• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.25 no.4
• /
• pp.81-85
• /
• 1980

Field experiment was conducted to determine the optimum harvesting time in winter rape (Brassica napus L.) by investigating the percent oil, 1, 000 seed weight, seed yield, dehiscent pod ratio and oil yield at 46, 50, 54, 58, 62, 66 and 70 days after flowering. Variation of all characters with days after flowering could be explained significantly by second degree polynomial equations. Percent oil and 1, 000 seed weight increased until 62 days after flowering and thereafter these traits decreased, while seed yield increased to 58 days after flowering and thereafter this trait decreased. This controversy was due to the drastic increase in dehiscent pods beyond 58 days after flowering which brought loss in seed yield. These results suggest that optimum harvesting time is 58 days after flowering and it should not be later than 60 days after flowering.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.4
• /
• pp.347-354
• /
• 1992

Late harvest in peanut has often resulted in reduced yield and dissipation of labor by virtue of increasing over-matured pods causing the pod shattering. Present study was conducted to obtain a basic information for deciding optimum harvest time of the peanut in Chungbuk province by examination of yield components at different harvest time of leading cultivars Saedl and Youngho cultivated with vinyl mulching or non-mulching conditions. Peg number and pod number were significantly increased by vinyl mulching and also significantly different by the harvest time. Pod number increased with the lapse of days after flowering was gradually decreased from 100 days after flowering in saedl and 110 days in Youngho. Number of seed-bearing pods and matured seed percent were significantly increased by vinyl mulching and had tendency to increase with the lapse of days after flowering. There was no significant difference in number of over-matured pods and pod shattering percent between vinyl mulching and non-mulching. They increased drastically in 110 days after flowering in Saedl, but in 120 days after flowering in Youngho, Increase in 100 seed weight by vinyl mulching was statistically nonsignificant in both varieties, however, total seed yield was significantly increased by vinyl mulching, showing maximum yield in 100 days after flowering in the variety Saedl and 110 days in Youngho, respectively, Seed yield was negatively correlated to peg number and positively correlated to pod number, seed-bearing pod number, pod shattering percent, matured seed percent and 100 seed weight, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.2
• /
• pp.93-96
• /
• 2000

The present study was performed to obtain the basic information about growth and quality related characteristics and optimum harvesting time for podedible pea which is a new crop in Korea but believed to have a great deal of potentials for both domestic and overseas markets. They can be consumed either as a fresh succulent vegetable or as tender green pods. The daily green pod yield of pod-edible peas started to increase from ten days after flowering and the maximum yield was recorded on 26 days after flowering. Ninety percent of pod yields could be harvested from 16 to 36 days after flowering. Mean green pod yield for the tested varieties was approximately 8.0 t/ha. Total vitamin C content of pod-edible peas showed continuously decreasing trends from five days after flowering. The highest sucrose content was obtained at ten days after flowering. The highest panel score based on sweetness, chewiness, and hardness for the processed green pods was shown at 10-15 days after flowering in all varieties tested, indicating that the optimum harvesting time for pod-edible peas was considered to be 10-15 days after flowering.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.3
• /
• pp.221-224
• /
• 1999

A field experiment was carried out to observe the weed control effects of vetch and to evaluate vetch characteristics on clay loam soil in no-till direct-sown rice-vetch cropping systems. The effects of weed control, forage productivity, and N content of vetch plants were investigated. With the progress of plant growth, density of Chinese milk vetch (Astragalus sinicus L.) gradually decreased, but densities of foxtail and other weeds decreased steeply due to the depression by the over-shaded vetch canopy in a no-till direct-sown rice-vetch cropping paddy field. The vetch density in tillage systems was lower than in notillage cropping systems. Lower vetch density occurred with an increase in foxtail density and other weeds. Weed control effect increased by the progress of vetch growth, which indicated that the vetch canopy over-shaded the weeds. Vetch straw was degraded rapidly submergence after with water at the time of wet sowing of rice. Early harvesting of vetch seed resulted in lower seed germination. To acquire enough seedlings without re-sowing, the harvesting of seed should be delayed at least 28 days after the flowering stage in order to ensure the vetch population is sustainable in a no-till direct-sown rice-vetch cropping system. In order to improve the survival of vetch plants, vetch seeds should germinate from the heading .stage to before the full-ripening stage of rice plants. To enhance the percent of over-wintering survival, vetch seeds should germinate no later than the end of October in southern Korea. The dry weight of vetch plants increased with the progress of vetch growth until the flowering stage but N content decreased for 30 days from before the flowering stage (2.9%) until the ripening stage (1.8%). We concluded that Chinese milk vetch could have an effect on weed control before the flowering stage, sustainability without re-sowing of seed annually, and effective green manure for rice pre-crop in no-till direct-sown rice-vetch relay cropping systems.

• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.1
• /
• pp.7-11
• /
• 1999

This experiment was conducted to investigate the effects of soil conditioners, such as lime, borax, poultry waste sawdust manure (P.W.S.M) and mixed oil cakes (M.O.C), on the rutin biosynthesis and the yield of buckwheat. The content of phosphorus ($P_2O_5$) in buckwheat plants before flowering was higher at before flowering than that of flowering time at all plots. The content of nitrogen (N), potassium ($K_2O$), calcium (CaO) and magnesium (MgO) was lower at before flowering than those of flowering time at all plots. The contents of rutin in buckwheat plant at flowering time was higher than that at before flowering content of rutin in leaf was higher than that in stem. The contents of rutin in buckwheat plant was the highest at the plot treated with borax (B) compared to other plots. Correlation between rutin and amino acid was positive in buckwheat leaf, while it was negative in buckwheat stem. The yield of buckwheat was 21 percent higher at the plot treated with borax than the plot applied with the other three ingredients.

• Horticultural Science & Technology
• /
• v.30 no.3
• /
• pp.236-242
• /
• 2012

We investigated the influences of night interruption (NI) and night temperature on flowering and flower coloration in Cymbidium. Cymbidium 'Red Fire' and 'Yokihi' were grown under a 9 hours photoperiod (control), a 9 hours photoperiod with NI at a low light intensity (LNI) of 3-7 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, or a 9 hours photoperiod with NI at a high light intensity (HNI) of 120 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for four hours (22:00-02:00 HR) for 16 weeks during the reproductive growth stage (Experiment 1). Thirty month-old Cymbidium 'Red Fire' plants with initiated flowering buds were placed in four different growth chamber with night temperature set points of 6, 9, 12, or $15^{\circ}C$ for 16 hours (18:00 to 09:00 HR) and a daytime temperature of $25^{\circ}C$ (Experiment 2). In Experiment 1, the numbers of visible buds and flowers increased, and time to flowering decreased in both the LNI and HNI treatments, as compared to the control in both cultivars. Red color in Cymbidium 'Red Fire' increased by both LNI and HNI, as evidenced by an increased $a^*$ in plants grown under these conditions, relative to those grown under the control condition. Number of days to visible buds at 9-$15^{\circ}C$ ranged from 31-34 days, as compared to 39 days at $6^{\circ}C$ in Experiment 2. Although as the temperature increased days to flowering decreased when the plant was grown at $15^{\circ}C$ as compared to 6, 9, or $12^{\circ}C$, the red color ($a^*$) also decreased. The number of flowers and percent flowering increased when the night temperature was maintained higher than $9^{\circ}C$. Therefore, NI treatment and maintaining the night temperature at approximately 9-$12^{\circ}C$ during the winter season after flower spike initiation in the reproductive developmental growth stage improve flower quality and controls flowering time.

