• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.63 no.4
• /
• pp.294-303
• /
• 2018

To set an optimal harvest time for five main whole-crop silage (WCS) rice cultivars, Nokyang (Ny), Mogwoo (Mw), Mogyang (My), Nokwoo (Nw) and Yeongwoo(Yw), based on feed value and dry matter yield, we analyzed water content (WC), feed values such as percent crude protein (CP), crude fat (CF), crude ash (CA), neutral detergent fiber (NDF), acid detergent fiber (ADF), estimated total digestible nutrients (TDN), and calculated their dry matter yield (DMY). These parameters were estimated at the booting stage and every 10 days from start of heading to 45 days after heading (DAH) to identify the optimal harvest time for these rice varieties. In all varieties, except Ny, the WC was about 65% on the $30^{th}$ DAH. In terms of WC, it is judged that there would be no major problem in preparing high quality silage when harvested between 20~30 DAH for Ny and about 30 days for the other cultivars. The CP and CA decreased significantly as the harvest time was delayed in all varieties (p<0.05). However, the CF in the tested varieties generally declined as DAH increased, and then increased again(p<0.05). The decrease in ADF and NDF was significantly different from the booting stage to 45 DAH in all varieties (p<0.05) and the estimated TDN increased gradually in all varieties as the harvest time was delayed. The TDN of all varieties, except Nw, was over 70% around 30 DAH. As harvest time was delayed, the DMY for all WCS rice increased significantly (p<0.05). The maximum DMY for each cultivar was observed at 45 DAH, however, no significant difference (p<0.05) was seen after 40 DAH for Ny and Yw, 30 DAH for Mw and Nw, and 20 DAH for My. Considering these results and others factors such as lodging, shattering, digestibility of grains, conversion of eating rice, etc., the optimal harvest time for silage use of all WCS rice tested was generally the yellow ripening stage, at about 30 DAH (30~40 DAH for Ny and Mw, and 30 DAH for My, Nw and Yw).

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.504-510
• /
• 2016

This study was investigated to find the effects of sowing time on growth and yields of cowpea grown in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (Latitude 35° 04' N, Longitude 126° 54' E) during 2013 and 2014. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2 (Okdang). Sowing time was performed between middle-April and middle-August at intervals of one month. The days from sowing to emergence was significantly higher in the middle-April sowing (12 days) time but there was no significant differences other sowing dates (5 to 3 days). The days from sowing to first flowering were shorter for sowing dates between middle-April and middle-July because sowing time was delayed and then were lengthened again at middle-August sowing; the days were longest at middle-April sowing (around 62 days) and were shortest at middle-July sowing (35 days). The days from first flowering to harvesting were short for the sowing dates between middle-April and middle-July (17 to 15 days) but were relatively long for middle-August sowing date (24 days). Stem length was relatively long for the middle-May and middle-June sowing dates. Peduncle length was relatively long for the middle-April sowing date. Main-stem node number was highest for the middle-July sowing. Branch number per plant was highest in the middle-April sowing. Seed yields were highest for the middle-April sown Jeonnam1 and the Jeonnam2 (Okdang) strains showing, 199 and 211 kg/10a, respectively, and then followed by sowing in middle-July, 191 and 195 kg/10a, respectively.

• Korean Journal Plant Pathology
• /
• v.2 no.3
• /
• pp.193-198
• /
• 1986

Bottom rot of Chinese cabbage (Brassica pekinensis Rupr) hitherto undescribed in Korea is caused by Rhizoctonia solani Kuhn. Development of bottom rot in fall crops was observed and the efficiencies of fungiciial control in naturally infested field in Southern region were studied. Bottom rot symptom started to develop 20 days after transplanting 20 day old seedlings, which corresponded to the middle growing stage. At the reading stage, the infection rate increased substantially, which progressed upto an average of $52\%$ at harvesting time. The overall infection rate was about $30\%$ in Chinese cabbage field under plastic film house cultivation. However, disease intensity of fall crops was less severe than that of crops in plastic film house. where plants infested earlier, stunted and their growth was extremely poor. Optimum temperature for mycelial growth of bottom rot isolates of R. solani was $20\~25^{\circ}C$ on potato-sucrose agar. This fungus was highly pathogenic on seedlings of Chinese cabbage, radish, sesame and rape resulting in high percentage of damping-off. For other crops, such as lettuce, tomato the cucumber, the germination was delayed for 2-3 days and the percentage damping-off was lower. Anastomosis group of this fungus was idenlfied as AG II-I. Soil drenching of fungicide pencycr WP., three applications at 10 day interval, was effective; indicating the most promising one with control value $80\%$.

