일 전)에 비해 9% 증가하였다. 백미의 백도와 amylose는 차이가 없었지만, 단백질 함량과 식미치는 이앙 20일과 30일전 처리에서 같은 수 준이었다. 쌀 수량과 품질 등을 혼합유박비료 시용시기와 관계식으로 산출하면 혼합유박비 료의 적정 사용 시기는 이앙 21.3일 전으로 나타났다.

The increase in the frequency of occurrence of abnormal weather could include severe rainfall, which could cause rice submergence during the ripening stage. This experiment was conducted to clarify the effects of submergence during the ripening period on yield and quality of rice. The flooding treatment was conducted at 7 and 14 days after heading. Flooding conditions were created with two conditions, flag leaf exposed and overhead flooding, and each condition was divided into two conditions according to water quality—clear and muddy. Although the yield decrease was more severe at 7 days after heading because of the decrease in the ripening ratio, the head rice ratio was more affected at 14 days after heading because of the increase in the chalky kernel ratio. The maximum quantum yield (Fv/Fm), which indicates the photosynthetic efficiency, did not differ before and after the flooding treatment until flooding continued for 4 days. In addition, stem elongation occurred because of flooding as an avoidance mechanism in japonica rice. This phenomenon was expected to decrease the supply of assimilation products to the spikelet (sink). Overall, it was suggested that additional experiments should be conducted examining the change in the starch synthesis mechanism and transfer of assimilate products resulting from submergence, for development of cultivation techniques corresponding to submergence and breeding of varieties with submergence tolerance characteristics.

This experiment was conducted to assess changes to the chemical properties of soil and applicability in a case of rice cultivation with organic fertilizers. The investigator applied organic fertilizers to rice cultivation for five years to examine changes to the chemical properties of soil and found that the experiment group of organic fertilizers made an ongoing increase in pH, organism content, and available phosphate content annually compared with the control group with no big differences according to the amounts of organic fertilizers used. As for the yield components, there were no statistical differences in the number of spikelets and grain filling rate between the experiment group of organic fertilizers and the control group. The experiment group recorded a higher level in 1,000 seeds weight and yield than the control group. Experiment Group 4 recorded the highest level at 29.11 kg of 1,000 seeds weight. Experiment Groups 3 and 4, which used 222 kg and 267 kg per 10 a, respectively, recorded 576 kg and 572 kg of yield, respectively, which were 4.7% and 4.1% higher than 549 kg of control group, respectively. As for the quality of brown rice, there were no statistical differences in the head rice percentage between the control and experiment group, both of which were in the range of 83.2-85.7%. As for the protein content, Experiment Groups 3 and 4, both of which used a lot of organic fertilizers, were in the range of 6.9-7.1%, which was lower than 7.5% of control group. Those findings indicate that the long-term application of organic fertilizers can improve the chemical properties of soil and increase the yield more than the conventional method of fertilizer application. The findings also suggest that it will be effective to apply 222 kg of organic fertilizers or more per 10 a.

''Hyowon 5’, a new aromatic rice variety with high yield was derived from a cross between 'Dasan’ as a high yield source and ‘IR841-1-1-2’ as a donor for aroma. A general pedigree breeding method was applied to develop Hyowon 5. In F8 generation, a promising line, JS14-12-36-8-5-3-1-1-1, was selected and designated as the name of ‘SP 102’ in 2012. This variety headed on Aug. 14 , which is 3 days later than ‘Hwayoung’ in middle plane. The brown rice of this aromatic variety ‘Hyowon 5’ exhibited 51 odor-active volatiles including a pop corn-flavoring 2-acetyl-1-pyrroline which is exclusively detected in aroma rice varieties. The Culm length and panicle length of this variety was 83.2 cm and 26.4 cm, respectively. This variety has about 14.9 tillers per hill and 124.5 spikelet numbers per panicle. The 1000-grain weight was 20.9 g in brown rice. The yield performance of brown rice was 6.27 MT/ha in local adaptability test.

Recently, rice growth and production have been influenced by climatic change worldwide. In particular, under low solar radiation and cloudy weather, rice plants show abnormal physiological responses. In this experiment, plants of the rice cultivar Samgwangbyeo grown 40% and 70% shading and natural conditions at the primordium initiation stage (PI) for 30 days and the booting stage for 10 days up to heading were compared. After shading treatments, culm lengths were significnatly longer than that in natural condition plots, and panicle lengths were shorter in the 40% and 70% shading treatment plots compared to control plots. After heading, the production of dry matter treated at the PI stage was significantly lower than that at the booting stage. SPAD values of the leaf color and N concentration of leaves treated with shading were greater than those under natural conditions. In the shading treatment, the lodging index at 20 days after heading was significantly higher than that in natural condition. For yield components, number of panicles, spikelet number per panicle, and ripened grain ratio significantly decreased with shading treatment; thus, rice yield decreased significantly. For rice quality, the protein content of the head rice treated with shading was significantly higher than that in the control plot, but the amylose content of rice treated with shading was signifiantly lower than that in rice in control plots.

