• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.32-37
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• 1999

The experiment was conducted to investigate emergence response of lowland weeds at different soil moisture contents, burying depths and upon changes in soil moisture. Rice germination was over 50% at all burying depths under aerobic condition, but the emergence rate of the soil surface placed seeds in saturated and flooded conditions decreased by 19% and 29%, respectively, as compared with that of aerobic condition. Rice seeds at burying depth of over 3 cm did not emerge at all. The emergence rate of Echinochloa crus­galli (L.) Beauv. in aerobic condition was lower than 30%, but the emergence pattern of E. crus galli (L.) Beauv. at different soil moisture contents and seeding depths was similar to that of rice. Emergence behavior of lschaemum rugosum Salisb., Ludwigia octovalvis (Jacq.) Raven and Sphenoclea zeylanica Gaertn. which are dominant lowland weed species in the Philippines also differed depending on soil moisture conditions and burying depths. lschaemum rugosum Salisb. emerged at all burying depths under aerobic condition, whereasLudwigia octovalvis (Jacq.) Raven emerged only at 0 cm deep under saturated and aerobic condition and Sphenoclea zeylanica Gaertn. at 0 cm deep under flooding condition. Weed seeds planted at 1, 3, and 5 cm deep in continuous flooded and saturated condition did not emerge at all, but upon a change of soil moisture condition from saturated to drainage (S$\rightarrow$D) and flooded to drainage (F$\rightarrow$D), grass weeds began to germinate again and the average emergence rate in S$\rightarrow$D and F$\rightarrow$D were 26% and 5% forE. crus­galIi (L.) Beauv., 9% and 8% forI. rugosum SaIisb., respectively. Weed seeds buried in soil in the pot showed great emergence at S$\rightarrow$D but did not emerge under continuous flooded condition. The diversity index accounting for dominance degree and occurrence aspect of weed, was the lowest at F$\rightarrow$D.

• The Korean Journal of Ecology
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• v.23 no.6
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• pp.423-429
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• 2000

To understand the effects of elevated $CO_2$ concentration and temperature on seedling emergence of seven herbaceous species, the seedling emergence was monitored between November 1997 and May 1998 using a temperature gradient chamber and a $CO_2$-temperature gradient chamber. Experiment was conducted under current ambient condition (Control plot), 2$^{\circ}C$-warmed condition with ambient $CO_2$ (T2 Plot), 4$^{\circ}C$-warmed condition with ambient $CO_2$ (T4 plot). and 4$^{\circ}C$-warmed condition with 1.8 fold of ambient $CO_2$ (CT4 plot). Species tested in this study were Digitaria adscendens, Echinochloa crus-galli, Panicum bisulcatum, Setaria viridis. Oenothera biennis, Andropogon virginicus, and Imperata cylindrica. Each species often dominates in the herbaceous stage of secondary succession in Japan. The mean seedling emergence times for all species were significantly increased to 23.6 and 32.2 d in the T2 and T4 plot compared to the Control plot, respectively. The most sensitive and insensitive species in seedling emergence time in T2 plot were O. biennis and D. adscendens, respectivel.y, and those in the T4 and CT4 plot were I. cylindrica and D. adscendens, E. crus-galli and A. virginicus, respectively. All experimental species showed no significant difference in the seedling emergence rate between treatments except for O. biennis and I. cylindrica. O. biennis showed a great decrease in the seedling emergence rate from 83.3% in the Control plot to 38.0%, 14.7%, and 29.3% in the T2, T4, and CT4 plot, respectively. Elevated $CO_2$ had very little effect on the seedling emergence. From these observations, it is expected that increased temperature would greatly advance the vegetative recovery time after disturbance through the advancement of seedling emergence time.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.171-179
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• 2018

We investigated changes of weedy rice emergence and seed condition under different flooding depth condition using 100 accessions of weedy rice germplasm collected in South Korea. In 1 cm of soil buried depth condition, 54 and 57% of emergence was reduced under 5 and 10 cm of flooding depth conditions respectively compared to non-flooding condition. In 5 cm of soil buried depth condition, 66 and 84% of emergence was reduced under 5 and 10 cm of flooding depth conditions respectively compared to non-flooding condition. The 94% of weedy rice germplasm showed less than 10% of emergence rate at 10 cm of flooding depth condition. In flooding condition, seed number, which germinated but did not emerged, was increased. As a result of analyzing the correlation between effective accumulated temperature and seed condition, dead seed rate increased and germination rate decreased depending on effective accumulated temperature. However, emergence rate did not show significant correlation with growth temperature condition under flooding condition such as 5 or 10 cm of water depth, it decreased according to flooding period. In order to reduce the emergence rate of weedy rice, longer than 21 days of flooding might be needed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.27-34
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• 1998

