• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.67-75
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• 1974

The studies are to know how much cocoon crops is damaged by the stained leaf with nicotine produced from the tobacco field cultivated in mulching system in spring season and by residual nicotine in autumn season. Furthermore, the new knowledges are to make both industries keep up with their development. In spring season mulberry Held is located higher on the West-North of tobacco held below 20 degrees of slope and with 36 per cent of East-South wind and 18 per cent of South wind blowing from tobacco fold to the mulberry fold. In addition, silkworm larvae are fed with the mulberry leaf produced in the different plots placing by the different distances, l0m, 25m, 50m, 80m, and loom far from the tobacco Held as a control and it is also considered that narcotic larvae including the dead larvae are not observed. On the other hand, it is noted that better leaf quality and abundant growth of mulberry tree is produced from the mulberry fold closer to the tobacco field and with a low slope. 1) Maximum weight of larval body at the 5th stage is damaged by the stained leaf with the nicotine up to 25m far from the tobacco held. 2) The larvae fed with the mulberry leaf in mulberry Held up to 25m far from the tobacco fold produce small number of the fresh cocoons per 1 liter. 3) Low single cocoon weight and low cocoon shell weight are produced by the poison damaged larvae fed with the mulberry. leaf up to 25m far from the tobacco field and weight of cocoon shell is damaged higher than the single cocoon weight. It is resulted in low percentage of cocoon shell. 4) Cocoon yield including the double cocoon from 10,000 larvae is decreased by the larvae fed with the stained leaf in the mulberry fold up to 25m far from the tobacco fold and 19 per cent of cocoon yield is decreased with 2.4kg of cocoon yield in l0m plot and with 2.5kg of cocoon yield in 25m plot at the first season and at the 2nd season with 1.8kg o( cocoon yield in l0m plot and with 11.5kg of cocoon yield in 25m plot, 11 per cent and 9 per cent of cocoon yield including double cocoon from 10,000 larvae is decreased, as compared with the control, respectively. With these results, it is observed that nicotine damage is occurred to the silkworm larvae if the larvae are fed with the leaf in the mulberry Held within 25m-50m far from the tobacco field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.69-89
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• 1981

Stevia (Stevia rebaudiana Bertoni) is a perennial herb widely distributed in the mountainous area of Paraguay. It belongs to the family Compositae and contains 6 to 12 percent stevioside in the leaves. Stevioside is a glucoside having similar sweetening character to surgar and the degree of sweetness is approximately 300 times of sugar. Since Korea does not produce any sugar crops, and the synthetic sweetenings are potentially hazardous for health, it is rather urgent to develop an economical new sweetener. Consequently, the current experiments are conducted to establish cultural practices of stevia, a new sweetening herbs, introduced into Korea in 1973 and the results are summarized as followings: 1. Days from transplanting of cuttings to the flower bud formation of 6 stevia lines were similar among daylengths of 8, 10 and 12 hours, but it was much greater at daylengths of 14 or 24 hour and varietal differences were noticable. All lines were photosensitive, but a line, 77013, was the most sensitive and 77067 and Suweon 2 were less sensitive to daylength. 2. Critical daylength of all lines seemed to be approximately 12 hours. Growth of plants was severely retarded at daylengths less than 12 hours. 3. Cutting were responded to short daylength before rooting. Number of days from transplanting to flower bud formation of 40-day old cuttings in the nursery bed was 20 days and it was delayed as duration of nursery were shorter. 4. Number of days from emergence to flower bud formation was shortest at short day treatment from 20 days after emergence. It was became longer as initiation of short day treatment was earlier or later than 20 days. 5. Plant height, number of branches, and top dry weight of stevia were reduced as cutting date was delayed from March 20 to May 20. The highest yield of dry leaf was obtained at nursery duration of 40-50 days in march 20 cutting, 30-40 days in April 20 cutting, and 30 days in May 20 cutting. 6. An asymptotic relationship was observed between plant population and leaf dry weight. Yield of dry leaf increased rapidly as plant population increased from 5,000 to 10,000 plants/10a with a reduced increasing rate from 10,000 to 20,000 plants/l0a, and levelled off at the plant population higher than 20,000 plants/l0a. 7. Stevia was adaptable in Suweon, Chengju, Mokpo and Jeju and drought was one of the main factors reducing yield of dry leaf. Yield of dry leaf was reduced significantly (approximately 30%) at June 20 transplanting compared to optimum transplanting. 8. Yield of dry leaf was higher in a vinyl house compared to unprotected control at long daylength or natural daylength except at short day treatment at March 20. Higher temperature ill a vinyl house does not have benefital effects at April 20 transplanting. 9. The highest content of stevioside was noted at the upper leaves of the plant but the lowest was measured at the plant parts of 20cm above ground. Leaf dry weight and stevioside yield was mainly contributed by the plant parts of 60 to 120cm above ground but the varietal differences were also significant. 10. Delayed harvest by the time of flower bud formation increased leaf dry weight remarkably. However, there were insignificant changes of yield as harvests were made at any time after flower bud formation. Content of stevioside was highest at the time of flower bud formation and earlier or later harvest than this time was low in its content. The optimum harvesting time determined by leaf dry weight and stevioside content was the periods from flower bud formation to right before flowering that would be the period from September 10 to September 15 in Suweon area. 11. Stevioside and rebaudioside content in the leaves of Stevia varieties were ranged from 5.4% to 14.3% and 1.5% to 8.3% respectively. However, no definit relationships between stevioside and rebaudioside were observed in these particular experiments.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.2
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• pp.23-30
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• 1982

