• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.92-96
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• 1987

A sweet corn hybrid. ‘Golden Elite 70’ was grown at four plant densities of 4.500, 5.500, 6,500 and 7,500 plants per 10 ares under early and ordinary season cultivations, respectively, to determine effects of plant density on growth and yield of sweet corn. Plant and ear heights and ear size were greater, and ear number per plant was less at ordinary season cultivation compared to early season cultivation. However. ear weight per 10 ares were similar between two cultural practices. There were no significant interactions between cultural practice and plant density for plant height, yield and yield components except ear length. Plant density did not affect silking date, and plant and ear heights and did not show consistent trend in ear size. Ear number per plant decreased with increasing plant density. Ear number and weight per 10 ares increased as plant density increased up to 6,500 plants per 10 ares and tended to decrease at 7,500 plants per 10 ares. The results indicate that the optimum plant density for sweet corn would be around 6,500 plants per 10 ares.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.431-435
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• 1987

Terminal bud removal has been thought as a useful practical management of soybean cultivation in Korea, and such cultivating method has been recommended till recent times. Many experiments about the effect of bud removal have been made, but it is not certain yet. This study was conducted to determine if source potential and seed yield would be affected by bud removal in 4 determinate soybean varieties. Terminal bud was removed by hand at the 5 trifoliolate stage of growth. Data were collected on leaf area and leaf dry matter weight from 58 to 101 DAP by nearly every 10 days and some agronomic characteristics and seed yield after maturity. Removing the apical bud did not increased leaf area and leaf dry matter. Number of modes and pods per a plant was increased by bud removal, but number of seeds per a pod was decreased, and seed yield was unchanged by such offsets. From the data, we concluded the source potential of soybean plants was not increased by terminal bud removal under the planting density, 22,000 pit/l0a, however it would be a useful way to reduce the lodging or over-growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.211-215
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• 1994

Lipoxygenase is involved in the formation of certain undesirable flavors of soybean products. Three isozymes(L-1, L-2 and L-3) of lipoxygenase have been identified in soybean seeds, and the three types of mutants lacking L-1, L-2 and L-3, respectively, were detected in the 1980's. In this paper, lipoxygenase activity was measured to investigate the response of lipoxygenase in organs and tissues during soybean development. There was no tendency according to genotypes between lipoxygenase lacking mutants and normal soybeans in lipoxygenase activity of leaf at $V_3$ and $V_5$ stage. Likewise, pod wall lipoxygenase was no difference among genotypes tested at R$_{6}$ stage. Seed coat lipoxygenase activity was similar among the lipoxygenase lacking mutants, while normal soybean was lower as compared with that of the lipoxygenase lacking mutants. Embryo and cotyledon lipoxygenase activity in the lipoxygenase lacking mutants was much lower than that of normal soybean, also there was large difference among lipoxygenase lacking mutants. Thus, the lipoxygenase null mutant showed very weak value although the lacking L-3 mutant had a large effect on developing embryo lipoxygenase activity. It was suggested that soybean lipoxygenase isozymes expressed in embryo may be different from those expressed in the pod wall and leaf tissues.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.431-436
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• 1994

The objective of experiment was to investigate the effects of sowing dates on forage yield and growth characteristics of rye in paddy field cultivation in midwest region of Korea. The field experiment treated with 5 levels of sowing dates was carried out at Yesan from october 1990 to june 1991. The field emergence rate and winter survival rate were decreased with delay in sowing dates by the days from sowing to emergence were took a long period of time. The crop growth rate were increased with early in sowing date. The fresh and dry weight of rye were increased with early in sowing date, but there was no significant differences between sowing date from Oct. 5 to Oct. 25. The highest fresh yield was obtained at flowering stage and the highest dry yield was obtained at milky stage. The ratio of leaf blade and leaf sheath in rye plant were decreased with earlier sowing date and delayed harvest, but the ratio of stem and inflorescence was vice versa.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.48-54
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• 1987

