This experiment was conducted to clarify the information in this field for increasing rice production by rice breeding in ceylon.
1) Seventy-six local rice varieties collected from dry zone in Ceylon and three recommended rice varieties (H4, H8 and IR8) were used.
2) According to Matsuo (1952), most of them were classified into C type and the others were classified into A type.
3) These local varieties have a wide genetical variations in most of the measured characters. The characters of small grain type called Samba rice by Ceylonese have shown similar variation compared with ordinary varities except the shape of grain.
4) In general high correlationships were observed among most of the measured characters, however, degree of shattering, number of degenerated secondary rachis branches and number of panicles were found to be much less correlated with the other characters.

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The experiment was carried out in 1971 in Japan with container (53cm×35cm) in glasshouse and outdoors using two indica varieties, IR8 and Tadukan, two japonica varieties, Nihonbare and Hoyoku and Blue Rose 41. Transpiration was measured by water balance method. Transpiration ratio (T/Em, Em : pan evaporation from free water surface) was used for discussion in order to eliminate the weather conditions. The results obtained may be summarized as follows:
1.The single peak of transpiration per day was observed at the first part of August during the highest temperature period (Fig.1) . Transpiration ratio increased in proportion to leaf area index (LAI) below LAI 5 and then its increase trend was almost unchanged except for Tadukan (Fig.2-A) . The peak of transpiration ratio was observed at the former or latter half of ripening period (Fig.1) . However transpiration ratio per unit leaf area from plant cover decreased reciprocally with an increase of LAI except for Tadukan (Fig.2-B-1-3) .
2.Transpiration per unit leaf area in indica rice and in natural temperature plot (outdoors) tended to increase at the same levels of LAI and air temperature as compared with those of japonica rice and high temperature plot (glasshouse) respectively (Fig.2-C-1-3) . The highest transpiration activity of Tadukan were due to the highest plant height, small effect of mutual shading and increase of rate in transpiration from leaf sheath and panicle.
3.Transpiration amount during daytime occupied about 85% of total daily transpiration. Rate of transpiration were 40-60% from leaf blade, 30-35% from leaf sheath and 15-25% from panicle at the latter stage of growth under individual plant condition (Table2) and rate of panicle surface area to green leaf area was 11-36% at the full heading time. This suggests that rate of transpiration from panicle increases during ripening period particularly in Tadukan.
4.Daily transpiration per hill were closely correlated with weather conditions and pan evaporation particularly with insolation amount and saturation deficit (Table1) . It can be said that transpiration was affected by LAI and weather conditions before green cover formation and was dominated mainly by weather conditions after green cover formation.

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The experiment was carried out in 1971 in Japan with container under the identical conditions and samples as the previous report. For calculation of water requirement (transpiration coefficient), weight of roots was excluded. The results obtained may be summarized as follows:
1.The peak of increase in dry matter production per day was obtained during booting period with similar trend to transpiration (Fig. 1) . Net assimilation rate (NAR) showed the peak value during former half of tillering period and then decreased gradually with similar trend to transpiration rate.
2.In general water requirement increased gradually after trnsplanting and its peak value was obtained during latter half of ripening period (Fig.1) . However minimum value was exceptionally obtained during booting period in high temperature plots (glasshouse) of japonica rice.
Distinct positive correlations were found between transpiration and dry matter production per day and also between transpiration rate and NAR in various stages of growth (Fig. 2-A-1·2, -B-1) . Hyperbolic curve was obtained between water requirement and NAR and dry matter production (Fig. 2-A-3, -B-2) . These relations signify that plants utilize water more efficiently when dry matter production is most active and therefore water requirement decrease. Indica rice utilized water less efficiently for dry matter production as compared with japonica rice because of the over transpiration (Figs.2 and 3) .
3.Higher water requirement was observed in natural temperature plots (outdoos) as comppared with high temperature plots (Fig.1 and table 1) . This was due to the more transpiration and less dry matter production of the former plots. Positive correlation was not always distinct between growth duration and water requirement.
4.Total dry matter production and yield in high temperature plots were 40-50% and 40-100% higher than those of natural temperature plots respectively (Table 1) . The order of yield was as follows: —Tadukan>B. Rose 41>Nihonbare>IR 8≅Hoyoku. It may be said that some indica rices can show a high productivity, because they reveal the high NAR and transpiration activity when they are planted in the containers with some treatments for lodging prevention.

