• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.2
• /
• pp.118-127
• /
• 1984

In order to find an appropriate model for rice crop-season, the possibility to utilize the geographical conditions instead of meteorological factors was examined on the data from the Local Adaptability Test(LAT) conducted over the country from 1962 to 1980. The mutiple regression model, $Y={\Upsilon}={\ss}{\sum}_{i=1}^n{\beta}^1X^iwas applied on seeding, transplanting, heading and marginal heading date, and multiple regression coefficients(\beta) and multiple correlation coefficients (R) were tested. Two varietal groups, japonica(1962-l971) and indica/japonica(l972-1980) were separately tested. The application of these established models, growth duration in nursery and paddy field, cultural season, and the relation between heading date and yield are reviewed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.28 no.3
• /
• pp.203-214
• /
• 2008

The overwintering crops, barley, wheat, oat and triticale etc, have been received in korea as high-quality roughage for round-baled silage making as livestock feed. Studies were carried out to evaluated the effects of seed blending on growth, yield and feed value between barley and wheat, triticale and oat, respectively. The results are summarized as follows : The barley was declined in the growth and spike's size as affected by sown as mixed seeding with triticale, but not effected with oat. The total fresh yield were increased by grown as mixed seeding with wheat, triticale and oat, but the dry matter yield were not significantly increased because of the low percentage of dry matter and the decrease of barley's growth. The neutral detergent fiber (NDF) and crude protein content were increased by seed blending, but acid detergent fiber (ADF) and digestible dry matter (DDM) content were decreased. The feed value was improved by seed blending of barley and wheat, but not significant at seed blending of triticale and oat. Because of the flourishing tillers, difference of heading date and abundant leaves of oat, the optimum crop for mixed seeding with barley for increment of forage productivity was oat in middle area of korea.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.3
• /
• pp.286-291
• /
• 1997

This experiment was carried out to improve seedling emergence and establishment in paddy rice sown into puddled soil. Rice seed were coated with CaO$_2$, KNO$_3$ and acid sulphate soil. When coated seeds with CaO$_2$, KNO$_3$ and acid sulphate soil were sown into puddled soil, soil redox potential was increased and the period of oxidizing was longer in KNO$_3$ than that of any other soils. pH was higher in control than that of coated seeds with CaO$_2$, KNO$_3$ and acid sulphate soil. It seems that the coated seeds oxidize soil locally, thus prohibit soil reduction. Seedling emergence was improved by seed coating materials. Emergence date was 8 days after seeding(DAS) in CaO$_2$, 14 DAS in acid sulphate soil, 21 DAS in KNO$_3$ coated seed and 20 DAS in uncoated seed, respectively. Emergence rate was highest in CaO$_2$ coated seed(80％) followed by acid sulphate soil coated seed(61％), while control(46％) and KNO$_3$(42％) were very poor. This result would be interpreted as the difference in oxidizing power among coating agents ; CaO$_2$ and acid sulphate soil may oxidize weakly and shortly while KNO$_3$ may oxidize soil strongly and persistantly. Our results suggested that local oxidizing around rice seed sown into puddled soil enhanced seedling emergence and also found a possibility to promote seedling emergence with acid soil.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.1
• /
• pp.89-94
• /
• 1999

This experiment was carried out to determine harvest date and cultivar effects on growth characteristics, forage yield and quality of spring sown oats at the middle mountain(450m) area at the forage experimental field, Namweon Branch, National Livestock Research Institute. The experiment was arranged in a split plot design with three replication. The main plot consisted of the harvest date(9 June, 18 June). The subplots consisted of different maturities of oat cultivars such as Cayuse, Swan, Foothill, Cashel, Martlock and Winjardie. The results obtained are summarized as follows; A period of 50 days was required to be first headed from seeding with early maturity oats(Swan), but that of 77 days was required with late maturity(Foothill). The dry matter content of early maturity(Swan) oats at 9 June and 18 June were 24.01% and 35.69%, but that of late maturity cultivars(Foothill) were 14.02% and 22.84%. The fresh yield of late maturity(Foothill) oats at 9 June and 18 June were 62,666kg and 59,666kg, but that of early maturity(Cashel) were 54,222kg and 45,493kg(P<0.05). The dry yield of early maturity (Cashel) oats at 9 June was 10,169kg, but that of early maturity (Martlock) was 6,272kg. But no significant difference was found among cultivars at June 18. Crude protein content of oats were decreased from 14.0% to 11.1% as the growing stage progressed, ADF, NDF and CF contents were increased. And in vitro dry matter digestibility was decreased as the harvest date delayed. The present experiment indicated that spring sown oats(Foothill) can be successfully produced as fresh forage by seeding in middle March and harvesting in 10 and 20 June at the middle mountain (450m) area.