To search for the optimal nitrogen application method for the machine transplanting to Dongjinbyeo, compared to conventional method, in the various methods of nitrogen split application at different growth stages of rice plant. This experiment was performed at Honam Crop Experiment Station, in 1985 year. The results were as followed; the nitrogen contents of leaf blade was the highest at maximum tillering stage under the conventional method and reduction division stage under the nitrogen top-dressing at panicle initiation and 5 times split application of nitrogen for the whole rice growth stages. CGR, RGR and NAR after heading was highest under 5 times split application of nitrogen for the whole rice growth stages. Relationships between CGR and NAR, NAR and RGR, CGR and RGR showed the positive correlation significantly at each rice growth stage, respectively, and showed more high correlation according to further rice growth stages. The degree of contribution of CGR to rice grain yield was the highest at 20 days after heading. Rice grail: yield was higher under top-dressing of nitrogen at panicle initiation and basal application (30%) + 4 times equal dispensing top-dressing after basal application of nitrogen than conventional method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.411-434
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• 1982

Yield loss of wheat and barley due to meteorological constraints has been analyzed in order to get the basic information, which will lead to the counter-measures for dissemination of agricultural technology and administration. These meteorological damages were analyzed on the results of percentage yield loss and mechanism of damage and the aspects of constraints were explained. The annual yield loss of wheat and barley were 21.7% by meteorological stress: Cold damage, 5.9% ; excessive soil moisture, 5.6% ; lodging, 2.9% ; drought, 3.0% ; disease, 4.3% etc. Those damages by the stresses mentioned above and rain damage were analyzed in relation to the growth stages and the degrees of damage. The predispositions and the growth of wheat and barley to those meteorological stress are also discussed. Varietal resistances of wheat and barley to those stresses were indexed and the physiological and morphological characteristics of these resistant cultivars are described. Cultural practices to minimize the damages were also reviewed.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.73-80
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• 2000

This study was carried out to investigate the optimal mycelial growth and an artificial cultivation conditions of Pleurotus eryngii. The optimal medium for the mycelial growth and density was MYPA medium. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and 6.0, respectively. The modified optimal medium composition were obtained to be soluble starch 3%(w/v), malt extract 0.25%(w/v), yeast extract 0.25%(w/v) and $CaCl_2{\cdot}2H_2O$ 0.05% (w/v). From the results of experiment on the nutritional requirements, the modified optimal medium was higher than MYP medium in mycelial production and growth yield (Yx/s) of Pleurotus eryngii. The optimal sawdust species of solid culture for the mycelial growth and density was Quercus spp. The optimal concentration of additives (rice bran and wheat bran) and moisture content for the mycelial growth were about 30%(v/v) and 70%(v/v), respectively. On the other hand, the optimal concentration of additives for the production of fruiting body was 20%(v/v) of rice bran.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.372-376
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• 1992

This experiment was conducted to determine hay making time on the drying period, hay moisture content, hay loss content, yield and forage quality of Italian ryegrass in paddy field. Plant height increased rapidly from middle of April, and leaf weight rate were 55.6% at April 20 and 18.9% at May 30. Moisture content and loss content of hay were 17.1-20.5% and 10.2-15.0%, respectively, at drying for 4 days from May 10 to May 30. As the growth stage later, crude protein, fat and ash contents reduced, but crude fiber and NFE contents increased. Dry matter and TDN yield at the cutting of May 20 and May 30 increased to 17-18% and 5-11%, respectively, than those of April 20＋May 30.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.271-276
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• 1996

This studies were conducted to basic information on growth characteristics and root yield in progeny the derived from different bolting years and to establish optimum seed production time in Angelica gigas. Plant height of early and mid-growing stages had decreased with each year increase in bolting year, but showed no significance in late growing stage at different bolting years. Root charac­teristics including root length, root diameter and dry root weight was slightly good and it had high root/ shoot ratio in third year seed production. respectively. Bolting rate showed that first year seed 38.1%, second year seed 10.4% and third year seed 1.2%, respectively. Therefore, optimum seed production time revealed third year seed for reduce bolting rate. Root yield at different bolting years showed average 1,690kg per hectare as fresh root weight on first year seed, 2,860kg on second year and 2,940kg on third year seed, respectively. A significant positive correlation was appeared between bolting rate and plant height in mid-growing stage. On the other hard, there was highly significant negative correlation between bolting rate and root yield.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.125-128
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• 1993

This study carried out to know the growth characteristics and Co-production effect of leaf, newly developed stem and fruit by different harvest times. The dry matter yield of above growth part shown the highest at mid of July. Leaf dry matter, however, shown the highest at end of June and after that decreased drastically. The dry matter yield of newly developed stem increased gradually from early stage to harvest. Fruit set number of first branch was much higher than that of main stem and 2nd branch. The more leaf and newly developed stem harvest the less fruit yield obtained. When Co-production considered by economic yield, fruit yield with three times of leaf harvest shown the best production.