The late-maturing black rice cultivar Shinnongheugchal from Jeollabuk-do Agricultural Research and Extension Service was used as the plant material for estimating growth characters, quality and yield from the vegetation period to harvest age. This study was performed to select an optimum combination of nitrogen level and planting density for the maximum yield of Shinnongheugchal. The plant height, number of tillers, and SPAD index were higher when the combination of 70 hills per 3.3 m 2 and 13 kg/10 a nitrogen level was used at 30 days after transplanting. The heading date for the combination of 70 hills per 3.3 m 2 and 15 kg/10 a nitrogen level, and 80 hills per 3.3 m 2 and 15 kg/10 a nitrogen level was August 22. The heading date for the other combinations was August 21. The combination of 70 hills per 3.3 m 2 and 13 kg/10 a nitrogen level yielded the highest number of tillers at 40 days after flowering. Even though the lodging index was increased with increasing nitrogen levels, field lodging did not occur until harvest time. Seed nitrogen concentration in the combination of 70 hills per 3.3 m 2 and 13 kg/10 a nitrogen level showed a significant difference when compared with the other combinations. The black rice yield varied significantly, and the highest yield was observed in the combination of 70 hills per 3.3 m 2 and 13 kg/10 a nitrogen level. The yield was significantly correlated with seed nitrogen concentration. The maximum yield was estimated to be 14.67 kg/10 a nitrogen level by using the regression equation. On average, the coloring degree of the black rice was higher at planting density of 70 hills per 3.3 m 2 than at 80 hills per 3.3 m 2 . The highest yield of perfect black rice was obtained using the combination of 70 hills per 3.3 m 2 and 13 kg/10 a nitrogen level. Our findings demonstrate that a nitrogen level of 13-14 kg/10 a can be used to obtain the maximum yield from Shinnongheugchal with yield, cyanidin 3-glucoside content, and perfect black rice yield as the standard.

A long-term field experiment under different fertilization treatments had been conducted to explore the effects of rice yield and soil chemical properties from 1978 to 2008 in Suwon, Korea. The paddy was applied eight fertilization treatments which were F0 (no fertilizer), PK (phosphorous and potassium), NK (nitrogen and potassium), NP (nitrogen and phosphorous), NPK (nitrogen, phosphorus and potassium), NPKC (NPK with compost), NPKS (NPK with straw) and NPKL (NPK with lime). Results of 31 years experiment showed that yield index (the ratio of yield in each treatment to NPK) was the lowest in F0 (0.52) and the highest in NPKC (1.18). Yield index was gradually increased in NPKC but decreased in F0 and NK. The yield index of PK, NP, NPKS and NPKL were not changed long-term treatment. Soil acidity of NPKL showed the highest with pH 7.9, and that of other treatments ranged from pH 6.3 to 6.8. Available phosphorous content of soil was increased in all plots by long-term fertilization, was the highest in PK and NPKC. Soil organic matter was higher in NPKC (1.8%) and NPKS (1.8%) than other treatments (1.3~1.4%) in the early experiment, but that was remarkably increased in only NPKC (2.5%) according to annual long-term application. Thus we suggest that annual compost application with optimum NPK could make stable and sustainable rice production.

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.

Rural Development Administration has recently developed mid-late maturing rice cultivars with high quality. This study was conducted to select suitable mid-late maturing rice cultivar in major cultivation areas of Gangwon Province among domestic breeding cultivars for 2 years from 2013 to 2014. The average air temperature during the experiment in 2013 and 2014 was higher 0.6~1.1°C in Chuncheon, 1.0~ 1.3°C in Gangreung, and 0.1~0.7°C in Cheolwon than normal year. Precipitation in ripening period was higher 52.5 mm in 2013, but lower 176.4 mm in 2014 than normal year in Chuncheon, lower 103.1 mm in 2013 and higher 42.9 mm in 2014 in Gangreung, lower 225.9~322.7 mm in Cheolwon. Duration of sunshine in ripening period was higher 142 hours in Chuncheon, 108 hours in Gangreung, and 94 hours in Cheolwon than normal year in 2013, higher 20~21 hours in Chuncheon and Gangreung, and 82 hours in Cheolwon than normal year in 2014. Milled rice yield of ‘Samgwangbyeo’ and ‘Daebobyeo’ was 594 kg per 10a, and 578 kg for ‘Jinsumibyeo’ in Chuncheon in plain area. For Gangreung in east coastal area, the yield of ‘Daebobyeo’ was 555 kg per 10a, ‘Hopumbyeo’ was 554 kg, and ‘Chilbobyeo’ was 546 kg. For Cheolwon in mid-mountainous area, the yield was 504 kg per 10a for ‘Daebobyeo’ and 489 kg for ‘Haiamibyeo’. But there was no difference in milled rice yield among cultivars tested in the study at each area. Head rice ratio of ‘Haiamibyeo’, ‘Jinsumibyeo’, and ‘Mipumbyeo’ in Chuncheon was 94.2~95.6% higher than the other cultivars. In Gangreung head rice ratio of ‘Hopumbyeo’, ‘Haiamibyeo’, and ‘Samgwangbyeo’ were 85.2~88.3% but there was no difference among cultivars except ‘Gopumbyeo’ and broken rice ratio of ‘Haiamibyeo’, ‘Samgwangbyeo’, and ‘Mipumbyeo’ were low as 7.5~8.5% and palatability of ‘Mipumbyeo’ was higher than the other cultivars. Head rice ratio of ‘Daebobyeo’ was the highest as 89.2% and there was no difference in broken and chalky rice ratio and palatability among cultivars in Cheolwon. Considering rice yield and quality in major cultivation areas of Gangwon Province, suitable mid-late maturing rice cultivars were ‘Samgwangbyeo’, ‘Haiamibyeo’, and ‘Jinsumibyeo’ in Chuncheon, ‘Daebobyeo’ and ‘Chilbobyeo’ in Gangreung, and ‘Daebobyeo’ and ‘Haiamibyeo’ in Cheolwon. The results obtained in the study imply that the selected cultivars with high yield and quality and suitability to Chuncheon, Gangreung, and Cheolwon, respectively could be recommended to rice cultivating farmers in the regions with high priority.