• Journal of Mushroom
• /
• v.15 no.4
• /
• pp.269-272
• /
• 2017

We developed a log-burying cultivation technique for Grifola frondosa using oak logs and surveyed its annual yield characteristics. As a result of G. frondosa log cultivation, the harvesting period of the 'Yipsae1ho' cultivar was delayed by approximately 10-15 days compared to that of the Dabak cultivar, and the fruit color of the 'Yipsae1ho' cultivar was dark brown, while that of the 'Dabak' cultivar was grayish brown. Yield of the 'Yipsae1ho' cultivar was $16.0 kg/m^2$ in the first year, $15.4kg/m^2$ in the second year, $9.5 kg/m^2$ in the third year, $4.6 kg/m^2$ in the fourth year, and $4.6kg/m^2$ in the fifth year, while yield of the 'Dabak' cultivar was $12.3kg/m^2$ in the first year, $11.5kg/m^2$ in the second year, $12.7kg/m^2$ in the third year, $6.2 kg/m^2$ in the fourth year, and $8.2kg/m^2$ in the fifth year. Total yield of the 'Yipsae1ho' cultivar ($50.0 kg/m^2$) was slightly lower than that of the 'Dabak' cultivar ($50.8kg/m^2$). The optimum period for log-burying cultivation of Grifola frondosa is estimated to be 3 years.

• Korean Journal of Plant Resources
• /
• v.31 no.1
• /
• pp.71-76
• /
• 2018

This study was conducted to investigate the effect of shoot twist on fruitfulness and fruit quality of 'Campbell Early' grapevine. Proper pruning and training are essential to produce a good yield of high-quality fruit and to maintain the balance between vegetative growth and fruiting. The most common problem in spur-pruned 'Campbell Early' cultivar is that vigorous buds has low fruitfulness and thereby the shoot become more vigorous the following spring because of lower crop load. Therefore, shoot twists in very vigorous 'Campbell Early' canes (above 10.0 mm) were performed on the third nodes and the $7^{th}$ nodes of each shoot at 7 days before bloom and full bloom, respectively. Sprouting date, blooming date were not significantly different among the treatments while, harvesting date was delayed approximately 3 days. However, number of berries per cluster, cluster weight and fruitfulness were significantly higher in the shoot twist treatment on the third nodes than the control that was topping alone. Combination treatments of shoot twist and topping had an additive effect on increasing cluster weight resulting in higher increase of yield by 12.1 ㎏ per vine. These results indicated that the shoot twist on very vigorous canes of 'Campbell Early' grapevine for well fruitfulness seemed to be very effective.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.6
• /
• pp.557-564
• /
• 2000

The bone graft materials can be grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Much care was given to other bone graft materials away from autogenous bone due to its additional operation for harvesting, delayed resorption and limitation of quantity. Demineralized freeze-dried bone(DFDB) and hydroxyapatite are the representatives of bone graft materials. As resorbable hydroxyapatite is developed in these days, the disadvantage of nonresorbability can be overcome. So we planned to study on the strength and the bone formation at the rats calvarial defects of DFDB graft and those of the composite graft with DFDB and resorbable hydroxyapatite. We used the 16 male rats weighting range from 250 to 300 gram bred under the same environment during same period. After we made the 6mm diameter calvarial defect, we filled the DFDB in 8 rats and DFDB and resorbable hydroxyapatite in another 8 rats. We sacrificed them at the postoperative 1 month and 2 months with the periostium observed. As soon as the specimens were delivered, we measured the compressive forces to break the normal calvarial area and the newly formed bone in calvarial defect area using Instron(Model Autograph $S-2000^{(R)}$, Shimadzu, Japan). The rest of the specimens were stained with H&E(Hematoxylin & Eosin) and evaluated with the light microscope. So we got the following results. 1. In every rats, there was no significant difference between the measured forces of normal bone area and those of the bone graft area. 2. In 1 month, the measured forces at DFDB graft group were higher than those of the DFDB and resorbable hydroxyapatite composite graft group(P<0.05). 3. In 2 months, there was no significant differences between the measured forces of DFDB graft group and those of the DFDB and resorbable hydroxyapatite composite graft group. 4. In lightmicroscopic examination, most of the grafted DFDB were transformed into bone in 1 month and a large numbers of hydroxyapatite crystal were observed in DFDB and resorbable hydroxyapatite composite graft group in 1 month. 5. Both group showed no inflammatory reaction in 1 month. And hydroxyapatite crystals had a tight junction without soft tissue invagination when consolidated with newly formed bone. 6. In both groups, newly formed bone showed the partial bone remodeling and the lamellar bone structures and some of reversal lines were observed in 2 months. From the above results, it is suggested that DFDB and resorbable hydroxyapatite composite graft group had a better resistance to compressive force in early stage than DFDB graft group, but there would be no significant difference between two groups after some period. And it is suggested that the early stage of bone formation procedure of DFDB and resorbable hydroxyapatite composite graft group was slight slower than that of DFDB graft group, but there would be no significant difference between two groups after some period.

