Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas

개화후 강우 시기가 홍화의 생육과 종실의 품질에 미치는 영향을 구명하기 위해 시험을 수행한 결과는 다음과 같다. 개화후 강우 시기에 따른 지상부 및 꽃 봉오리 병해 발생 정도는 각각 3.3, 1로서 영향을 미치지 않았다. 등숙 비율은 주경은 개화후 1~5일 강우시 37.4%, 1차 분지는 개화후 6~10일 강우시 63.0%로서 가장 낮았다. 10a당 수량은 무강우의 327kg/10a에 비해 개화후 6~10일과 개화후 11~15일 강우시 282~281kg/10a으로서 각각 14% 감소되었다. 종실의 색도(명도=L)는 개화후 21~25일 강우시 73.5, 26~30일 강우시 69.9로서 무강우 79.3에 비해 크게 낮아졌다. 이상의 결과에서 볼때 수확기 강우에 의한 종실의 품질 손실 방지를 위해서는 개화후 25일까지는 수확을 해야 할 것으로 사료된다.

Response of grain yield and milled-rice protein content to nitrogen (N) rates at various growth stages is critical for quantifying real-time and real-amount of applied N requirement for target grain yield and protein content. An experiment including 10 N rate treatments at transplanting, tillering and panicle initiation stages with four rice cultivars in 2003, 6 N treatments with two rice cultivars in 2004 and 2005 was conducted. Increase of N rates at PIS significantly increased both grain yield and milled-rice protein content but increase of N rates at tillering stage significantly increased grain yield but not milledrice protein content. Therefore, high grain yield and low milled-rice protein content would be difficult to obtain only by adjusting N rates at PIS. Internal N use efficiency (INUE) was 60.5 kg grain/kg N accumulation on an average over N treatments, cultivars, and experimental years, showing considerable reduction especially at high shoot N accumulation in the experimental year of low sunshine duration. Milled-rice protein content tended to increase almost linearly with increasing shoot N accumulation, but it revealed big variation even at the same shoot N accumulation at harvest. Milled-rice protein content decreased with increasing INUE. N accumulation in the milled rice increased at an almost constant proportion of 45.5 percent of the shoot N accumulated at harvest, showing slight decresing proportion with the increasing shoot N accumulation.

Response of grain yield and milled-rice protein content to nitrogen topdress (N) timing at panicle initiation stage (PIS) is critical for quantifying real-time N requirement for target grain yield and milled-rice protein content. Two split-split-plot experiments with three replications, one in 2004 and the other in 2005, were conducted in Experimental Farm, Seoul National University, Suwon, Korea. The experiments included three N rates at tillering stage (TS), three N timing treatments at panicle initiation stage (PIS) and two rice cultivars. The N rates at TS, N timing at PIS, and rice cultivars were randomly assigned to main plot, sub plot, and sub-sub plot, respectively. Results showed that the delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level. The calculated optimum N timing at PIS from pooled data by N rates and rice cultivars in two years was at 28 days before heading (DBH). However, real-time of N timing at PIS was dependent on plant growth and N status around PIS that in turn was dependent on applied N rates at TS. The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 kg N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively. In general, earlier applied N at PIS resulted in lower milled-rice protein content but the highest grain yield was expected to be obtained when N topdress at PIS was applied at the time when shoot N concentration started to drop below about 23 mg/g due to dilution effect after transplanting. In conclusion, the results of our experiments imply that the currently recommended N topdress time (24DBH) at PIS in Korea should be reconsidered for the higher grain yield and the better quality of rice.

축산분뇨의 효율적인 사용을 위하여 액상구비 형태의 돈분뇨를 벼-보리 작부체계 포장에서 1년에 1회~~ 2회 시용하여 벼수량 및 품질을 조사하였다. 축산농가의 돈분뇨는 채취시기나 채취농가에 따라 질소성분이 3~~7gkg1까지 함량에 차이가 많았으며 인산, 칼리 함량도 높았다. 현미 수량은 LPM+LPM 처리구에서 14~% 로 가장 많이 증수하였으나, 다른 처리에 비하여 도복이 일어날 확률이 높고, 완전립 비율이 떨어지며 심복백율이 높아 품질이 저하될 우려가 높았다. LPM+CF, CF+LPM처리구의 수량은 CF+CF보다 약간 높았으며, 완전립율 이나 쇄미율에서는 차이가 없었다. 보리의 생육 및 수량은 처리간에 차이가 없었다. 따라서 답리작 포장에 돈분뇨는 1년에 한번 시용하는 것이 벼 수량에 양호하며 돈분뇨 시용량은 질소기준량의 70~% 가 적절할 것으로 판단된다. 또한 미숙분뇨로 인한 작물의 피해를 줄이기 위해서는 6개월 이상 부숙 시킨 양질의 액상구비를 사용하도록 주의하여야 하며, 연용 할 경우 액비의 특성을 고려하여 액비 시용량을 작물의 질소표준시비량보다 적게 사용하는 것이 좋을 것으로 사료된다

