• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.1
• /
• pp.57-64
• /
• 1991

This experiment was conducted to elucidate the effect of plant growth regulators (PGR) on the root -mat formation of infant seedling (8- to 10-day-old seedling) of rice in machine transplanting. The rice seeds of Odaebyeo were socked in water with different concentrations of PGRs for 48 hours at room temperature. Seeding rate was 220 g per seed tray (30x60x3cm). Metalaxyl (25% wettable powder) was used for a fungicide. Generally, the metalaxyl-treated seeds markedly promoted the root growth of the rice seedling, while tetracy-cle, pachlobutrazol and NTN -821 reduced the seedling height and root length, and thickened the shoot diameter at higher concentation levels. Tetracycle decreased root length of the rice seedlings but increased root number per seedling, and root-mat formation was poor. Whereas, metalaxyl concentrations of 200 and 1,000 ppm markedly increased root length and number of root hairs without decreasing root number, thus root-mat formation was excellent. The optimum concentration of metalaxyl seed treatment to increase the root-mat formation of infant seedling of rice was about 200 ppm. Metalaxyl seed treatment could be advanced one to two days of the duration of root-mat formation compared with control.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1994.06a
• /
• pp.110-111
• /
• 1994

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.1
• /
• pp.86-92
• /
• 1992

Green buckwheat seedlings have been used as a pollution free vegetable and medicinal crop for a long time. Some of the reasons are the rapid growth rate, the high protein and rutincontent, and a more favorable ratio of leaf to stem than mature plants. Off-crop season cultivation techniques were developed for growing the young and green buckwheat vegetable of higher quality and yield, and for its increased value-added income. The effects of planting season, seeding rate, seed bed soil fertility and type, and seedling growth period on yield and rutin content were determined for vegetable and medicinal use. The young vegetable yields. in the off season culture ranged from 2.62t/ha to 22.7t /ha. The highest vegetable yield was 22.7t /ha for 25 days old seedlings grown in the polyethylene film tunnel from March 30 to April 25, 1991 where seedling rate was 360kg /ha. Buckwheat vegetable quality and income were dependent upon planting season, seeding rate, growing duration and temperature, and facilities of raising seedlings. Protein content of buck-wheat seedlings was from 21.5% to 17.2%. Rutin content of the vegetable was 53.9～31.7mg /100g for the whole plant in average. The protein and rutin content was significantly varied due to the different environmental conditions including fertility and type of seed bed soil, growing duration, temperature of the green house, and polyethylene film house and tunnel.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.4
• /
• pp.441-448
• /
• 2012

This study was carried out to evaluate the productivity of rice cultivation in extremely late season in Korea and to confirm the effects of pot-raising seedling culture in this case by assessing the growth and yield performance of rice cultivars that are well adapted to late culture. Suitable cultivars for extremely late culture should not have premature heading habit when transplanted around late July and also secure appropriate growth duration before heading. Geumobyeo 1 and Manjongbyeo showed small decrease in the emerged leaves in transplanting in late July or early August and heading occurred at the same time relatively without premature heading. At transplanting from late July to early August in extremely late rice cultivation, ripening was relatively good until transplanting on August 5. At transplanting on July 30, accumulated temperature from heading to the first frost was $853^{\circ}C$ and ripening was good enough. However, heading was delayed by low temperature at transplanting on August 10 and ripening was very poor due to low accumulated temperature of below $800^{\circ}C$, causing drastic decrease of rice yield. The rice yield increased in transplanting with pot seedling, especially the effects of pot seedling was higher in Geumobyeo 1, but panicle number was not enough to secure rice yield owing to short growth duration. In order to cultivate rice in extremely late season, we should select adaptive rice cultivars that have suitable growth duration and excellent ripening in low temperature. Here, pot-seedling did a great role to secure early growth and bigger growth amounts.

• Journal of Korean Society of Forest Science
• /
• v.110 no.3
• /
• pp.406-418
• /
• 2021

This study was conducted to evaluate optimal storage techniques for bare root plants and container seedlings of Quercus variabilis and Zelkova serrata in order to maintain high quality of seedlings until planting. Refrigerated storage treatments were given at two temperatures (-2℃ [freezing] and 2℃ [cooling]) for nine different durations (0, 15, 30, 60, 120, 180, 240, 300, and 360 days after storage). We analyzed total nonstructural carbohydrate (TNC) content and measured shoot moisture content (SMC) during the storage stage and survival rate (SR) and dry weight during the planting stage of seedlings. The TNC content and SMC of the seedlings of the two species decreased with an increase in storage duration. The TNC content of seedlings rapidly decreased after 180~240 days of storage. The TNC reduction rate in the freezing treatment was lower than that in the cooling treatment. Also, with an increase in the storage duration of the two species, the SMC reduction rate in the cooling treatment increased in comparison with that in the freezing treatment. In both the species, the SR after planting decreased rapidly after 60 days of cooling storage and 180 days of freezing storage, respectively. The SR after planting was less than 60% when the TNC content for both the species dropped below 20 mg g^-1. In addition, the SR was lower than 80% when SMC measured before storage decreased by approximately 30% and 20% for Q. variabilis and Z. serrata, respectively. Our results suggest that cooling (1~2℃) storage is recommended for a short-term period (2 months or less), whereas freezing (-2~-4℃) storage is suitable for longer periods (2~6 months). These optimal storage techniques, allied with seedling harvesting and handling systems, will improve the quality of seedling production in nursery stages and increase seedling growth performances in plantations.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.42-48
• /
• 1997

