• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.269-275
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• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.67-77
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• 1987

To obtain basic information concerning the soybean cultivar differences of physiological and ecological responses to soil pH to select and breed stably higher yielding cultivars, and to improve cultural management of soil differing in pH, the responses of soybean plants in growth, grain yield, nodule formation and its activity, and major chemical compositions of soybean plants were investigated using six cultivars and two levels of soil pH 5 and 7 of the pot and field experimental soil in Suwon, 1985. Acidic soil condition suppressed overall vegetative growth of soybean plants and thereby decreased stem length, number of nodes, leaf area, dry weight of the plants, root activity, nodulation and nodule activity, the content of allantoin nitrogen, total nitrogen, phosphorous, calcium, and magnesium of the plants. Due to the such responses of soybean plants to the acid soil, grain yield also decreased along with less grains per plant. However, the little difference in growth and yield of the cultivar Janbaeglcong in response to soil pH is considered to be a good source of breeding materials tolerant to acidic soil condition. In this regard Bongeui and Oialkong also were relatively stable in the growth and grain yield under the different soil acidity conditions.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.181-189
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• 1979

In order to establish fertilizing technique for the increase of grain yield and its stability, the total absorbed amount of nutrients and nutritional status of rice plants at different growth stages were studied with respect to the nutrient contents and its relation to grain yield and yield components. This experiment was carried at three different level of nitrogen fertilization; two different seeding and transplanting times, and eight cultivars including both Japonica-and Tongil-type. The results of a part of these experiments are summarized as fallows: 1. The culm length tended to Increase with increasing fertilizer amount, but no significant difference between ordinary and heavy fertilization was observed in Tongil-type cultivars. 2. The panicle length was some what longer in ordinary and heavy fertilization than non-fertilization. 3. As the N-fertilizer level increases, the number of panicles per plant increased with higher response in Japonica-type cultivars than in Tongil-type cultivars. 4. The number of grains per panicle increased significantly in ordinary and heavy fertilization, compared to non-fertilization, but the difference in grain number per panicle among fertilizer treatment was smaller in Japonica-type cultivars than Tongil-type. 5. The 1,000 grains weight showed no significant difference among fertilization levels in ordinary transplanting, but indicated gradual decreasing tendency as the transplanting delayed. 6. In percentage of ripeness, there was no significant difference in ordinary transplanting, but hightly significant in late transplanting among N-fertilization levels and cultivars. 7. In yield, highly significant difference was shown among N-fertilizer levels and cultivars In Tongil-type variety, higher yield was obtained in ordinary fertilization than heavy fertilization. 8. The straw weight showed the tendency to increase in higher nitrogen level, but no significant difference between ordinaly and heavy fertilization was observed in Tonsil-type cultivars.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.110-123
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• 1992

To investigate the safening effect of dymron against cinosulfuron, the responses of 104 rice cultivars and lines to single and mixture treatments of cinosulfuron [3-(4.6-dimethoxy-1,3,5-triazin-2-yl)-1-[2-(2-methoxyethoxy)-phenylsulfonyl]-urea] and dymron [1-(${\alpha}$, ${\alpha}$-dimethylbenzyl)-3-p-tolyl urea] were evaluated. The responses of 104 rice cultivars and lines to cinosulfuron were differed. Among the rice cultivars, growth of Calrose, Dasukei, Hwajinhyeo, and Milyang 105 was significantly inhibited by cinosulfuron but there was no inhibition in Daeseongbyeo, Iri 371, Jangseongbyeo, Taebaegbyeo and IR 74. The japonica types were generally inhibited more than the indica and indica${\times}$japonica types. When Kwangmyungbyeo was treated with the mixtures of cinosulfuron 48g and 96g ai/ha with dymron 450g ai/ha, the inhibition of plant height was significantly reduced regardless of dymron concentrations. With increase in cinosulfuron concentration, the safening effect of dymron against cinosulfuron was more evident in plant height than fresh weight. On the other hand, dymron did not have any safening effects of cinosulfuron on Echinochloa crus-galli at any concentrations. The mixtures of dymron and cinosulfuron produced antagonistic effects on the plant height regardless of rice cultivars and treatment concentrations. At cinosulfuron 24g ai/ha, the effects of the mixtures of cinosulfuron and brassinolide on the plant height of Kwangmyungbyeo and IR 74 were similar irrespective of brassinolide concentrations but the inhibition of Kwangmyungbyeo was greater than that of IR 74 as the concentrations of cinosulfuron increased. The effects of the mixtures of cinosulfuron at concentration of 96g ai/ha with various ABA levels on the plant height of both Kwangmyungbyeo and IR 74 showed synergistic effect regardless of ABA concentration. However, the response of fresh weight of both cultivars treated with cinosulfuron at 96g ai/ha with ABA synergisism was observed in Kwangyungbyeo while IR 74 showed antagonism.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.190-200
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• 2021

