• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.96-102
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• 2003

This study was conducted to determine the effects of two plant populations (28 and 14 plants per $m^2$) and two toppings in conventional plant population (28 plants per $m^2$) on soybean (Glycine max L. cv. Pungsannamulkong) cultivated in the paddy field. The two topping time were taken at 6$^{th}$ to 7$^{th}$ and 8$^{th}$ to 9$^{th}$ trifoliolate leaf stages in the conventional plant population. Experimental design for growth data was a randomized complete block with three replications, and samples were taken at R1 (July 31), R3 (August 19), R5 (September 2) and R7 (September 23) growth stages. The branch number of soybean was relatively higher in the low plant population (14 plants per $m^2$) and with the topping at the 6$^{th}$ to 7$^{th}$ leaf stage, in the conventional plant population (28 plants per $m^2$), and with topping at the 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage in descending order. The highest average branch length of soybean was observed in the low population and the longest branch length was observed from the soybean with topping at the 6$^{th}$ to 7$^{th}$ leaf stage. The leaf number per plant was decreased in order of in the low population, with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage, with the topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage, and in the conventional population. The leaf area was high in the low population and with topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with the topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage in soybean. The dry weight of leaves and branches was high in the low population and with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage. The leaf number per plant was high in the low population and with topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage. The grain yield per 10a was high with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.169-178
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• 1984

This study was conducted to investigate the influence of the topping time and height on the nonvolatile organic and higher fatty acid contents and the correlation among acid contents of tobacco plants. Within the topping time, the flowering (normal) stage of topping was the lowest in total analyzed acid (TAA), total nonvolatile organic acid (TNOA) and magic acid contents of NC2326, however, the highest in those of Burley 21 on 30 days after budding. Total higher fatty acid (THFA) and linoleic acid contents tended to be low with normal stage of topping. The lower the topping height, the lower the TAA, THFA and linoleic acid contents in middle and upper leaves (or NC2326 and Burley 21 were observed. On the other hand, the lower the topping height, the lower the TNOA and malic acid contents in middle and upper leaves for Burley 21 and upper leaves for NC2326 were found. There was a significant positive correlation between magic acid and TNOA contents. Similarly, TAA content showed a significant positive correlation with TNOA, oxalic acid and citric acid contents. But there was a negative correlation between malic acid and THFA contents. There were highly positive correlations among oleic acid, linoleic acid and THFA contents, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.23-30
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• 1988

This experiment was carried out to obtain the basic information for the improving of leaf quality by topping time and depth in flue-cured tobacco. Development of palisade parenchyma and spongy parenchyma were in order of button stage＆gt;early flower stage＆gt;late flower stage by topping time, and were in order of 4th leaf topping from floral axis＆gt;2nd leaf topping from floral axis＆gt;floral axis by topping depth. When 2nd leaf from floral axis were topped at late flower stage in A grade field and at early flower stage in B grade field, total sugar to nicotine ratio ralating to organoleptic characteristics were desirable as 9.0 and 9.7, and petroleum ether extract contents relating flavor of flue-cured tobacco were high as 9.9% and 8.4%, respectively. In ecological tissue, percentage of direct effect on quality were 43.2% in palisade parenchyma. 26.5% in spongy parechyma. 17.7% in tissue ratio, 6.7% in leaf thickness, 3.1% in intercellular space, 2.8% in leaf type and in chemical components, were 40.6% in nicotine. 35.7% in T-sugar/nicotine, 10.0% in total sugar, 7.0% in T-nitrogen/nicotine, 4.6% in total nitrogen, 2.1% in petroleum ether extract. The optimum topping depth were desirable at topping under second leaf from floral axis at late flower stage in A grade field and at early flower stage in B grade field for good leaf quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.146-150
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• 2011

A large amount of nitrogenous compounds are found in burley tobacco and are responsible for peculiar aroma during smoking. Excess in nitrogen or its compounds such as total nitrogen and proteins in burley tobacco gives a strong pungency and make its taste bad. The present study has focused on improving quality of Burley tobacco by regulating topping and harvesting time of leaf to reduce nitrogen compounds in Burley tobacco. In addition, the early-stage of flower topping had lower level of nitrogenous compound, such as total nitrogen and protein nitrogen, and total tobacco-specific nitrosamine (TSNA) contents compared to the button-stage and full flower-stage topping. Also, the contents of nicotine got significantly decreased while the ether extract was increased as the period of topping got delayed. Regarding the brightness among the colors of cured leaves, the color at the full flower-stage topping was the brightest, and there was no particular difference in red and yellow colors. The harvesting amount was decreased as the period of topping got delayed and there was no significant difference between the topping treatments in terms of the exterior quality. As the harvesting time delayed, the total nitrogen, protein nitrogen, nitrate nitrogen, and ammonium nitrogen were decreased while the nicotine contents got increased. Also, the total TSNA contents were decreased as the harvesting time delayed. However, ether extract was increased. Among the colors of cured leaves, the brightness and degree of yellow color were significantly increased as the harvesting time delayed, and there was no particular difference in the degree of red color. The harvesting amount was decreased along with the delayed harvesting time; however, the harvest of the matured and mellow leaves was higher in terms of price, compared to that of the immature leaves. For the reduction of nitrogenous compound and TSNA contents in Burley tobacco, the topping was examined to be more effective in terms of improvement in chemical contents and quality regardless of the decreased harvesting amount.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.155-162
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• 1982