The present study elucidates of the effect of less water stress in different temperature condition on the emergence of forage grasses. Water condition was controlled to 30% and 60% by water content by wet soil. The mean temperature is conducted by $10^{\circ}C$ (out side) and $20^{\circ}C$ (glass house). The results are as follows: 1. Mean emergence time and emergence day after sowing of grasses were greatly influenced by water content of soil and temperature. It was suggested that temperature was very important for the light competition with weed in the early growth of grass. 2. Accumulatied emergence of grasses was nat afected by temperature, but it was sensitively affected by water content of soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.46-51
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• 2004

The film coated snap bean (Phaseolus vulgaris) seeds with five different coating materials treated with 3% increase in seed weight were planted at sandy loam soil controlled moisture content of 18, 19, 20 and 21 %. The oxygen diffusion rate (ODR) was calculated from the different moisture content soil. The number of normal seedlings, seedling vigor, and seedling capability in field (seed vigor x dry matter weight) were observed at 9 days after planting and compared to the changes of ODR. The germination rate and ODR were sharply decreased simultaneously in the seeds planted at 21 % soil moisture content. Seedling emergence did not occur at all as the soil moisture content increased above 22 %. Hence this value should be considered as the threshold of soil moisture content for seedling emergence. An ODR value under 20% did not influence the percent emergence significantly. The certain difference observing in the emergence at the same ODR was not related clearly to the condition of soil. So it can be assumed that the limit of soil moisture content for the emergence of snap bean was approximately 20%. The value of 18% soil moisture content may be considered as the optimum for snap bean emergence. There was close relationship between the mean value of ODR in different soil moisture contents and the emergence. The germination rates of the seeds coated with the different materials were quite different when the seeds were planted at 21 % soil moisture. Dry weight of the seedlings from film coated seeds was decreased slightly, but the germination rates were not much different from the non-treated control under relatively higher soil moisture content (21 %). Major factor lowering emergence rate was oxygen stress while film coating act as a minor constraint for snap bean sown in excess soil moisture condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.502-511
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• 1994

Investigated were the relationships between plumule elongation characteristics and seedling emergence of 98 varieties including native, improved and red rice varieties of Korea, and varieties from U.S.A., Italy, Japan, etc. under proper and excess soil moisture regimes. Under excess soil moisture condition the seedling emergence and establishment rates were much lower in most of the varieties and the seedling emergence rates were delayed substantially in all varieties employed. The seedling emergence rates were lowest in dwarf and some semi-dwarf varieties showing poor plumule elongation under proper soil moisture condition. The seedling emergence and establishment rates were significantly correlated with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes, and with the lower first and second internode length under excess soil moisture condition. Average emergence duration showed significant negative correlation with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes and significant positive correlations with the first and third lower internode length. Based on the standardized partial regression analysis only the variations of mesocotyl and coleoptile length contributed significantly to the varietal difference in seedling establishment rate, and so did the variations of mesocotyl and incomplete leaf length to the varietal differences in emergence speed. In conclusion varieties with greater elongation characteristics of mesocotyl, coleoptile and incomplete leaf are desirable for higher and speedy seedling establishment in dry-direct seeding.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.103-110
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• 2010

This experiment was conducted to investigate seedling emergence and early growth of Monochoria vaginalis and Scirpus juncoides in the controlled-environment chamber maintained at different temperatures. Non-linear regression analyses of observed data against effective accumulated temperature (EAT) with the Gompertz and logistic models showed that the Gompertz and logistic models worked well in describing seedling emergence and early growth of both weed species, respectively, regardless of temperature. EATs required for 50% of the maximum seedling emergence and the maximum leaf number of M. vaginalis were estimated to be 69.3 and $131^{\circ}C$, respectively, while those of S. juncoides were 94.8 and $137^{\circ}C$, respectively. Models developed in this study thus were used to predict seedling emergence and early growth under elevated temperature condition. If rotary tillage with water is made on 27 May under $+3^{\circ}C$ elevated temperature condition, dates for 50% of the maximum seedling emergence and 4 leaf stage were predicted to be 1 June and 15 June for M. vaginalis and 3 June and 14 June for S. juncoides, respectively. As compared with current temperature, these dates are 1-2 days earlier for the seedling emergence and 3 days earlier for the early growth, suggesting that earlier application of herbicides is required for effective control of M. vaginalis and S. juncoides under elevated temperature condition in the future.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.79-84
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• 2001