The heading response of rice varieties, originated from South Korea, North Korea, and northern China, was examined under the temperature and day-length conditions of 10 low-temperature regions in North Korea. When 30-day-old broadcast tray-raised seedlings (BS) were used, only one or a few varieties reached the heading stage within the safe marginal heading date (SMHD) under the Hamhung, Pyonggang, Huichon, and Kanggye conditions. In the Yangdok and Sinpo environments, no varieties reached heading until SMHD. The South Korean varieties that reached the heading stage between SMHD and late marginal heading date (LMHD) were Jinbuol, Baegilmi, Joun, Jopum, Jinok, Jopyeong, Sanhomi, and Odae for the Hamhung, Pyonggang, Huichon, and Kanggye; Joun for Sinpo; and none for Yangdok, Kimchaek, Sonbong, and Chunggang environments. The number of days to heading (DTH) was positively correlated among all 10 regions. Reduced DTH in the 30-day-old pot tray-raised seedlings (PS), compared to BS, was not consistent with varieties and regions. Reduced DTH in PS, compared to BS, was the largest in Jinok and Sonbong9 among the South and North Korean varieties, respectively, whereas it was small in the northern Chinese varieties. The South Korean varieties that headed until SMHD in PS were Jinok for the Hamhung, Pyonggang, Yangdok, Sinpo, and Kanggye environments; and Jinbuol, Jopum, and Jinok for the Huichon condition. In the Kimchaek and Chunggang conditions, Jinok reached the heading stage within LMHD. With the use of PS for some responsive varieties such as Jinok, varietal adaptability could be improved to the conditions of low-temperature regions in North Korea. None of the PS or BS among the tested varieties reached the heading stage until LMHD for the Chongjin and Sonbong conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.1-35
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• 1969