Six flue- cured cultivars of Nicotiana tabacum L., 15 possible $F_1$ hybrids and $F_2$ Populations among them, and 15 haploid Populations from Fl hybrids and haploids from Parents, were evaluated. Comparisons of the $F_1$, hybrids and $F_2$ Populations with the Parents indicated that heterosis values were small but significant for yield, plant height, days to flower, leaf length and width and total alkaloids from-6.0% to 5.4% in $F_1$ hybrids, and from -3.4% to 3.6% for Plant height days to flower leaves per plant in $F_2$ populations, respectively. There were positive correlations for yield, plant height, days to flower, leaves per plant and total alkaloids between diploid and haploid populations. Increase or decrease ratio of haploids to diploids of total alkaloids was appeared to 30.3%. Those for yield, leaf length and width, value arid reducing sugar were ranged from -4.1% to -27.6%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.184-187
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• 2004

In case of a semi-forcing culture for vegetable perilla, the following research results on the effect of black polyethylene mulching, the optimum sowing season, and the seedling stand improvement method were drawn. Soil temperature was higher and the emergence was faster in a black polyethylene mulching culture than in a non-mulching culture. However, the mature was late, the main stem were larger, and the seed yield, as well as the leaf yield, was greater in a mulching culture than in a non-mulching culture. Considering growth and chilling injury, the stable sowing season of vegetable perilla was judged to be the early in January. The covering materials for improvement of the seedling stand can be a non-woven fabric and hyaline polyethylene. However, the non-woven fabric seemed to be quite suitable in view of the stability and convenience of control after the emergence of perilla.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.335-342
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• 1994

This study was undertaken at Gowa, South Sulawesi, Indonesia, as part of a larger forage genetic resource evaluation project. The experimental program consisted of a field experiment where grass and legume species were grown in monocultures and the dry matter yield, rumen bag digestibility (RBDMD) and N content of leaf and stem components were monitored in the wet and dry seasons. Eight species of grass (Brachiaria decwnbens cv. Basilisk. Panicum maximum cv. Riversdale, Urochloa pullulans CPI 41192, Imperata cylindrica from Maiwa, South Sulawesi, Digitaria milanjiana CPI 41193, Cenchrus ciliaris cv. Malopo, Heteropogon contorlus and Setaria sphacelata cv. Splenda) were studied. P. maximum was the highest yielding grass in the wet season and B. decumbens in the dry season. The highest RBDMD in the whole plants were U. pulluians, P. maximum, S. sphacelata and D. milanjiana after 2 weeks regrowth in cycle I and S. sphacelata, B. decumbens, D. milanjiana and C. ciliaris in cycle 2. When total digestible DM was calculated for the whole of cycle I, P. maximum, B. decumbens and S. sphacelata were superior, but B. decumbens produced over twice as much as the other species in the dry season (cycle 2). The leaf N concentration of all grasses exceeded 1.0% (6.25% crude protein) in the regrowth in cycle I but did not exceed 0.5% in the dry season regrowth (cycle 2).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.14-18
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• 2010

This study was conducted to investigate the effect of high-temperature during the reproductive growth period on the soybean growth and yield. Two soybean cultivars, Hwangkeumkong (HKK) and Pungsannamulkong (PSNK) were used in this study. By high-temperature treatment, plant height was increased in the two soybean cultivars, however, leaf area and dry weight were greatly reduced. Number of pod per plant was not changed by high-temperature treatment. However, number of seeds and 100 seed weight were reduced in two soybean cultivars. As compared with control, yield were decreased by 45% in both HKK and PSNK. It was also appeared that nitrogen contents in leaf, stem, and root of the HKK and PSNK were decreased by high-temperature treatment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.93-95
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• 2001