• Korean Journal of Medicinal Crop Science
• /
• v.9 no.3
• /
• pp.186-191
• /
• 2001

This study was conducted to find the flowering and seed setting characteristics of Eleutherococcus spp. Plants of Eleutherococcus spp. were 7 years old trees reproducted by cutting method using seven species in Gongju. Initial flowering date was foremost by May 9 in E. sieboldianus and hindmost by August 23 in E. divaricatus among seven species. Flowering duration was most short by 20 days in E. sieboldianus and extremely long by 42 days in E. sieboldianus. Number of flowers per plant in E. sieboldianus and E. chilsanensis were higher by 4677 and 4634 than those in E. divaricatus and E. sieboldianus by 780, 84, respectively. The fruit setting percent was the highest in E. sieboldianus by 95% and numbers of fruit setting per cluster showed the highest value by 153 in E. sieboldianus. The seed setting percent was almost same by ${92{\sim}95%}$ in E. sessiliflorus, E. chiisanensis, E. koreanus, E. divaricatus and E. seoulensis, but lower by ${11{\sim}37%}$ in E. senticosus and E. sieboldianus. The dry weight per plant and 100-fruit weight showed the highest value by 270g, 6.7g in E. sessiliflorus, respectively.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.28 no.1
• /
• pp.48-53
• /
• 2000

This study was carried out to investigate the growth characteristics and propagation methods of Prunus species as woody landscape plants. Both the flowering time and the survival rate of grafting were investigated. The results are obtained as follows: The total of flowering period of Prunus species in Kyonggi province area lasted for about 26 days. The flowering time of the species overlaps. These observations suggest that the possibility of interspecific pollination among Prunus species is very high in the kyonggi province area. The total number of flowers in the species in area was in as follows decreasing order : (1) Prunus yedoensis >Prunus pendula var. ascendens > Prunus subhitella > Prunus sesrulata for. fugenzo > Prunus leveillenana var. pendula. The number of carpels in each flower ranged from 0.3 for Prunus subhirtella to 1.8 for Prunus serulata for. fugenzo. In the caseof Prunus sesrulata for. fugenzo, the carpels appeared to be degenerated and thus losted their function. However, there exist two tyoes of Prunus subhirtella. While one type had normal carpel, the other had the degenerated one. The survival rate of grafting was investigated on May 19. Eighty there percent of the plants survived when the grafting was made in the greenhouse in January whereas the plants grafted in nursery in March survived less in that Prunus suhirtella showed 64%, Prunus leveilleana var. pendula 47%, Prunus sesrulata for. fugenzo 43%, Prunus yedoensis 62% and Prunus pendula var. ascendens 24%, respectively. Therefore, it suggested that high humidity and optimal temperature appeared to incase the survival rate of the grated plants. We therefore propose here that grafting should be done in the greenhouse that both humidity and temperature could be controlled to enhance the efficiency of grafting. This will enable as to perform grafting in winter as well.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.2
• /
• pp.113-122
• /
• 1998

This experiment was conducted to establish the cultural method of triticale(Triticum Secalotriticum Saratoviense Meister) as a whole crop silage by evaluating the effect of seeding date and nitrogen fertilization rate on forage yields and feeding value. Heading date, flowering date, and the dough stage of development came significantly earlier as triticale was seeded earlier. Soilage, dry matter yields and percent dry matter significantly varied with seeding dates and crude ash, NFE and TDN. However, TDN yield was significantly reduced by delayed seeding. Macromineral contents were not affected by seeding date. Soilage, dry matter yield, and percent dry matter significantly increased as nitrogen fertilization rate increased. The contents of crude protein, crude fat, crude ash, NFE, TDN and TDN yield also significantly increased. In contrast, crude fiber content of triticale decreased with increasing N fertilization rate.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.17
• /
• pp.45-78
• /
• 1974