This study was conducted to investigate the effects of topping time and degree on the characteristics of three tobacco varieties, and to establish the early topping (Button stage) method at Eumseong Experiment Station, Korea Tobacco Research Institute in 1979-1980. The results are summarized as follows; yield increased in the plots of By 104, topping at button stage and under first leaf from floral axis. Quality was good in the plot topped at button stage and under first leaf from floral axis. Price per l0a was highest in the plot topped at button stage and under first leaf from floral axis.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.1
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• pp.5-11
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• 2001

Experiments were conducted to evaluated the sucker control efficiency of several suckercides and their combinations for flue-cured tobacco in Korea. In 1999, Flumetralin(Prime+, P+), Butralin(B), Fatty alcohol(FA, n-decanol 85%), pottasium salt of maleic hydrazide(MH), tank mix of MH with P+ (MH·P+), and another tank mix of MH with FA(MH·FA) were applied after topping, respectively, then sucker number and sucker dry weight were investigated on the 30th and 50th day from treatment. Sucker number and dry weight were significantly lowered by P+, B, FA and MH·P+ applications compared with those of MH and MH·FA for both investigated periods. A significant reduction in sucker number and dry weight was observed in P+, B, and MH·P+ applications. FA treatment was not so much effective in sucker control as P+. In 1999 and 2000, several suckercides and tank mixes of their combinations were applied first at button stage and second after topping, respectively, to compare the effects of sucker control on yield, price index and chemical components of cured leaves. Compared to the standard method of FA 30x at button stage followed by MH40x application after topping(FA 30x + MH 40x), sucker number and dry weight decreased by [FA 30x (or P+ 1%] or [FA 30x(or B 1.5%) + MH 60x·B 1.5%] treatments, even at reduced MH levels. But yield, price index and chemical components of cured leaves were not differed among treatments.

• Research in Plant Disease
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• v.10 no.2
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• pp.150-153
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• 2004

This study was conducted to investigate the sap transmission pattern of CGMMV and to select the disinfectant of sap transmission on watermelon cultivation. Being investigated CGMMV occurrence change after transplanting two diseased plants among 47 plants on the watermelon house, disease spread rapidly from early growth stage of 4 % to late growth stage of 83 %. When the grafting knife and topping scissor was dipped onto the several disinfectants before grafting or topping, disease suppressed 87-95 % on whole milk, skim milk, tri-sodium phosphate, and sodium hypo-chloride solution. Disinfection effects of 88.2 % and 91.2 % on whole milk and skim milk were showed when the hand dipped on the disinfectants.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.1
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• pp.66-74
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• 1981

This study was conducted to investigate the interaction between chemical compositions and agronomic characteristics of perique tobacco leaf. At the topping stage, the thickness of leaf was positively correlated with total sugar($\textrm{0.975}^{**}$), reducing sugar($\textrm{0.975}^{**}$), alkaloid($\textrm{0.518}^{*}$) and petroleum ether extract($\textrm{0.801}^{**}$) contents. The length of upper leaf was negatively correlated with its chemical contents. Total sugar contents of the harvested leaf showed a sigmoid pattern of distribution along the leaf stalk positions.

• Journal of Plant Biology
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• v.15 no.2
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• pp.1-6
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• 1972

Cultivar Yeollow Special A, the most leading Korean economic leaf tobacco in Korea, were field-cultivated in four different localities of Korea for the period of two years (1970 and 1971) and sprayed at varied levels of 2-chloroethyl phosphonic acid (CEPA) for foliar application few days after topping. While no striking difference in leaf yield by weight was obtained among the treatments when compared with control, leaf quality as expressed for shipment price in won tended when compared with control, leaf quality as expressed for shipment price in won tended to improve. The treated leaves with 300 to 900 ppm of CEPA (approximately 140 1/acre of 500 ppm) not only showed yellowing and accelerated maturity to pick 4 to 5 days with practicable optimal level earlier than control, but also speeded up to take nearly with practicable optimal level earlier than control, but also speeded up to take nearly last half of the total time required for the five stages of flue-curing. It is therefore considered that CEPA is as effective maturity-accelerating agent and useful as known for other solanaceous plants showing climacteric stage respiration, and discussions were made about physiological actions of ethylene gas released from CEPA at plant tissues sprayed.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.103-108
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• 1981

This experiment was carried out to investigate effects of soil moisture content on the growth of tobacco plant at early stage after transplanting. Soil moisture was controlled to be 30%, 45%, 60%, 75% and 90% of the maximum water holding capacity (38.7%), and treated for 10, 20 and 30 days. Budding flowering and topping were delayed in the 30% and 45% treatment where soil moisture was deficient. Plant height, number of leaves, and length and width of the largest leaf were the best in the 75% treatment for 10 days, and development of the root and top was the best also in the same treatment. As the duration of low soil moisture treatment prolonged, intercellular space , became small. Nitrogen and potassium of the cured leaf showed the highest value in 30% and 45% treatments. Nicotine content of the cured leaf was high in the 90% treatment, and reducing sugar content of that was high in the 75% treatment for 10 days.