Attempts were made to obtain the fundamental knowledge on the quantitative constitution status of leaves and stem of elongating node-part, and the relationships between these morphological characteristics along with the nitrogen contents of leaves and grain yield were examined varing application amounts of nitrogen in rice plant. I. The agronomic characteristics of leaves and nodes of elongation node-part (4-node parts from the top of stem) were observed at heading stage with 20 leading rice varieties of Kang Won district. The results are summarized as follows: 1. Leaf area magnitude of the flag and the fourth leaf was smaller than that of the second and the third with the average value of flag leaf 18.61 $cm^2$, the second leaf 21.84 $cm^2$, the third 21.52 $cm^2$ and the fourth 18.56 $cm^2$. The weight of leaf blade showed an isotonic tendency with the magnitude of leaf area with the value of the flag leaf 97.0 mg, the second leaf 117.1 mg, the third 115.4 mg, and the fourth 95.3 mg. The weight of each leaf sheath was remarkably larger at the higher node-part than at the lower node-part of the stem with the value of flag leaf sheath 176.3 mg, the second 163.7 mg, the third 163.4 mg and the fourth 123.9 mg. Accordingly, the total leaf weight of each part was larger at the second and the third leaf than at the first and the fourth. Total plant weight of each part (weight of leaf blade, leaf sheath, and culm) also was larger at the middle node-part. 2. Coefficients of variation for the varietal differences of the morphological characteristics of elongating node-part were 12.75% for the leaf area, 15.29% for the weight of leaf blade, 15.90%, for the weight of leaf sheath, 11.42% for the weight of internode, 15.45% for the leaf weight (leaf blade ＆ leaf sheath) and 13.24% for the straw weight. And these coefficient values of the most characteristics were, on the whole, smaller at the second and the third node-part than at the first and the fourth node-part, but the coefficient value of the internode weight was rather small at the third and fourth node-part. 3. Constitutional ratio of each plant organ to the total plant weight in term of dry matter weight (excluding head and root wight) was 39.2% for the leaf sheath, 34.2% for the culm, 26.6% for the leaf blade. And ocnstitutional ratio of leaf sheath in term of dry matter weight was larger at the higher position in contrast with that of culm. 4. Average weight ration of leaf blade to culm, leaf sheath to culm, leaf blades to sheath and the leaf blades to culm plus leaf sheath were 77.7 %, 114.5%, 67.9% and 36.2%, respectively. With regard to the position of the plant organ, the weight ratio of leaf blade to culm and that of leaf sheath to culm were larger at higher part in contrast with that of leaf blade to leaf sheath. 5. Generally, there founded deep relationships between grain yield and each morphological characteristics of plant organ of elongating node-part as follows; Correlation coefficient between total area of 4 leaves (from flag to the fourth leaf) and grain yield was ${\gamma}$=0.666$^{**}$ In regard to the position of leaves, correlation coefficient values of flag, the second, the third and the fourth leaf were ${\gamma}$=0.659$^{**}$, ${\gamma}$=0.609$^{**}$, ${\gamma}$=0.464$^{*}$ and ${\gamma}$=0.523$^{*}$, respectively. Correlation coefficient between total weight of leaf blades and the grain yield was ${\gamma}$=0.678$^{**}$. In regard to the position of leaves, that of flag leaf was ${\gamma}$=0.691$^{**}$, and ${\gamma}$=0.654$^{**}$ for the second leaf, ${\gamma}$=0.570$^{**}$ for the third, and ${\gamma}$=0.544$^{**}$ for the fourth. Correlation between the weight of leaves (blade weight plus sheath weight) and the grain yield showed similar values. In the relationship between plant weight and grain yield there also was significant correlation, but with highly significant value only for the first node-part. There appeared correlation between total weight of leaf sheath and grain yield with the value of ${\gamma}$=0.572$^{**}$ and in regard to the position of each leaf sheath the values were ${\gamma}$=0.623$^{**}$ for the flag leaf, ${\gamma}$=0.486$^{**}$ for the second leaf, ${\gamma}$=0.513$^{**}$ for the third, ${\gamma}$=0.450$^{**}$ for the fourth. However, there was no significant correlation between culm weight and grain yield. 6. With respect to in gain yield, varietal differences in magnitude of leaf area, weight of leaf blade, leaf weight per unit area, weight of leaf sheath, culm weight, total leaf and stem weight were larger in the case of high yielding varieties and decreased in accordance with decreasing yield. And this tendency also was shown in the varietal differences of magnitude of each part. Variation in magnitude of each part for the leaf area, weight of leaf blade, culm weight was significantly small in high yielding varieties compared to low yielding varieties. 7. Plant constitutional ratio of each organ of the elongating node-part in term of weight magnitnde varied to som extent according to varieties indicating leaf blade 27.6%, leaf sheath 39.5%, culm 32.9% in the case of high yielding varieties, leaf blade 25.5%, leaf sheath 38.1%, culm 36.4% in the case of low yielding varieties, and medium yielding varieties showed intermadiate values. 8. Far higher values of the weight ration of leaf blade to culm and leaf sheath to culm were given to the high yielding varieties compared to low yielding varieties. And medium yielding varieties showed intermadiate values. II. Effects of application rate of nitrogen on the morphological characteristics of the elongating node-part, nitrogen content of leaf blade, and their relation with the grain yield of the rice were observed with 3 rice varieties; Shin No.2, Shirogane, and Jinheung varying application amounts of nitrogen as 8kg, 12kg and 16kg per 10 are. 1. As for the variation of morphological magnitude s affected by the amounts of nitrogen application, total leaf area (4 leaves from the flag leaf) increased to 16.5% at 12kg N plot, and about 30% at 16kg N polt compared to 8kg N plot and total weight of leaf blade also increased to similar extent, respectively, in contrast with weight of leaf sheath increasing 4.9% and 7.8%, respectively. However, the weight of culm decreased to 1.5% and 11.2%at the 12kg N plot and 16kg N plot, respectively, and these decreasing rate was noted at the nodes of lower part. 2. As for the verietal differences in variation of morphological magnitude as affected by the amount of nitrogen fertilization, leaf area coefficient value of variation of the total leaf area was 15.40% for Shin No. 2, 12.87% for Shirogane, and 10.99% for Jinheung. With respect to the position of nodes, the largest variation of leaf blade magnitude was observed at the fourth for Shin No. 2, the second for Shirogan, and flag leaf for Jinheung. And there also was an isotonic varietal difference in the weight of leaf blade. Variation in total culm weight showed varietal differences with the coefficient value of 7.72% for Shin No.2, 12.11% for Shirogane, and 0.94% for Jinheung. There also was varietal differences in the variation according to the position of nodes. 3. Variation of each elongating node-part related to the fertilization amount decreased with the increase of fertilization amount in the items of leaf area, weight of leaf sheath, culm weight, but weight of leaf sheath varied more at heavier fertilization than at others. 4. Constitutional ratio of each organ excluding head also varied with fertilization amount; constitutional ratio of leaf blade increased much with the increasing amount of fertilization in contrast with the response of culm eight. However, constitutional ration of the weight of leaf sheath was not much affected. 5. Lower value of the ration of leaf blade to culm was given to the 8kg N per 10 are plot, and the ratio of leaf blade to leaf sheath decreased with the increasing amount of fertilization in contrast with the increase in the ratio of leaf sheath to culm. however, the ration of leaf blade to culm plus leaf sheath decreased. 6. With the increase of nitrogen fertilization, leaf area, weight of leaf blade and leaf sheath increased. Accordingly, grin yield also increased to some extent. It was noted that culm weight was changed inversely to the changes in grain yield, but the degree of this variation varied with varietal characteristics. 7. Nitrogen content of leaves at heading and fruiting stage varied with the fertilization amount, and average nitrogen content of leaves of the varieties used 2.19%, 2.49% and 2.74% at the plot of 8kg N, and 12kg N and 16kg N per 10 are, respectively, at heading time, and 0.80%, 0.92% and 1.03% at each plot at fruiting stage. Thus, nitrogen content of leaves increased much with the increasing amount of fertilization, and higher value was given to the leaves on the higher position of elongating node-part. 8. There also was variation of nitrogen content of leaves in accordance with the varieties. However higher grain yield was obtained from the plants retaining higher nitrogen content in leaves at heading or fruiting stage.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.35-40
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• 1983