Ten days old rice seedlings were treated with NaCl and the contents of endogenous hormones such as GA$_3$, ABA, IAA and zeatin were measured by ELISA. Water content and seedling growth were decreased as the salt concentration was increased. GA$_3$ increased up to 24 hours after NaCl treatment and decreased thereafter. ABA was raised by four times in 48 hours after NaCl treatment. IAA and zeatin decreased as the NaCl concentration and duration of treatment increased. GA$_3$ and ABA showed positive and negative correlation with the water content in the plant tissue, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.10
• /
• pp.73-77
• /
• 1971

The experiment was carried out to investigate post-irradiation storage effect which was related to temperature(i.e. at 2$^{\circ}C$, 17$^{\circ}C$ and 4$0^{\circ}C$) on wheat seeds; Weibull's Svenno, treated with gamma-ray and fast neutron. Results obtained showed that the seedling height in both radiation sources was decreased with prolongation of storage period, especially when the seeds were treated with high dosage and stored at high temperature(4$0^{\circ}C$). The results of this trial, however, showed that storage effect was influenced by irradiation dose, temperature and storage time.

• Korean Journal of Medicinal Crop Science
• /
• v.6 no.2
• /
• pp.160-164
• /
• 1998

Angelica gigas has been a major medicinal crop in Korea for a long time. This study was to determine optimum seeding time and bolting response by shifting seeding time between November 10, 1993, and August 10, 1994 using promising line, Suwon 2. Days to emergence were similar among seeding times from April 10 to August 10 in Suwon. Seedling duration was shortened 92 days when seeded on July 10 compared with the conventional seeding time of April 10. Productivity of seedling ranging from 0.31 to 0.70cm in diameter was highest of 730 plants per $m^2$ in July 10 seeding. When seeded in July 10, bolting rate was 2.4 percent as compared with 2.6 percent in conventional seeding (April 10). The optimum seeding time was July 10. Seedling quality, survival rate after planting in field, and root yield were greatly influenced by seeding time.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.426-435
• /
• 2020

To determine the damages to waxy corn caused by low temperature weather, we investigated the relationship between the temperature and duration of low temperature treatment and the changes in growth characteristics during the recovery period after the treatments in different growth periods. Growth inhibition started in the low temperature group treated at temperatures below 5℃ for three days. The inhibition ratio (IR) was more than 22% or more in all sample groups. As the treatment duration increased and the Temperature decreased, the growth was more greatly inhibited than that in the control. The IR was the highest at 27% or more in the 2nd leaf stage group treated at below 5℃ for 5 days. The IR was in the order of 2nd leaf stage > 1st leaf stage > coleoptile. The IR during recovery was the highest in the 2nd leaf stage group treated at -3℃ degree for 7 days, nd the values were 82% and 98% for NDVI and Fv/Fm, respectively. Especially, all groups treated at -3℃ showed either no changes or decreases in the growth characteristics. As a result, growth inhibition increased as the temperature decreased, and as the duration of the low temperature increased. The degree of damage was in the order of 2nd leaf stage > 1st leaf stage > coleoptile. All early seedlings stopped growing and withered when exposed to temperatures at or below -3℃ for 3 days or more.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.10 no.1
• /
• pp.77-90
• /
• 2008

This study was conducted to investigate the influence of chilling temperature and duration at different seeding stages on yield, fruit characteristics and growth of cucumber in a greenhouse. When 20-day-old cucumber were exposed to 0 and 3℃ for 10 hours, 25 and 30% reduction in the main stem elongation rate and 34 and 37% reduction in total leaf area per plant were observed. The reduction in stem elongation and total leaf area was apparently associated with the increases in chilling duration. Exposure of seedlings to 6℃ failed to causes any significant differences in growth as compared to the unchilled plants. Repeated exposure of seedlings to 3℃ chilling for 10 hours per day increased the chilling injury significantly. The seedlings exposed to low temperature for 3 consecutive days exhibited severe injury as compared to the seedlings exposed to chilling treatment only once or twice. Fruit elongation rate was inhibited by approximately 10%, such as 0.59~2.26cm/day, with chilling of 15 hours at 0℃ as compare to 0.61~2.60cm/day in the non-chilled plants. Chilling treatment at 0~3℃ for 10 hours reduced the percentage of marketable fruits by 25~26%. while it increased the percentage of severely bent fruits significantly. Total fruits yield was reduced by 15~25% in cucumber plants when the chilling treatment was given to 20-day-old seedlings and by 22~37% in 30-day-old seedlings. This shows that, Larger seedlings were more sensitive to chilling. Total yield was also influenced by the duration of chilling. Definitely, at 0℃, 5-hour chilling treatment caused 18% of reduction, 10-hour caused 30%, and 15-hour caused 36%, respectively.