• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.434-439
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• 2008

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.

• 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.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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.305-310
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• 2002

The performance of 7 sugary (su) and 12 shrunken-2 (sh2) sweet com hybrids which are commercially grown in the United States was tested in Korea. The 100-seed weight of su hybrids (16.5-23.6 g) was much heavier compared to that of sh2 hybrids (10.9-17.5 g). The germination rate of su and sh2 hybrids at $25^{\circ}C$ ranged 93.3-100% and 86.7-98.9%, the emergence rate of su and sh2 hybrids in cold test ranged 78.9-97.8% and 62.2-97.8%, and field emergence rate of su and sh2 hybrids ranged 74.4-100.0% and 79.9-98.2%, respectively. In su hybrids, there was a significantly positive correlation between germination rate at $25^{\circ}C$ and emergence rate in cold test or early growth. In contrast, in sh2 hybrids seed weight was positively correlated with early plant growth, while not with the germination rate at $25^{\circ}C$ or emergence rate in cold test and field. Most sh2 hybrids produced larger and more marketable ears compared to su hybrids although there were significant differences among the hybrids in the same genotype. At harvest (24 days after pollination) soluble solids content of su hybrids (24.3-27.1 Brix %) was much higher than that of sh2 hybrids (13.8-18.0 Brix %), while total sugars of sh2 hybrids (21.4-28.6% on the dry weight basis) was much higher compared to su hybrids (2.4-15.9%). Considering germination and emergence rates, marketable ear production, and total sugar content, 'GCB 70' and 'Sweet Satin' in su hybrids and 'Ice Queen', 'Aspen', 'Sweet Magic', 'Bandit', 'Xtrasweet 82', 'Aspen', and 'Cambella 90' in sh2 hybrids performed better than other hybrids.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.381-388
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• 2004

In Korea, production of super sweet corn has been economically feasible and is substituting for traditional sweet corn due to better flavor in recent years. Major limiting factors for super sweet corn production are low field emergence and low seedling vigor. The optimum water potential (WP) for the priming of normal and aged seeds of dent, sweet (su) and super sweet (sh2) corns was studied to improve low seed quality. Seeds were primed at 0, -0.3, -0.6, -0.9, and -1.2 MPa of polyethylene glycol (PEG) 8000 solution at $15^{\circ}C$ for 2 days. Priming effects differed depending on the type of corn, seed quality, and WP of PEG solution. Although WP of priming solution did not influence the emergence rate of extremely high quality normal dent corn seeds, it reduced time to $50\%$ emergence (T50) and increased plumule weight. In contrast, the emergence rate of aged field corn was improved by seed priming at 0 MPa and plumule weight and $\alpha-amylase$ activity was enhanced. The optimum WP for both normal and aged sweet and super sweet corn seeds was between -0.3 and -0.6 Mpa. At the optimum WP emergence rate, $\alpha-amylase$ activity, and content of DNA and soluble protein increased, while T50 and leakage of total sugars and electrolytes reduced.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.134-137
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• 1999

An experiment was carried out to determine the effects of priming and growth regulator treatment of seeds on the emergence and seedling growth of rice, Oryza sativa L. (cv. 'Ilpumbyeo'). Normal seeds were primed in a -0.6 MPa polyethylene glycol solution at 15$^{\circ}C$ for four days with air-bubbling. Then both primed and non-primed seeds were soaked in water, 100 ppm GA$_3$, 2 ppm ABA, and 10 ppm kinetin solutions for 24 hours. The seeds were planted in soil at 3 and 5 cm depths and allowed to germinate in a growth cabinet at 2$0^{\circ}C$. Generally, the emergence rate at the 3 cm seeding depth was higher and emerged faster compared with the 5 cm seeding depth. The emergence rate of primed seeds was higher and emerged faster compared to non-primed seeds. GA$_3$ and kinetin treatments were the most effective to improve the emergence rate of non-primed seeds. Coleoptile length at the 5 cm seeding depth was longer than that at the 3 cm seeding depth. Leaf number, plant height, and root length of primed seedlings were higher compared with non-primed seeds. GA$_3$ promoted the elongation of plant height and mesocotyle length.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.20-26
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• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.185-189
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• 2021

This study was conducted to determine and to standardize the time of emergence of Protaetia brevitarsis adults, through four breeding experiments, including one which selected the dominant individuals of Protaetia brevitarsis. The breeding experiments were divided into two groups with hibernating and non-hibernating Protaetia brevitarsis by placing 100, 150, 200, 250 and 300 Protaetia brevitarsis in each breeding box (50 cm × 35 cm × 15 cm) filled with 12 L of fermented sawdust. Breeding tests were with four replicates each for 3 months. The test period was classified into four stages: Exp. 1 (Sep 1, 2019 to Nov 30, 2019), Exp. 2 (Dec 1, 2019 to Feb 29, 2020), Exp. 3 (Mar 1, 2019 to May 31, 2020) and Exp. 4 (Jun 1, 2020 to Aug 31, 2020). The survey items included average dead number, average emergence number, average mortality, and average emergence rate. In Exp. 1 and 2, the changes in Protaetia brevitarsis adults were similar. In Tables 1 and 2, the allegorical changes of adult white-spotted flowers were similar. In addition, the average dead number, average emergence number, average mortality, and average emergence rate showed better results in the hibernation state than in both Exp. 1 and 2. Exp. 3 and 4 showed a pattern of change different from the results of Exp. 1 and 2 and these characteristics were superior in the hibernation states compared to the non-hibernation states. In conclusion, this result was found to be most appropriate as a standardization of the emergence time of 200 Protaetia brevitarsis treatments through four breeding experiments in the hibernating state.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.2
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• pp.82-87
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• 2002

The purposes of this study are to investigate water content and treatment period in Solid Matrix Priming(SMP; method for enhanced rapid and uniform seedling emergence in tobacco seeds). The higher water content made the faster imbibition speed of tobacco seed. But the radicle emergence shorten the period of water equilibrium. The range of water content in SMP treatment within the limits of no radicle emergence of tobacco seed was 28∼32% to dry weight of tobacco seed. The rate of radicle emergence and seedling emergence was higher in water content 30% and 40% treatment plot than that in 50% and 60% treatment plot. But it was not different between SMP treatment and non-SMP treatment. In water content 40% during 9 days treatment, germinative energy was highest, and T50 and mean germination time(MGT) were the shortest. The germination speed was higher in SMP treatment than that in non-SMP treatment. It was not different on the germination rate between non-SMP treatment and SMP treatment.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.183-187
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• 1992

This study was conducted to evaluate the effect of systematic herbicide application and polyethylene(PE) film mulching in direct seeded Angelica gigas Nakai. Freshly-collected-seed showed 86% of emergence rate and required 18 days of emergence duration. Cold treatment of seeds increased emergence rate by more than 90% and shortened 2 days of emergence duration. Paraquat) 1,1'-dimethyl-4,4'-bipyridylium dichloride was the most effective when applied just before emergence of A. gigas and provided 96% of emergence rate and 91% of weeding effect when applied 23 days after seeding. Soil applied herbicides used did not cause any phytotoxicity on emergence with application of 2-fold recommended rate and gave more than 90% of weeding effect. Black PE film mulching gave excellent emergence rate and weeding effect, and shortened emergence duration by 8 days.