This study was conducted to obtain basic informations for growth regulators on occurrence of sucker in tobacco plants (Nicotiana tabacum L.). Varieties used were "hicks" and "kusaga mammoth" and growth regulators such as MH(maleic hydrazide), GA(Gibberellic acid) and BA(Benzyl adenine) were used. Immediately after topping, an application of maleic hydrazide at 900g a.i./ha completely inhibited sucker development, but sucker were developed as the rates of MH decreased, in both varieties. In nontopped tobacco plants, the similar trend as in the topped plant was observed except for no sucker development in the untreated control. Any combination of GA and BA under presence of MH had no effects on sucker development in the topped tobacco plants. However, in the nontopped plants, sucker were observed when the combined ratio of BA and GA was 10 to 1 under the presence of MH standard level. The highest no. of sucker was obtained when combined BA $10^{-5}M$ with GA $10^{-6}M$ under the presence of MH, showing higher response of hicks than that of kusaga mammoth. A single application of GA and BA in the topped plants markedly increased sucker number as GA concentrations increased showing varietal difference. GA $10^{-4}M$ increased sucker number as high as as 42% for hicks, but inhibitory effect on kusaga mammoth in comparision with the untreated control, showing very effective on hicks. BA showed the similar effect like GA. Combinations of GA and BA showed antagonistic effect on sucker development. The length of sucker was markedly promoted as the GA rates increased, and the promotive effect of sucker length by GA was not nullified by the addition of BA. But combination treatment of GA and BA mostly resulted in less dry weight than the untreated control, indicating that sucker developed from the combined treatments of GA and BA were not normal and kusaga mammoth was more affected by them.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.36-46
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• 1988