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Using the paper chromatography and Avena straight growth test method, the relation between seed dormancy and growth substances in seeds of Hadsaduri and other 4 varieties was investigated, in order to make clear the action of growth substances on seed dormancy in rice.
1. There was recognized the clear relation between seed dormancy and growth inhibitors in seeds, that is, the quantities of growth inhibitors were detected in rich amount in the seeds which was ascertained as highly dormant period, and moreover they were gradually decreased in proportion to advancement of seed age. Then, the dormancy of seeds was broken when inhibitors disappeared mostly in seeds.
2. Growth substances of acidic fraction in dormant husked-seeds extracts were composed of two growth inhibitors and one growth promotor, but those in dormant hull contained only two inhibitors.
3. Growth inhibitors on chromatograms were found in Rf 0.7-0.8 and 0.9-1.0 zones, the former was estimated as abscisic acid according to Rf value on the chromatograms and latter was thought as indolic compound reacted to Ehrlich's reagent.
4. Little growth inhibitors were recognized in seeds when seed germination could perfectly occur, and such tendency was not almost differed with the whole varieties used on histograms of growth substances.

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Using 4 strains of barnyard grass seeds, the effects of 3 treatments, namely washing the seeds before sowing, the alternating temperature after sowing and the combination of the both treatments, on the breaking of seed dormancy were investigated. The changes of growth substances that could be simultaneously occurred in seeds by treatments were also examined using Avena straight growth test. The results obtained were summarized as follows.
1. Each treatment of washing the seeds and the alternating temperature accelerated the germination of seeds on deep dormancy and broke the dormancy of seeds on light dormancy, and seed dormancy was always perfectly broken out by combining of the both treatments.
2. Growth substances were eluted in water from seeds by immersing the seeds in water. Judging from the results of Avena straight growth test of the eluate, it was confirmed that growth substances in the eluate consist of not only growth inhibitors but also growth promotors.
3. It was confirmed that growth substances were concerned in the phenomenon of breaking of seed dormancy. It was estimated that breaking of dormancy of seeds could be occurred according as the decrease or inactivation of growth inhibitors and the increase or activation of growth promotors in seeds.

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1) Tomé-Açú, in the northern region of Brazil, is well known for the production of black or white pepper next to the Southeast Asia, where appeared virus disease of the pepper (Piper nigrumL.) in 1969, for the first time. Presently it was ilucidated that the disease was caused by CMV and found to infect by transmitting inoculation test using Aphis gossypii.
2) In the actual pepper farm cultivated in Tomé-Açú, Aphis gossypii is not found generally, but other aphides are common. In the above transmitting inoculation test using the commonest aphis in the pepper farm, the infection was shown, in the only case, by the method using Nicandra physaloides as an intermediate host.
3) The aphis has been identified “Aphis spiraecola” and it could be considered the virus disease, as one case, is to be disseminated by A. spiraecola in the pepper farm actually.

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1) It was proved through the actual curve recorded by the self-recording thermometer and hygrometer in Kotaboemi, Lanpung in Sumatora, Indonesia that the humidity in percentage is low in the day time and high in the night.
2) An exclusive study has been carried out on a cover-type moveable drying device that can be made by common local farmers in Indonesia within their abillity and funds provided.
3) The drying device to be developed is a set of the finishing dryer consisted of two drying frames, an agricultural diesel engine, a blower and a burner, which are locally available from the viewpoint of cost saving and improving the quality of agricultural products.

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