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.

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.