• Applied Biological Chemistry
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• v.15 no.1
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• pp.77-84
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• 1972

A field experiment was conducted to determine the factors responsible in limiting nutrient up take and root activity in low productive paddy fold. Radiosotope of phosphorus-32 was used as a tracer. Results of the study were as follows: 1. On yield components responsible for increase yield indicated that number of ears per panicle and ripening ratio were closely related to increase yield. 2. Root volume or root feeding area has significant influence in increasing rice yield. 3. Root volume indicative of root activity and nutrient uptake can be effected by reasonable water control. 4. The combined application of calcium, silica, and magnesium(as a fused magnesium phosphate. the Kyun-gi Chemical Co. products.) with water control, although under conditions of large amount application of nitrogen, was found to be increased the maturing rate. 5. In the plots of water control, the number of roots per one volume were less than that of the continuous flooding plots, but the weight per root was heavier than the flooding plot ones. 6. Improvement of the present native culture method could effectively increase paddy rice yield.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.2
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• pp.109-117
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• 1997

In order to hold the behavior of fish school to the set-net, a series of tag-recapture experiments were carried out in two fishing grounds of the middle sized set-nets which were located in 20m depth on the coast of Keojedo and Namhaedo in the Southern part of Korea from September to October in 1996. In the experiments, the leading ability of the leader and the fish court and the recapturing ability of the bag nets were checked out for the six species of fish in method of discharging the tagged fishes at side points of leader, and the middle points of the fish court and the bag nets in a hauling step, and recapturing them at the bag nets in the next hauling. The results obtained are as follows; 1. The ratio recaptured at the both side bag-nets in the next hauling after discharged from the fish court in the previous step was 20.3% in small size of mackerel Scomber japonicus, 16.2% in small size of horse mackerel Trachurus japonicus, 10.3% in black sea-bream Acanthopagrus schlegelii, 19.1% in red barracuda Syhyraena pinguis, 16.3% in halfbeak Hemiramphus sajori, 20.0% in gizzard shad Konosirus punctatus individually, and totally in six species of fish, that was 17.2%. 2. The ratio recaptured at the same bag net after discharged in the both side bag-nets was 21.7% in small size of mackerel, 21.5% in small size of horse mackerel, 6.7% in black sea-bream, 17.8% in red barracuda, 16.8 in half-beak, 19.1% in gizzard shad individually, and totally in six species of fish, that was 18.8%. 3. The leading ratio from side points of the leader departed from door in 25m to fish court was 58.9% in small size of mackerel, 74.6% in small size of horse mackerel, 38.0% in black sea-bream, 54.7% in red barracuda, 58.6% in half-beak, 54.5% in gizzard shad individually, and totally in six species of fish, that was 57.8%. So it was assumed that the leader of set-net was very effective in leading to the swimming direction of small size of mackerel, small size of horse mackerel, red barracuda, half-beak and gizzard shad. 4. Red barracuda, half-beak and gizzard shad entered into bag net of upstream in large numbers than bag net of downstream, and small size of horse mackerel and black sea-bream entered into bag net of downstream in large numbers than bag net of upstream. 5. Small size of mackerel and small size of horse mackerel had high remaining rate in the bag net of downstream, and black sea-bream, red barracuda and half-beak had high remaining rate in the bag net of upstream.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.249-256
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• 2016

This study was performed to investigate the effect of various concentrations of Diniconazole (DC) on the growth and quality of grafted tomato (Solanum lycopersicum) seedlings cultivated during the summer season. Concentrations of DC were set to 0 (non-treatment), 5, 10 and $20mg{\cdot}L^{-1}$, were treated once 3 days after grafting. Rootstock of the seedlings was shorter in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment compared to the non-treatment, and the scions were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment. Seedlings were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment compared with the non-treatment. Leaf area was lower for seedlings subjected to all treatments than for seedlings in non-treatment group, and reduction was dose dependent. In particular, the DC $20mg{\cdot}L^{-1}$ treatment inhibited both leaf and stem growth. The fresh weighs of leaves and stems of the seedlings treated with DC $5mg{\cdot}L^{-1}$ and the fresh weights of roots subjected to all treatments were significantly greater than those of the non-treatment seedlings. Dry weight per organs of the seedlings treated with DC $5mg{\cdot}L^{-1}$ was significantly greater that of the non-treatment seedlings, but the dry weight of leaves of seedling treated with DC $20mg{\cdot}L^{-1}$ was much less than that of the non-treatment seedlings. The T/R ratio of the seedlings was lower for all treatments than for the non-treatment. The relative growth rate of the seedlings was significantly lower in the DC $20mg{\cdot}L^{-1}$ treatment and, the leaf area rate of seedlings was lower in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment than in the non-treatment. Therefore, the optimal concentration of Dinoconazole used to produce a suitable grafted tomato seedling in the summer season is $10mg{\cdot}L^{-1}$ or less.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.420-428
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• 1996

This study was conducted to investigate the response of growth and yield of rice under five different cultural methods, machine transplanting(MTNT), puddled drill seeding (PDSNT), drill seeding on soil surface (DSNT) , broadcasting on soil surface (BSNT) under no-tillage paddy condition and conventional machine transplanting(MTT) in Jeonbuk series(siltyloam soil) from 1993 to 1995. Soil hardness was higher in no-tillage soil and increased with highly difference between tillaged and no-tillage soil with deeper soil depth. Bulk density was heavier in no-tillage soil and porosity was higher in tilled soil than that of the control. The rate of effective tiller was higher in MTT, following MTNT, PDSNT, DSNT and BSNT. Weed occurrence was more serious in no-tillage soil, than that of tillaged soil. The rate of lower internode length was lower in DSNT and BSNT and was similar with MTT in PDSNT and MTNT. Height of center gravity in terms of lodging tolerance was lower in direct seeding than in machine transplanting. Depth of buried culm was shorter in no-tillage soil, especially in DSNT and BSNT. Total amount of root was higher in MTT, following MTNT, PDSNT, BSNT and BSNT and the distribution rate of root in shallower soil layer was higher in no-tillage soil, especially in BSNT and DSNT. Field lodging occured highly in BSNT, following DSNA, PDSNT and MTNT with high lodging scale in DSNT and BSNT. Panicle number per unit land square meter was the highest in MTT and the least in BSNT. Ripened grain ratio was low in BSNT and DSNT due to heavy lodging. Yield of milled rice was 93% in PDSNT, 87% in DSNT, 81% in BSNT and 96% in MTNT, compared with 534kg /10a in MTT.