To provide useful information for developing new high yielding soybean varieties and for improving cultural practices, an investigation was made on variation of dry matter production and on relationship among several agronomic characters of soybean plants grown under different planting times and densities as well as under different fertilizer levels, using Kwang-kyo, Dong puk-tae, and Suke ＃ 51 as determinate types and Shelby, SRF-300 and Harosoy as indeterminate types at the Crop Experiment Station during the period of 1972 and 1973. The results obtained were summarized as follow: 1. The dry weight, CGR and LAI at the initial flowering stage were high in the high plant population irrespective of varieties, planting times, and fertilizer levels. However, those characters of the indeterminate type were lower than those of the determinate types. The same characters of the indererminate type at the terminal leaf stage were either same or higher than those of the determinate types. 2. The dry weight of the determinate type at the initial flowering stage was similar to the indeterminate, type, when planting times were May 21 or June 15. The dry weights of both types of varieties were low when planted on July 10. When fertilizer levels were increased, the CGR, dry weight and LAI at the initial flowering stages were also increased. 3. Even though significant differences of LAI were obtained among the varieties within the same plant type, the indeterminate type was in general lower than that of the determinate type regardless of planting time and densities, or fertilizer levels, while the yield of the indeterminate type was comparable to the yield of the determinate type. 4. The high degree of leaf- and petiole-fall at the greenbean stage was highly associated with early planting and high levels of fertilizers. However, less amount of leaf- or petiole-fall was found when planted on July 10 or under low plant population. 5. The percent of stem weight was high under higher plant population, while the percent of leaf weight was high under lower plant population. When planting time was late, the percent of stem and petiole weight were reduced, while the leaf weight was increased. 6. The percent of pod weight of the determinate type at the terminal leaf stage was about 2% when planted on May 21, about 8% when planted on June 15, and about 9% when planted on July 10. The percent of pod weight of the indeterminate type at the terminal leaf stage were about 6 % when planted on May 21, 14% when planted on June 15 and 21% when planted on July 10. 7. Kwang kyo showed less degree of leaf-fall even when lodged due to high levels of fertilizer applied, while SRF-300 showed great damage due to lodging. 8. High yields were obtained when planted on May 21, but there were little yield differences between yields from May 21 and June 15 plantings. The reduction of yield due to late planting of July 10 was less apparent in the determinate type of varieties, while it was high in the indeterminate type. 9. The optimum plant population per are for high yield was 1, 250 to 2, 500 plants when planted on May 21, 2, 500 plants when planted on June 15, and 3, 333 plants when planted on July 10. 10. High correlation coefficients were obtained between dry matter weight and LAI at the terminal leaf stages, and between the dry matter weight and yield at the greenbean stages. The optimum dry weight for high yield in the determinate type was expected to be 25 kg. per are at the initial flowering stage and 50 kg. per are at the terminal leaf stage. In the indeterminate type the LAI and dry weight at the greenbean stage were 4 to 5 and 80 kg. per are, respectively. 11. Under the high plant population plant height was increased, while the stem diameter and the number of nodes and branches were reduced. Consequently, the percent of mainstem to main stem plus branches were increased, and the length of internode was also elongated. The ratios of stem weight, number of nodes and pods, and yield of main stem were increased when high plant population was associated with the early planting. The percent of main stem to branches for the indeterminate type was higher than that of the determinate type. 12. Under the high plant densities and late planting, the percent of the pod number and yields of main stem were increased, indicating that varieties with no or less branches were better adaptable under such conditions. 13. High degree of simple correlation coefficients was obtained between the LAI at the initial flowering stage and terminal leaf stage, and the total node number, dry matter and dry stem weight of both determinate and indeterminate types. Even though no significant correlation was found between the LAI at the initial flowering stage of the determinate type and the stem length and pod number per are, highly significant correlation coefficients were obtained between such characters in the indeterminate type of varieties. 14. The dry matter was positively correlated with the LAI, CGR, stem length, and pod number, node number and dry stem weight per are, while no significant correlation was found between the dry matter and stem diameter. 15. The correlation coefficients between lodging index and the LAI, dry weight, stem length and dry stem weight were highly significant. Negative correlation was obtained for the indeterminate type between the stem diameter and lodging index. The correlation coefficient between the stem diameter and lodging index was non-significant for the determinate type, while positive correlation was obtained between the yield and lodging index in the determinate type. The lodging index was also positively correlated with average length of internode of main stem. 16. The 100 seed weight appeared to be lowered under the high plant population and no fertilizer condition, and when planted late. Apparent differences of 100 seed weight were found between main stem and branches, being higher for the main stem than for the branches. 17. No variation of protein content was found due to different cultural practices. However, the oil content was apparently reduced when planted late.