• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.3
• /
• pp.184-188
• /
• 2001

This study was conducted to find out the basic informations related to the rice cultivation using the infant seedlings. Infant seedlings with different nursery Periods were compared for the growth and grain yield of rice at the National Crop Experiment Station in 1997. The highest sound seedling ratio of 93.9% was observed in 8-day old seedling, followed by 88.9% of 12-day, 82.0% of 16-day, and 80.8% of 20-day, The endosperm remained 52.5% in the 8-day old seedling at transplanting and decreasingly with increasing nursery period. Missing hills at transplanting were more in 16-day and 20-day old seedling than in 8-day and 12-day old seedlings, 5.1-5.2% in 8-day and 12-day growing seedling, 6.7% in 16-day and 7.8% in 20-day old seedling. Rooting ability was observed highest in 8-day, followed by 12-day, 16-day and 20-day old seedling. The milled rice was lower by 5-16% in 12-day, 16-day and 20-day old seedling than in 8-day old seedling of 6.18 t/ha. It was found that the 8-day and 12-day old seedling provided more advantage for sound seedling ratio, endosperm remaining, missing hill during transplanting, rooting ability and grain yields than 16-day and 20-day old seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.3
• /
• pp.257-265
• /
• 2015

This experiment was carried out to determine the optimum planting density for rice pot seedling cultivation in wheat-rice double cropping system in Honam plain area. A mid-late maturing rice variety 'Chinnong' was raised in pot seedling tray and conventional tray for 30 days, and then transplanted on June 25 in 2012 and 2013. Four different planting densities (15.2, 18.9, 21.6, and 25.3 hills per $m^2$) in pot seedlings were applied as treatment. Conventional tray seedling was implicated as control at a single planting density of 27.8 hills per $m^2$. In this experiment, the number of effective tillers was increased as planting density increasing, but stem diameter was decreased. Pot seedling showed higher stem diameter and effective tillers than the control. Heading dates of pot seedling plots were not significantly different between the planting densities but 2 days faster than the control. Culm length, number of panicles, panicle length, and ripening grain ratio were higher in pot seedling compared to the control, but 1000-grain weight showed no significant difference. Milled rice yields in pot seedlings ranged from 5.19 to $5.43\;t\;ha^{-1}$, and the highest yield was observed in 21.6 hills per $m^2$. Head rice ratios in pot seedlings and the controls were not significantly different. Above results on planting density of rice pot seedling cultivation would be applicable to wheat-rice double cropping and also to late transplanting cultivation of rice single cropping.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.6
• /
• pp.384-386
• /
• 2005

This research was conducted to determine the contents of sugar and starch between rice cultivar, ASD1 being with high seedling establishment under direct seeding cultivation and IR72 being with poor seedling establishment. The ASD1 rice cultivar was higher in sugar and starch contents than those of IR72 during germination. This result was proven to the previous research out­put with high seedling establishment in direct seeding condition as well.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.6
• /
• pp.534-540
• /
• 1992

Climatic condition and seeding depth affect the seedling stand and early growth in the direct-seeded rice cultivation on dry soil. This experiment was conducted to elucidate the effects of the day /night temperatures and the seeding depths on the seedling emergence and mesocotyl elongation of rice seed. Three combinations of the day/night temperatures(25/2$0^{\circ}C$ 20/15$^{\circ}C$ and 20/1$0^{\circ}C$) were employed with seeding depths 1, 3, 5 and 7cm at the Phytotron of the Crop Experiment Station in 1991. It appeared that seedling emergence ratio increased and days to seedling emergence decreased in the high temperature (25/2$0^{\circ}C$) and the deep seeding depth (5 and 7cm) condition. The seedling emergence ratio did not. show the, difference up . to the seeding depths of 3cm and below, but the ratio decreased from the seeding depths of 5cm and above. Plant height and leaf number were almost the same up to the depths of 3cm at 30 days after seeding, but those of the seeding depths of 5cm and 7cm were remarkably reduced in all temperature combinations. Mesocotyl and lower internode elongation were seen in the high temperature(25/2$0^{\circ}C$) with the seeding depths of 5cm and 7cm. In the seeding depth of 6cm, of the tested varieties, Tamjinbyeo and Odaebyeo showed the highest emergence ratio. Generally, leaves of all tested varieties appeared approximately in the soil depth of 3cm, so the reasonable seeding depth will be around 3cm in the direct-seeded cultivation on dry soil.