A study on genetic variability and association of yield attributing characters with grain yield was carried out using 35 deepwater rice genotypes. High genotypic co-efficient of variation (GCV) was observed for plot yield, EBT/m2 , plant height and days to 50~% flowering (DFF). For all the traits, estimates of the phenotypic co-efficient of variation (PCV) were higher than GCV, indicating presence of environmental influence. High heritability and genetic advance was observed for plot yield, EBT/m2 and plant height. Plot yield had significant positive association with test weight, EBT/m2 and DFF. However, test weight had the maximum direct effect on grain yield

A split-plot designed experiment including four rice varieties and 10 nitrogen levels was conducted in 2003 at the Experimental Farm of Seoul National University, Suwon, Korea. Before heading, hyperspectral canopy reflectance (300-1100nm with 1.55nm step) and nine crop variables such as shoot fresh weight (SFW), leaf area index, leaf dry weight, shoot dry weight, leaf N concentration, shoot N concentration, leaf N density, shoot N density and N nutrition index were measured at 54 and 72 days after transplanting. Grain yield, total number of spikelets, number of filled spikelets and 1000-grain weight were measured at harvest. 14,635 narrow-band NDVIs as combinations of reflectances at wavelength ~lambdal~;and~;~lambda2 were correlated to the nine crop variables. One NDVI with the highest correlation coefficient with a given crop variable was selected as the NDVI of the best fit for this crop variable. As expected, models to predict crop variables before heading using the NDVI of the best fit had higher r2 (>10~%) than those using common broad- band NDVI red or NDVI green. The models with the narrow-band NDVI of the best fit overcame broad- band NDVI saturation at high LAI values as frequently reported. Models using NDVIs of the best fit at booting showed higher predictive capacity for yield and yield component than models using crop variables.

Twenty-one lowland rice genotypes were evaluated for their stability parameters with respect to grain yield in a multi locational trial at five different sites of Eastern India viz. CRRI, Cuttack (Orissa); OUAT, Bhubaneswar (Orissa); CRS, Masodha (UP); RAU, Pusa (Bihar) and RARS, North Lakhimpur (Assam). Pooled analysis of variance reflects existence of genotype x environment interactions and contribution of both linear and nonlinear components to genotype (G) x environment (E) interactions. Through stability parameter analysis it was found that Rayda ~textrmB3 , CR 778-95 and CR 661-236 were suitable for over all environments where as Sabita, OR 1334-16 and OR 1358-RGA-4 were suitable for rich environments. PSR 1209-2-3-2, CR 780-1937, Ambika, OR 877-ST-4-2 and CR 662-2211 were identified for poor environments.

This study was conducted to investigate the varietal differences in leaf senescence during ripening stage and its relation to grain yield of rice. During grain filling period leaf senescence was evaluated by SPAD readings (an indirect indicator of chlorophyll content) for 74 varieties including local, improved domestic, and introduced varieties in the field condition. Leaf senescence was varied greatly among 74 varieties. Jodongji and Dadajo known as local rice varieties had significantly lower SPAD value than the other varieties and became senescent rapidly. However, SPAD value of the flag leaf and 2nd leaf of SNU-SG1 were much higher than the other varieties and leaves of SNU-SG1 also showed a tendency of delayed senescence compared to the other varieties. There were significantly positive correlation between cumulated SPAD value of upper leaf(flag leaf and 2nd leaf) during 35 days after heading and grain yield divided by sunshine hour during 40 days of grain filling and compensated for temperature effect, and cumulated SPAD value of the 4th leaf showed negative correlation with the yield. That is, the delayed senescence of the upper leaves and the rapid senescence of lower leaves were positively associated with grain yield increase.

