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.

본 연구는 유색미 품종들의 적정 재배시기와 지역에 따른 색소발현 및 항산화 활성 변이를 분석하여 고품질의 유색미를 생산할 수 있는 적정 재배관리기술의 기초자료를 얻고자 수행하였고 그 결과는 다음과 같다. 1. 밀양, 봉화, 상주, 의성 4지역에서 이앙시기를 5월 20일, 6월 5일, 6월 20일 3시기에 걸쳐서 흑미 3품종과 적미 2품종을 재배한 결과 출수 후 30일간의 평균기온 19.0℃ 이상에서 평균기온이 1℃ 증가할 때마다 흑미의 안토시아닌 함량은 약 9.9%, 적미의 총폴리페놀 함량은 약 9%씩 감소하였다. 2. 유색미의 기능성물질 함량을 증대시키기 위한 출수 후 30일간 적정등숙온도는 흑미의 경우 조생종은 22~23℃, 중만생종은 21~22℃의 범위였으며, 적미도 21~22℃ 범위였다. 3. 전국 지역별 30년간의 기상자료를 토대로 적정출수기를 추정한 결과 제천지역은 조생종이 8월 11일에서 8월 17일, 중만생종은 8월 25일경이며 보은지역은 조생종이 8월 15일에서 8월 19일, 중만생종은 8월 20일에서 8월 27일에 해당되었다. 영주지역은 조생종이 8월 15일에서 8월 21일, 중만생종은 8월 24일 경이었고, 충주지역은 조생종이 8월 17일에서 8월 23일, 중만생종은 8월 22일에서 8월 29일에 해당되었다. 대구지역은 조생종이 8월 27일에서 9월 2일, 중만생종은 9월 3일에서 9월 6일경으로 주요 재배적지는 제천, 보은, 문경, 영주 등이었다. 4. 적정파종기 추정결과 제천지역은 조생종이 5월 18일에서 5월 26일, 중만생종이 4월 11일 경이었으며, 보은지역은 조생종이 5월 23일에서 5월 28일, 중만생종이 4월 9일에서 4월 26일, 문경지역은 조생종이 5월 24일에서 6월 1일, 중만생종이 4월 21일에서 5월 4일, 영주지역은 조생종이 5월 22일에서 5월 30일, 중만생종이 4월 13일에서 4월 27일, 충주지역은 조생종이 5월 31일에서 6월 7일, 중만생종은 5월 4일에서 5월 14일 경으로 추정되었다.

Barnyard grasses are dominant weed that are not eliminated easily in the direct water seeding cultivation. So, deep water treatment can reduce their growth at the early growing stage of submerged paddy. This study was carried out to investigate the reducing growth of the barnyard grasses through flooding at seedling stages of rice plant in the green house. Under the normal condition, the plant height of rice variety, Samgwangbyeo, and 3 species of barnyard grass, E. caudata, E. pratocola and E. utilis were not showed the difference up to 10 days after seeding while the plant height of 3 barnyard grass species, especially E. utilis, was more elongated than the rice at 25 days after seeding. Plant height of the 3 barnyard grasses were not elongated largely during 3, 5 and 7 days of flooding treatment at 10 days after seeding. Interestingly, the rice seedlings was grown over 20 cm, and the flooding tolerance of rice seedling was higher than the 3 barnyard grass varieties. However, after flooding treatment for 3, 5 and 7 days, the elongation of plant height of 3 barnyard grasses, especially E. utilis was more speedy compared to rice seedlings as 6 to 9 days passes. And the protein spots from barnyard grasses were also reduced and eliminated more than the spots of rice seedling after flooding treatment.

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.

Light is a energy source for photosynthesis og green plant and sources for photoperiodsm and photomorphogenesis. Plants have showed a variety of reactions corresponding to the surrounding environment to survive, and have introduced environmental signal into growth development. Rice yield has reduced by increasing localized heavy rain that leads duration of solar intensity to decrease 10-16% during cultivation period. It is necessary to improve adaptive technology and observe change of rice yield and growth by decrease of solar intensity for safe culture of rice. For these reasos, we carried out shade culture experiment and compared to rice growth and yield for two rice varity(Dasanbyeo, Chuchengbyeo) in 2008, and we also performed shade culture experiment at two growth stage(panicle formation stage, booting stage) in order to research rice growth and yield by decease of solar intensity on 2009. We carried out shade treatment to make different solar intensity under three different conditions; control, 30-40% block, 70-80% block using shade net. As a result, experiment result showed that plant height and SPAD value were more inceased and tiller number was more deceased under shade treatment than control. Shade treatment decreased rice yield by reducing panicles number per m2 spikelet number per panicle, and percent ripened grain of yield component. The results of protein analysis showed difference between control and treatment.

Direct seeding is increasingly being practiced by rice farmers under both rainfed and irrigated conditions. The trend is the outcome of a scarcity of labour required for transplanting, simplicity and additional benefits associated with direct seeding. Flooding slows seed germination, imposes fatalities and delays seedling establishment in direct-seeded rice. This study describes responses of contrasting rice genotypes subjected to flooding or low oxygen stress during germination and discusses of tolernace shown by certain cultivars. In expt, two tolerant('Khao Hlan On', 'Khaiyan') and two intolerant('IR 42', 'IR 64') genotypes were used for growth and survival measurements. To compare effects of priming, pre-germination and germination on anaerobic tolerant and intolerant lines. Length of the longest shoot was measured in seedlings grown under either a control or in flooded soil, and plant survival was calculated based on the number of seedlings that emerged from floodwater. All measurements were 21 d after sowing. Tolerant and intolerant genotypes had the same seeding survival under normal soil conditions. But survival of intolerant genotypes were lower than tolerant genotypes. Growth of tolerant genotypes were faster than intolerant genotypes. Among the treatment, treatment 3 was greater. Because treatment 3 emerged first from water. Among the after days 1, 3, 5, survival was highest in after day 1. The other side, To late seeding over time, survival decreased.