• Korean Journal of Weed Science
• /
• v.13 no.2
• /
• pp.114-121
• /
• 1993

Differences in need occurrence and competition were investigated among five types of rice(Oryza sativa L.) cultivation. Dry weights of weeds in between transplanting and/or seeding and heading date showed in the decreasing order of dry direct-seeded, flood direct-seeded, machine transplanting with 10-day-old seedling, machine transplanting with 30-day-old seedling, and conventional hand transplanting. A similar trend was obtained with application of weedy followed by weed-free. Weed-free periods allowed to decrease by 20% dry weight of rice were 3 weeks after transplanting(WAT) in transplanting cultivations, 5 weeks after seeding(WAS) in wet direct-seeded rice, and 7-8 WAS in dry direct-seeded rice. On the other hand, weedy periods as determined by the same criterion were 9 WAT in conventional hand transplanting and machine transplanting with 30-day-old seedling, 7 WAT in machine transplanting with 10-day-old seedling, 8 WAS in dry direct-seeded rice, and 6 WAS in flood direct-seeded rice.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.327-327
• /
• 2017

The effect of different seedling ages and transplanting times on the growth and yield of Indica ${\times}$ Japonica rice for noodle processing was evaluated to develop a high yielding cultivation technology for increasing the competition against the imported foreign rice. Four seedling ages (10-, 20-, 30- and 33-day old) of two Indica ${\times}$ Japonica rice cultivars (cvs. Saemimyeon and Palbangmi) and three transplanting dates (May 20, May 30 and June 9) were used in the study. Our results showed that the growth and rice yield of the two cultivars were significantly affected by the different seedling ages and transplanting times. Dry matter production at the panicle heading of the two rice cultivars were generally higher in the 30-day old seedling than the other seedling age treatments and then gradually decreased as the transplanting time was delayed from May 20 to June 9. Similar high panicle number per square meter were recorded at the 30-day old seedling between May 20-May 30 transplanting times. In contrast, other yield parameters that includes spikelet number per panicle, 1,000-brown rice weight, and ripened grain ratio (except for the June 9 transplanting time of Palbangmi) were not significantly affected. The milled rice yield of Saemimyeon was higher than that of the Palbangmi regardless of seedling ages and it was also the highest at the 30-day old seedling with four seedling ages. The milled rice yield of Saemimyeon was only slightly decreased as the transplanting time was delayed from the May 20 to June 9 but Palbangmi had a significantly lower milled rice yield at June 9 transplanting due to the low ripened grain ratio. The result indicates that the most suitable seedling age for the cultivars tested was at 30-day old seedling for noodle processing rice and recommended transplanting times were between May 20 and May 30 for the high rice yield in the Yeongnam plain area.