A new covered barley variety, 'Daeyeonbori' was developed from the cross between Milyangketbori, a stabile for machine harvest, and Olbori by the barley breeding team in the National Yeongnam Agricultural Experiment Station (NYAES) in 1999. An elite line,

벼 자동화 육묘시설에서 파종기별 적정 파종량을 선정하기 위하여 실험한 결과를 요약하면 다음과 같다. 1. 파종기에 따른 묘특성은 상자당 파종량이 증가할수록 초장은 커지는 경향을 보였으나, 묘충실도는 감소하였다. 2. 이앙기별 파종량에 따른 본답 생육 특성은 파종기에 관계없이 파종량이 증가할수록 이앙 초기에는 초장은 커지고 분얼수는 증가하였으나 이앙 40-50일 이후부터는 파종량간에 큰 차이를 나타내지 않았다. 3. 파종량에 따른 수량성은 5월 25일 이앙구에서는 파종량 간에 유의성이 없이 200g 파종구에서 수량이 가장 높았으며, 2모작인 6월 20일 이앙의 경우는 200-250g 파종까지는 유의성이 없었으나, 200-250g 파종구와 300g 파종구에서는 유의성 있는 차이를 보였다.

An efficient low-input system (LIS) for fertiliser use in rice cultivation is necessary to reduce fossil energy use and pollution. Japanese people like Japonica rice, especially cv. Koshihikari. However, it has very low lodging resistance in Japanese weather condition. Our objective was to develop a LIS with the minimum sacrifice of grain yield in rice. Koshihikari was grown using conventional fertilization as a control (CON) with 4 g N m-2 ., 8g P2 O5 m-2 and 8 g K2 O m-2 as a basal fertilizer dressing. It was compared with a low fertilizer treatment (LF) with only 4 g P2 O5 m-2 as a basal dressing in the first year and no basal phosphorus fertilizer in the second year. Chopped rice straw was incorporated into the soil before the cropping season in both years. Fertilizer of 4 g N m-2 was top-dressed at 15 days before heading in CON plots and 30 days before heading in LF plots in both years. Lodging was significantly less in LF than in CON plots, however, no rice straw effect was found in low fertilized condition. Grain yields in LF plots were reduced by 15-16% below those of CON plots. Lower yields in LF plots were associated with a reduced number of spikelets per unit area. However, big spikelet size was acquired in LF by 10 days earlier N top dressing than CON plots. A close relationship was found between spikelet numbers and N content of the plant at heading, and between grain yield or shoot dry weight and N content of the plant at maturity. Regardless of the fertilizer application methods, N use efficiency for the number of spikelets, final total dry matter and grain yield was essentially identical among fertilizer treatments. The reduced growth and yield in the LF plots resulted from low absorption of nitrogen. Conclusively, LIS can drastically reduce chemical fertilizer use and facilitate harvest operations by reducing lodging with some yield reduction..

중부지방에 있어 들깨 파종한계기를 구명하기 위하여 대엽들깨를 시험품종으로 하여 4월 30일부터 7월 20일까지 20일 간격으로 파종을 실시하여 얻은 결과를 요약하면 다음과 같다. 1. 만파할수록 출아는 단축되었으며, 개화기, 성숙기는 늦어졌나 개화 후 성숙기까지의 소요일수는 차이가 미미하였다. 2. 파종기가 늦어짐에 따라 경장, 경태, 주당 분지수 그리고 주경절수는 감소하는 경향이었다. 3. 만파할수록 화방군장은 길었으나 화방군수, 화방군당 삭수는 적어지는 경향이었고, 1,000립중은 무거웠다. 4. 종실수량은 6월 10일까지의 파종에서는 차이가 없었으나, 6월 30일 파종에서는 10% 정도 감수되었으며, 7월 20일 파종에서는 62% 수준으로 감수 폭이 컸다.