Twelve soybean cultivars were cultivated in the 1/2,000a. Wagner pots with irrigation and without irrigation for 30 days after flowering, and the differences of plant growth and bean yield among cultivars were compared. And to investigate the varietal differences in the rate of photosynthesis under different relative humidity, 6soybean cultivars were cultivated in 1/2,000a. Wagner pot and the rate of photosynthesis of each soybean cultivar at flowering time was measured under the relative humidity of 80, 70, 60, 50 and 40%. The results obtained are summarized as follows; 1. The days to maturity of the soybean cultivars were shortened by non-irrigation treatment. The response of the maturing dates to non-irrigation was significantly different among the soybean cultivars. The days for maturing of Paldal, Danyeob and Eundaedu were delayed 2 days but those of Jangbaek and Tamahomare were delayed about 7 to 8 days under non-irrigation treatment. 2. The stem length, stem diameter, number of nodes of the mainstem, number of branches and number of branch nodes of all soybean cultivars were decreased by non-irrigation treatment. The number of branches and the number of branch nodes were especially severely influenced by non-irrigation treatment. 3. The number of pods per plant and the number of perfect pods was significantly reduced by non-irrigation treatment but the number of imperfect pods was increased. The non-irrigation treatment reduced the number of pods per plant by 58.0% and the ratio of the number of the perfect pods per plant by 46.6% relative to the ordinary cultivation with irrigation. 4. The grain yield of all cultivars was significantly reduced by the non-irrigation treatment, and average grain yield of soybean cultivars cultivated under non-irrigation treatment was 35.9% of that of soybean cultivars cultivated with irrigation. The influence of non-irrigation treatment was lowest in Paldal and significantly high in Tamahomare and Jangbaek. 5. The rate of photosynthesis of soybean leaves was significantly different among cultivars and was also influenced by relative humidity. Ratio of the photosynthetic amount of soybean leaves at 40% RH to the maximum photosynthesis at optimal humidity was 97.2% in Paldal, 96.4% in Danyeob and 88.8% in Baekun. 6. At 40% relative air humidity, highly significant correlations were found among the photosynthesis rate, the amount of transpiration and the respiration rate.

• Journal of Sericultural and Entomological Science
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• v.47 no.2
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• pp.51-55
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• 2005

Resveratrol is naturally occurring phytoalexin compounds produced by grape berries, peanuts, and their products in response to stress such as fungal infection, heavy metal ions or UV irradiation. The objective of this study was to develope a reliable high performance liquid chromatographic (HPLC) method for the quantitative determination of trans-resveratrol in mulberry fruit. Samples were extracted in 80% MeOH and filtered with $0.45{\mu}m$ syringe filter. The transresveratrol was separated Waters $C_{18}$ column, using a mobile phase containing 0.025% trifluroacetic acid in 5% acetonitril and 0.035% trifluroacetic acid in 50% acetonitril, detected by photodiode array detector (PDA) at 254 nm and the flow rate was 1ml/min. Under this analytical condition, the mean content of mulberry fruits (fifty varieties) was $777.3{\pm}585.9ppm$. Among the tested samples, 'Mansaengbaekpinosang (II)' was the highest level in 3450.6 ppm. However four accessions including 'Gukbu', 'Sabangso (I)', 'Simseol' and yield mulberry fruit were not able to detected. Eight suitable varieties selected for the production of fruit were 'Jeolgokchosaeng (Chungbuk)' 777.8 ppm, 'Dangsang 7' 771.1 ppm, 'Jangsosang' 133.9 ppm, 'Susungppong' 31.1 ppm, 'Suwonnosang' 639.7 ppm, 'Palcheongsipyung' 1475.9 ppm, 'Kangsun' 864.0 ppm, and 'Jukcheonchosaeng' 1458.5 ppm. 'Daesungppong' which was the first authorized variety for the production of mulberry fruit was 1236.7 ppm. In conclusion, these results suggest that mulberry including fruit and leaf may a good new resource for resveratrol production.

• Research in Plant Disease
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• v.17 no.1
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• pp.19-24
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• 2011

It was identified as a sharp eyespot (Rhizoctonia cerealis) that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A) (KACC 40106). They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as $20{\sim}25^{\circ}C$ and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including 'Anbaekmil', however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, 'Tapgolbori', 'Albori' and 'Seodunchalbori', showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.