• Journal of Ginseng Culture
• /
• v.6
• /
• pp.51-79
• /
• 2024

In the 1970s and 1980s, during the nascent phase of ginseng disease research, efforts concentrated on isolating and identifying pathogens. Subsequently, their physiological ecology and pathogenesis characteristics were scrutinized. This led to the establishment of a comprehensive control approach for safeguarding major aerial part diseases like Alternaria blight, anthracnose, and Phytophthora blight, along with underground part diseases such as Rhizoctonia seedling damping-off, Pythium seedling damping-off, and Sclerotinia white rot. In the 1980s, the sunshade was changed from traditional rice straw to polyethylene (PE) net. From 1987 to 1989, focused research aimed at enhancing disease control methods. Notably, the introduction of a four-layer woven P.E. light-shading net minimized rainwater leakage, curbing Alternaria blight occurrence. Since 1990, identification of the bacterial soft stem rot pathogen facilitated the establishment of a flower stem removal method to mitigate outbreaks. Concurrently, efforts were directed towards identifying root rot pathogens causing continuous crop failure, employing soil fumigation and filling methods for sustainable crop land use. In 2000, adapting to rapid climate changes became imperative, prompting modifications and supplements to control methods. New approaches were devised, including a crop protection agent method for Alternaria stem blight triggered by excessive rainfall during sprouting and a control method for gray mold disease. A comprehensive plan to enhance control methods for Rhizoctonia seedling damping-off and Rhizoctonia damping-off was also devised. Over the past 50 years, the initial emphasis was on understanding the causes and control of ginseng diseases, followed by refining established control methods. Drawing on these findings, future ginseng cultivation and disease control methods should be innovatively developed to proactively address evolving factors such as climate fluctuations, diminishing cultivation areas, escalating labor costs, and heightened consumer safety awareness.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2002.04a
• /
• pp.54-56
• /
• 2002

고추는 국내 재배면적이 노지재배가 75,000 ha 정도로서 해마다 조금씩 감소하고 있고, 시설재배가 5,000 ha 정도로서 해마다 증가하고 있다. 따라서 약 80,000 ha 의 재배 면적을 매년 심어야 하기 때문에 원예작물 가운데 가장 많은 모종을 필요로 한다. 이를 뒷받침하기 위하여 공정육묘에서 차지하는 비율이 60%를 넘고 있다. 고추종자는 발아적온이 28-3$0^{\circ}C$ 정도로 알려져 있으며 발아소요일수가 2-3일 정도로서 발아적산온도는 1,300~1,450$^{\circ}$ 정도로 알려져 있다. (중략)

• Horticultural Science & Technology
• /
• v.35 no.4
• /
• pp.402-409
• /
• 2017

We performed seed germination tests to investigate the effects of seed sowing orientation on germination viability on peanut (Arachis hypogaea L.) sprouts. Specifically, we assessed the influence of seed sowing orientation on germination rate, seedling weight, and seedling length, as well as the seedling vigor index. The seeds were sown in oak tree sawdust at 3.0 cm depth. Four seed orientations were tested: vertical with the hypocotyl end down, vertical with the hypocotyl end up, horizontal with the hypocotyl end down, and horizontal with the hypocotyl end up. The mean seed germination percentages of the four seed orientations were significantly different (p < 0.01) and ranged from 25 to 91.7%. The vertical orientation with hypocotyl-end-down and hypocotyl-end-up orientations showed the highest (91.7%) and lowest (25%) germination rates, respectively. The vertical orientation with the hypocotyl end down produced the heaviest (4.9 g) seedlings and the longest hypocotyls (4.65 cm). This orientation also produced the longest true leaf + epycotyl (2.15 cm) and had the highest seedling vigor index (197.1). The seedlings had a straight growth pattern, whereas seedlings from seeds sown with the hypocotyl up had an awkward plumular hook shape. Taken together, to produce peanut sprouts, we recommend placing the seeds vertically with the hypocotyl end down because this orientation leads to a high germination rate, high biomass production, and high overall seedling quality.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.42 no.2
• /
• pp.12-19
• /
• 2010

This study was carried out to explore the availability of seedling pots made from paper mill sludge using red pepper species called Nokkwang. The seedling pots were made by several conditions such as different mixing ratios between sludge and old newspaper (ONP), sterilizing treatment and latex coating. After 30 day cultivation in a green house, the growth condition of the red peppers was evaluated by comparison with those raised in the plastics seedling pots. The red peppers in the plastics pot showed a better growth than those in the sludge pots. Sterilizing treatment, latex coating and different mixing ratios between paper sludges and ONP did rarely affect a growth rate of the plant and the contents of inorganic elements. However, latex coating contributed to protection of physical structure of the sludge pots in spite of constant water feeding. Even though some inorganic elements from the sludge pots migrated into the bed soils, electronic conductivity of the bed soils was within the proper range for the plant growth. Finally it was confirmed that the seedling pots made from paper mill sludges could be used to cultivate horticultural plants as the alternative to the plastics pots.