The experiment were carried out to establish the optimal condition of bulblet size, low temperature treatment and time of incubation in acclimatization on stem emergence of Lilium oriental hybrids. The large size bulblet was better than middle and small size bulblets in percentage of stem emergence and weight of bulblets. The highest percentage of stem emergence was 95% in large size bulblet 'Acapulco' but small size bulblet of 'Casablanca' was no stem emergence. Low temperature treatment(5℃)for breaking dormancy was needed at least more than 9weeks. Weight of bulblets and percentage of stem emergence was not good in 5℃ treatment for 6 weeks. The best stem emergence showed 5 month growing in vitro and the weigh test bulblets during acclimatization of bulblet

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.189-191
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• 2010

The black soldier fly, Hermetia illucens, has a worldwide distribution in the tropics and warm temperate regions and is active in the Korea from May through October. This species colonize a wide variety of decomposing vegetable and animal matter and oviposits in a variety of decomposing materials. In this study, how the black soldier fly pupation, adult emergence and mating rate changed with season at the artificial rearing system was investigated. The black soldier fly larvae and pupae were reared under laboratory condition ($27^{\circ}C$, 60% R.H.). In this study, under the laboratory condition, pupation and adult emergence were not influenced by season, but the data shows definitely different mating numbers throughout whole year. The time of the day is changed with seasons and it influence to mating on artificial rearing. To culture the black soldier fly throughout the year in Korea needs a more deep study under the artificial rearing system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.59-68
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• 1995

Investigated were the relationships between plumule elongation characteristics and seedling emergence of 46 varieties including native, improved and red rice varieties of Korea, and varieties from U.S.A., Italy, India, Japan under 1, 3, and 5cm deep sowing with irrigated and non-irrigated condition. Experiments were carried out in paddy field of sandy loam. There was heavy shower of 19.2mm on the next day of seeding and thereafter, clear and dry weather continued during the experiment period. Soil temperature averaged over 30 days after seeding was $16.4^{\circ}C$ at 3cm depth. Soil hardness increased linearly up to 2.5kg /$cm^2$ on the 14th day after seeding, on which date irrigated plot was irrigated through furrow, and up to 4kg / $cm^2$ on the 28th day in non-irrigated plot. Soil hardness dropped near to 0kg /$cm^2$ after irrigation and developed up to 2.5kg /$cm^2$ again by 28 days after seeding. Seedling emergence was higher in irrigated plots than non-irrigated plots at all seeding depths. Korean improved varieties were substantially lower in seedling emergence under non-irrigated condition of 1 cm deep sowing than those under irrigated condition. This poor seedling emergence resulted mainly from delayed emergence by exposing them to greater soil strength. Percent seedling emergence under irrigated and non-irrigated condition showed signifi-cant correlations at 3 and 5 cm deep sowing. Korean improved varieties belonged to the group of poor seedling emergence, and I taliconaverneco, Chinsura Boro and Weld Pally to best group under both irrigation conditions at 3 and 5cm deep sowing. Seedling emergence showed highly signifi-cant positive correlation with the plumule length of mesocotyl ＋ 1st internode ＋ incomplete leaf and of mesocotyl＋coleoptile. Among the characters constituting plumule length, incomplete leaf length showed greatest positive correlation followed by coleoptile and mesocotyl under irrigated condition at 3 and 5 cm deep sowing, and highest correlation with mesocotyllength followed by first internode and incomplete leaf under non-irrigated condition. Days to 50% seedling emergence at 1 cm deep sowing with irrigation showed great varietal variation of 10 to 30 days, and showed high significant negative correlations with percent seedling emergence under both irrigation conditions except for 1 cm deep sowing with irrigation, Days to seedling emergence revealed sig-nificant negative correlations with plumule characters except 2nd internode, showing highest cor-relation with incomplete leaf length.