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.511-518
• /
• 2016

The subject of this experiment is to supply basic data to inhibit non-productive tillers which are uneconomical for mechanical harvesting and to evaluate optimum planting density and sowing date in central district. Total number of tillers and effective first and second of tillers according to different planting density was higher in 80 ㎝ ridge than 60 ㎝ ridge in proso millet. The wider between plant distance on the ridge, the more increased total number of tillers and effective first and second of tillers. The highest effective tillers (91.7 %) in the first tillers was obtained from the second sowing date (23 May) among different sowing date and next is in the order of 3^rd(13 June, 89.8%) > 1^st(2 May, 85.6%) > 4^th(4 July, 85.2%). The percentage of effective tillers in the second tillers was decreased in the order of 2 May (53.7%), 23 May (40.7%), 13 June (22.2%), 4 July (0%) as the sowing date was delayed. There was no significant difference in days to heading and days to ripening according to different planting density. Although culm length was increased as planting density was increased, whereas number of tillers, stem diameter, ear length, grains per ear and 1000 grain weight was decreased. In the growth and yield characteristics of proso millet according to different sowing date, days to heading and days to ripening, culm length, stem diameter, ear length, grains per ear and yield per 10a were decreased. After the sowing date of 13 June, the reduction of growth and yield characteristics were higher because of excess-moisture injury.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.14
• /
• pp.53-64
• /
• 1973

The studies reported herein were conducted to investigate the effect of thermal conditions in double-cropping of rice. The accumulated daily mean and minimum air temperatures, for the period of the last 30 years, were examined at the 10 different meteorogical stations which are located in the southern part of Korea. The results obtained could be summarized as follows: 1. The first cropping. a. It seemed to be free from any frost-damage of rice at the seeding stage at Yeosu, Pusan and Cheju. However, it was found that there were some dangers of frost damage for about 30 to 40 day at Iri, Chonju and Kwangju, for 18 to 28 days at Daeku and Ulsan, and for 4 to 14 days at Mokpo and Pohang, respectively. b. The early critical transplanting date seemed to be from middle to late-April in the first cropping. As compared with the ordinary lowland seedlings, the semi-protected and upland ones could be planted 5 and 10 days earlier, respectively. c. The early critical heading date was about late-June and there were some low-temperature damages for 8 to 25 days at young-ear formation stage of rice plant, depending upon location. d. The early critical ripening date (the early critical transplanting date of the 2nd cropping) was from late-July to early-August. It took about 32 to 39 days in ripening. There was a tendency of SS${\fallingdotseq}$SL$15^{\circ}C$ (${\theta}$15) and the minimum of $10^{\circ}C$ (${\theta}$10), the ten locations could be devided into two ripening groups of ${\theta}$15>${\theta}$10 and ${\theta}$15<${\theta}$10. c. The late critical ripening date was around October 9 at Iri, Chonju, Kwangju and Daeku and around October 28 at Mokpo, Yeosu, Pusan and eheju. Three to four days were more required for a complete ripening of rice, as compared with the above dates. d. There was an overlap of about 12 to 42 days between the first and second cropping when early-maturing varieties requiring an accumulated mean air temperature of $1, 550^{\circ}C$, from transplanting to heading, were grown. Therefore, some varieties which could head with an accumulated daily mean air temperature of 1, 000 to $1, 200^{\circ}C$, should be either developed or some new cultural technology be established in order to have a successful double cropping in rice.

• Korean Journal of Weed Science
• /
• v.16 no.2
• /
• pp.88-99
• /
• 1996

In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.3
• /
• pp.184-187
• /
• 2004

In case of a semi-forcing culture for vegetable perilla, the following research results on the effect of black polyethylene mulching, the optimum sowing season, and the seedling stand improvement method were drawn. Soil temperature was higher and the emergence was faster in a black polyethylene mulching culture than in a non-mulching culture. However, the mature was late, the main stem were larger, and the seed yield, as well as the leaf yield, was greater in a mulching culture than in a non-mulching culture. Considering growth and chilling injury, the stable sowing season of vegetable perilla was judged to be the early in January. The covering materials for improvement of the seedling stand can be a non-woven fabric and hyaline polyethylene. However, the non-woven fabric seemed to be quite suitable in view of the stability and convenience of control after the emergence of perilla.

• Asian Journal of Turfgrass Science
• /
• v.11 no.3
• /
• pp.161-166
• /
• 1997

This study was performed to develope the method of wildgrass to process as hydroseeding material which is a most popular revegetation method for Slope areas through the control of soil eroison and stability by seeding grasses. The wildgrass material for the processing were harvested at Suwon, Kyungki-do and Wonju, Kangwon-do in 1994. The investigations were established in laboratory for pot and field experiment with seven treatments by harvesting date and place in 1995. Results indicated that wildgrass harvested field in open space or road side was able to be used as hydroseeding material by proper processing. It was possible to substitute wildgrass seed to conrrnercial turfgrass seed, and plant tissue to mulching fiber by drying and crushing process. Germination of wildgrass seed was relatively slower than control (20g /$m^2$ turfgrass seed) in early stage of 20 days, but surface revegetation rate was higher in 50 days at wildgrass plot than control applied by normal hydroseeding method. Mixture of 5g /$m^2$ of cool season turfgrass seed to wildgrass material increased the rate of early stage of germination and surface revegetation. The application of wildgrass as hydroseeding material showed more naturalistic scenery than rutine hydroseeding with imported cool season turfgrass seed. Key words: Rydroseeding, Turfgrass, Wildgrass, Revegetation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.4
• /
• pp.362-365
• /
• 1984

Application of phosphate and silicate at the seed bed stage of rice seedlings was investigated to improve nutritional condition and rooting capability at low temperature. The amounts of applied phosphate were 15kg/10a with or without 200 kg/10a of silicate, and 30 kg/10a without silicate. Seeding dates were March 31, April 9 and April 19. The dry weight of the seedlings seeded earlier date under low temperature was lower than that of the seedlings seeded later dates. The application of phosphate and silicate increased the dry weight of newly developed roots after trasplanting, and increased the number of tillers. Therefore, heavy application of phosphate and silicate is recommendable to improve the predisposition of the rice seedlings grown under the low temperature condition for early transplanting.