• Horticultural Science & Technology
• /
• v.32 no.4
• /
• pp.440-447
• /
• 2014

For this analysis, canopies of slender-spindle 'Hongro'/M9 apple trees were divided into 4 positions: upper, lower, exterior, and interior parts. The photosynthetic rate was highest in the external part of the upper canopy of the tree, where it was 4.5 times higher than in the internal part of the lower canopy. This difference was closely associated with differences in light penetration based on canopy position. Analysis of leaf growth characteristics showed that the leaves situated in the internal part of the canopy were larger and thinner than those in the external part of the canopy. The difference in leaf thickness was mainly due to thickness of the primary layer of palisade tissues (68.5 and $110.3{\mu}m$ for internal and external leaves, respectively). Fruit weight and quality were closely related to the extent of light penetration. Fruit weight, soluble solid content, and red skin color were higher in the fruits from the external part of the canopy. Thus, fruit maturity was delayed in the internal part of canopy. The fruit skin and wax layer were thicker in fruits from the internal canopy than in those from the external canopy. Therefore, our results indicate a need for improved light penetration in internal parts of the canopy and for split harvesting depending on maturity at different canopy positions.

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.3
• /
• pp.248-253
• /
• 2018

Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, $NO_3$, $P_2O_5$, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.2
• /
• pp.126-133
• /
• 1988

To know the optimum harvest time for seed yield and seed quality a local variety of rye 'Paldang-homil'was harvested at seven different harvest times from 25 to 55 day after heading (DAH) at five-day intervals in 1984 ani 1986. Seed development, seed germination and seedling growth were observed. The l000-grain weight increased as harvest time delayed until 50 DAH in both years. Although grain yield tended to increase with delay of harvest time, the yield differences between succeding harvest time was highest between 40 DAH and 45 DAH. Germination rate of seeds harvested before 30 DAH were lower than those after 35 DAH at 20 C, but at 10 and 30 C before 35 DAH were lower after 40 DAH. Plant height and dry weight of seedlings increased with delay of harvest time up to 45 DAH in pot. Heading stages were similar among the seeds harvested 40-55 DAH. Culm length was not different among the harvest times. The optimum harvest time for seed production of rye seems to be 45 DAH (38 days after flowering).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.35 no.3
• /
• pp.273-281
• /
• 1990

Two rice varieties, Samkangbyeo and Sangpungbyeo, were transplanted on 1/2000a pots at 6 different dates beginning on May 11 with 10 day interval in 1987 and at 4 different dates beginning on May 21 with 10 day interval in a paddy field at the Chungbuk Provincial Rural Development Administration. Dry matter distributions to stem and leaf sheath, leaves and ear at different growth stages were analyzed to provide basic informations neccessary for the development of dynamic growth model. Dry matter production was reduced as transplanting was delayed and the degree of reduction was greater at the transplanting later than June 1. Dry matter distribution to stem and leaf sheath was increased up to 60-70 days after transplanting with the maximum ratio between 60-70%, which were decreased to 37-43% in pots and 27-33% in field at the end of ripening stage. On the other hand, dry matter distribution to leaf blade was decreased from 40-50% at transplanting to 11-17% at harvesting. Ear dry matter distribution increased rapidly after heading and the distribution ratio was 42-49% in pots and 52-62% in field. Although regression equations to predict dry matter distribution to different parts of rice plant were satisfactory for individual experiment, the application to different experiment was not appropriate.