제주지역에서 잎들깨 품종의 채종을 위한 적정파종기를 구명하고자 잎들깨 1호와 만백들깨를 5월 15일부터 7월 15일까지 15일 간격으로 5회 파종하여 생육 및 종실수량을 조사한 결과는 다음과 같다. 1. 품종과 파종기간 상호작용은 생육일수에서만 유의하였다. 개화일수만이 품종간 유의한 차이가 있었는데, 잎들깨 1호가 만백들깨보다 약 2일 일찍 개화되었으나 성숙기는 약 1일 늦었다. 2. 파종이 5월 15일에서 7월 15일로 늦어짐에 따라 두 품종의 평균 개화일수는 137일에서 77일로, 생육일수는 179일에서 121일로 짧아졌다. 3. 파종이 5월 15일에서 7월 15일로 늦어짐에 따라 경장은 150cm에서 81cm, 분지수는 17.0개에서 7.3개, 주경절수는 16.9개에서 10.3개로 감소되었다. 4. 주당 화방군수는 5월 15일 파종에서 65.6개이었던 것이 파종이 늦어짐에 따라 점차 줄어들어 7월 15일 파종에서 50.7 개이었다. 화방당 삭수는 32.1~33.4개로 파종기에 따른 유의한 차이가 없었다. 1,000 입중은 5월 15일 파종에서 3.2 g이었던 것이 파종이 늦어짐에 따라 점차 무거워져서 7월 15일 파종에서 3.9 g이었다. 5. ㏊당 종실수량은 5월 15일 파종에서 1,820 kg이었던 것이 만파할수록 감소하여 7월 15일 파종에서 1,338 kg이었는데, 5월 15일과 30일 파종간에는 유의한 수량 차이가 없었다. 본 연구 결과에 의하면 제주지방에서 잎들깨 품종의 채종을 위한 파종적기는 5월 상순-하순으로 보인다.

메밀의 수량 증대방안의 일환으로 내도복성 및 잡초방제 효과에 대하여 초장 및 수량을 비교 분석하여 얻어진 결과는 다음과 같다. 1 식물왜화제인 C.C.C. 및 TIBA의 왜화효과는 있었으나 수량에 있어서는 이들 두처리구 모두 관행구보다 낮았으므로 왜화를 통한 도복경감과 수량증대 효과는 없었다. 2. 적심의 효과는 3엽기, 5엽기, 7엽기 적심에서 초장의 차이는 나타나지 않았으나 적심시기가 늦으면 늦을수록 수량은 현저한 감소를 초래했다. 3. 도복방지를 위한 지지망 설치구에서는 관행 구보다 약간 수량이 증가하였으나(4kg/10a)실제 농가에서는 적용하기 어렵다고 판단되었다. 4. 메밀 파종 후 2일째에 라쏘 유제를 살포한 결과 방제효과는 뛰어 났으나 초장이 잘 신장하지 못하며 수량도 관행구보다 낮았다. 따라서 메밀 재배에는 제초제의 필요성이 없다고 하겠다. 관행구에서의 잡초발생은 주로 강아지풀, 바랭이, 망초, 개망초, 벼룩 나물 종이 우점 하였다. 5 메밀종 각각의 줄기 경도를 측정한 결과 Fagopyrum urophyllum의 경도가 가장 높았다. 따라서, F. urophyllum의 유전자를 재배품종에 도입하는 육종연구가 요망된다.

This experiment was conducted to evaluate the effect on evapotranspiration and yield of soybean according to different soil water conditions, and to find the optimum time and amount for irrigation in soybean cultivation. The difference between potential evapotranspiration (PET) and maximum evapotranspiration (MET) during growing season of soybean planted in lysimeter was higher during reproductive stage than during vegetative one. The maximum crop coefficient was obtained at beginning seed stage of soybean. Soil water coefficient of irrigation treatment was higher than that of non-irrigation treatment during soybean growth stage in field experiment. Grain yield was highest in lysimeter due to its high water use efficiency and evapotranspiration rate.

This study was conducted for 2 years at Chinju region to establish suitable seeding rate and fertilizing levels of nitrogen, phosphorous and potassium in spring-sown Jinyangbori. Heading and maturing were delayed by increasing fertilizers, especially nitrogen. Number of spikes per were secured by much seeding and increased application of nitrogen. One thousand grain weight reduced with increasing fertilization at any seeding rate. Relatively high harvest indices were observed with 12-10-4 at 10kg. 10a-l seeds planted, followed by 6-10-8 at 15 kgㆍ 10a-1 , and 6-10-4kgㆍ 10a-l at 20kg ㆍ 10a-l of N-P-K fertilizing combinations, respectively. There was no distinct differences on yield for various seeding rates in spring-sown barley. When seeding rate increased up to 15kgㆍ10a-1 , the positive effect of fertilizers was recognized as the function of balanced-application. It was possible to recommend 10kgㆍ10a-1 as seeding rate and 6-5-4(N-P-K)kgㆍ10a-1 as fertilizing combination in spring-time seeding considering low input and sustainable agriculture. There was no significant difference of protein content in grain by seeding rate. Increase of nitrogen fertilizer enhanced protein content in grain