scholarly journals Effects of Temperature, Sowing Depth and Soil Hardness On Seedling Establishment and Yield of Cambodian Rice Direct-Seeded in Flood Paddy Fields

2007 ◽  
Vol 10 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Ly Tong ◽  
Tomohiko Yoshida ◽  
Tadanobu Maeda ◽  
Haruki Kimijima
Keyword(s):  
Seedling Establishment ◽  
Paddy Fields ◽  
Sowing Depth ◽  
Soil Hardness ◽  
Direct Seeded ◽  
Effects Of Temperature

scholarly journals Improvement of Seedling Establishment by using Root-elongated Seeds without Coating in Rice Direct-Seeded with a Puddling Seeder

2018 ◽  
Vol 87 (2) ◽  
pp. 140-146
Author(s):  
Keiko Ito ◽  
Hiroyuki Shiratsuchi ◽  
Youichi Ohdaira ◽  
Yoshiaki Kawana
Keyword(s):  
Seedling Establishment ◽  
Direct Seeded

Effect of low temperature and seeding depth on the germination and emergence of seven flax (Linum usitatissimum L.) cultivars

1994 ◽  
Vol 74 (2) ◽  
pp. 247-253 ◽  
Author(s):  
B. J. O'Connor ◽  
L. V. Gusta
Keyword(s):  
Low Temperature ◽  
Linum Usitatissimum ◽  
Seedling Emergence ◽  
Sowing Depth ◽  
Dramatic Effect ◽  
Linum Usitatissimum L ◽  
Percent Germination ◽  
Negative Effect ◽  
Effects Of Temperature ◽  
C 50

Cool, moist soils combined with deep seeding can have a dramatic negative effect on percent emergence and the time to emergence of flax seedlings. The effects of temperature (over a range of 5–15 °C) on seed germination, and seedling emergence from a sowing depth of 20 and 40 mm, were determined for seven cultivars of flax. Temperature had no effect on percent germination; however, the time for 50% of the seeds to germinate at 5 °C was on average 160 h compared with 30 h at 15 °C. The time for 50% of the seeds to germinate at temperatures less than 8 °C was the least for Andro and Vimy and the greatest for Dufferin, McGregor and Norlin. Temperatures less than 10 °C had a dramatic effect on seedling emergence from both seeding depths. On average, fewer seedlings emerged from the 40-mm seeding depth than from the 20-mm seeding depth. The time for 50% seedling emergence at 5 °C was on average 450 h for seeds sown 20 mm deep and 600 h for seeds sown 40 mm deep. In contrast at 15 °C, 50% of the seedlings for all seven cultivars emerged after 150 h from 20 mm and 180 h from 40 mm. At the cooler temperatures and 40 mm seeding depth, Vimy and Andro had the highest emergence rates, while Dufferin and Norlin had lowest emergence rates. This study demonstrates the importance of seeding depths when seeding into cool soils. Also genotypes such as Andro and Vimy are more likely to provide uniform stands when soils are cool and moist and when flax is seeded deep. Key words:Linum usitatissimum L., flax, germination, emergence, low temperature, seeding depth

Elongation habit of mesocotyls and coleoptiles in weedy rice with high emergence ability in direct-seeding on dry paddy fields

2010 ◽  
Vol 61 (11) ◽  
pp. 911 ◽  
Author(s):  
Nam-Jin Chung
Keyword(s):  
Genetic Resources ◽  
Paddy Soil ◽  
Seedling Establishment ◽  
Large Scale ◽  
Soil Surface ◽  
Direct Seeding ◽  
Weedy Rice ◽  
Burial Depth ◽  
Sowing Depth ◽  
Rice Germplasm

Direct-seeding of rice on dry paddy soil could enable large-scale cultivation and cost-savings, but still has some problems including poor seedling establishment caused by low temperature and varied sowing depth. This research was performed to identify weedy rice genetic resources that may help to eliminate the problem of poor seedling establishment in direct-seeded rice on dry paddy soil in temperate regions. The genetic resources screened in this study were 128 genotypes consisting of 92 japonica weedy rices, 24 indica weedy rices, and 12 Korean bred cultivars. On average, weedy rice germplasm had superior abilities to emerge from greater depths than cultivated rices. Coleoptile and mesocotyl lengths were highly positively correlated with the emergence rate. Among the weedy rice germplasm, the japonica weedy rice WD-3 showed the highest level of emergence with the longest coleoptile and mesocotyl. The emergence ability of WD-3 was confirmed in both phytotron and field conditions. In the emerged plants in the field, the mesocotyl elongation increased with increasing burial depth in a logarithmic fashion, and coleoptile extension increased exponentially. The mesocotyl and coleoptile elongated to a length of seed burial depth, indicating that the mesocotyl and coleoptile of WD-3 could induce the safe development of the first leaf of the seedling at the soil surface. Therefore, the elongation habit of the mesocotyl and coleoptile of WD-3 could be one of the most important characteristics for the development of direct-seeding cultivars.

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