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.270-276
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• 1997

This experiment was conducted to develop a practical method to growth in hydroponics conditions. For this purpose, leaf lettuce (Lactuca sativa L., cv. 'Cheongchima') was cultivated under different temperature and light conditions in experimental fields of Sahmyook university from March, 1991 to May, 1996. The visual quality score(VQS), a quantitative parameter to evaluate harvested leaf lettuce quality. The leaf lettuce cultivated at $25^{\circ}C$ solution temperature showed the highest fresh weight pe, plant (59.7g/plant), but lowest visual quality score (5.2), while leaf lettuce cultivated at 15$^{\circ}C$ solution temperature showed lower fresh weight per plant (25.2g/plant) but highest visual quality score (7.2). In general, growth of leaf lettuce was retarded by low solution temperature, but quality was higher than those of other solution temperature. Different day/night temperature of nutrient solutions 20/2$0^{\circ}C$ and 25/2$0^{\circ}C$ was highest in yield, but leaf type was grow longer, and visual quality are inferior to low temperature. Yield was decreased as 10 and 25% at 60 and 80% shading treatment, respectively. Chlorophyll content was decreased by shading. but plant height and root length were increased of leaf lettuce growth with hydroponics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.40-47
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• 1987

Under the different conditions of planting density and compound fertilizer level, some agronomic and chemical characteristics of burley tobacco were investigated from 1982 to 1984. Leaf area and dry leaf weight per plant, crop growth rate, relative growth rate and net assimilation rate for 40-60 days after transplanting were higher with increasing plant spacing and fertilizer, but leaf area index was lower with increasing plant spacing. At topping stage, the leaf size was increased with increasing plant spacing and amount of fertilizer applied and the stem diameter was increased by increasing plant spacing. Leaf area, leaf weight per plant and weight per unit leaf area of harvested leaf were higher when plant spacing and fertilizer increased. It was estimated that the optimum plant spacing was 105cm x 34cm and level of com-pound fertilizer (N-P$_2$ O$\sub$5/ -K$_2$O =10-10-20) was 263kg/l0a for high yield. There were trends toward increase the contents of total alkaloid and total nitrogen with increasing plant spacing and fertilizer application. There was significant positive correlation between plant spacing and total nitrogen, and between fertilizer application and total nitrogen. The plant spacing of 105cm x 35 to 40cm and 227.5kg/l0a of fertilizer level may be profitable for farm economy and the low nitrogenous leaf.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.799-807
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• 2004

The objective of this field experiment was to investigate the growth, hay yield and chemical composition of cassava and stylo 184 grown under intercropping. The experiment was arranged in a Randomized Complete Block (RCB) design with 5 treatments and 4 replications. The treatments were: sole crop cassava (C); sole crop stylo 184 (S) and three intercropping treatments comprising an additive series of one (SC), two (SSC) and three (SSSC) rows of stylo 184 to one row of cassava. The results showed that leaf area per plant (LA) of cassava was significantly higher (p<0.05) in the sole crop relative to the intercropping treatments. Both total hay yield and CPDM yield were significantly higher (p<0.05) for C treatment and lower (p<0.05) for SSSC treatment. The total hay yield and CPDM yield were significantly greater (p<0.05) in the sole crop relative to the intercropping treatments. At the first and second harvests, CP content was similar among treatments; while at third and fourth harvests, CP contents were significantly greater (p<0.05) for the intercropping treatment relative to the sole crop. At the first and second harvest, NDF contents were significantly greater (p<0.05) in the sole crop relative to the intercropping treatments, whereas NDF contents were similar among intercropping treatments. Leaf area of stylo 184 at first and second harvest were significantly greater (p<0.05) for C, SC and SSC as compared with the SSSC treatments. At each harvesting, there were no significant differences in ash, CP, NDF, ADF and ADL contents of stylo 184 hay between the sole crop and intercropping treatments, except for the first harvest. ADF contents were significantly greater (p<0.05) in S, SC treatments relative to SSC and SSSC treatments. Both collective hay yield and CPDM yield of cassava and stylo 184 were significantly greater (p<0.05) for the SSC treatment and significantly lower (p<0.05) for the S treatment. Collective hay yield and CPDM yield were significantly greater (p<0.05) for the intercropping treatments relative to the sole crop. Based on this research, it was concluded that stylo 184 showed potential for intercropping with cassava. Intercropping cassava with stylo 184 has beneficial effects and can improve foliage biomass yield and soil fertility, which would be a more sustainable system than growing the cassava as a pure stand. In terms of hay yield and CP production, two rows of stylo 184 to one row of cassava could be the optimal pattern for this intercropping system.