• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.2
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• pp.147-151
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• 1983

In order to know the effect of planting date and cutting management on Jerusalem Artichoke (Helianthus truberosus L.) as a new forage or energy crop, JA tubes were planted from April 7 to June 27 with 20 day interval. Growth and yield could stay high as normal planting if tuber planting had been done until late May. The delayed planting after June caused deterioration of seed tuber, produced poor emergence and retarded growth. Previous harvested field did not need additional planting every spring because there were enough leftover tubers usually small size, less than 3gr., to provide a dense seedling establishment. This plot had too dense in population to adjust its spacing by thinning some of seedlings. One or two times cutting for forage or silage production reduced tuber yield very significantly. Therefore, it was not a good management to harvest for both forage and tuber production. Topping at 20cm from growing point in early July prevented from lodging and assured tuber yield.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.712-721
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• 2015

To improve the breeding efficiency of oriental pear, heritability, correlation and frequency distribution of fruit ripening date were analyzed using 4,035 seedlings obtained from 15 families between 13 parental cultivars. Although variation of fruit ripening time was higher in most early-ripening parental cultivars than in late-ripening parental cultivars, according to analysis of average, standard deviation, and coefficient of ripening variation for ten years, fruit ripening time obtained from all parental cultivars was inherited narrower and more stable variation than others fruit trait, with 0.92-3.41 in coefficient of variation. The heritability of fruit ripening time was calculated to be over 0.8 in almost all crosses and average fruit ripening time of seedlings from cross combinations could be predicted based on that of the parental cultivars due to its superior heritability relative to other fruit traits. The average ripening time was earlier than the mid-parental value in families obtained from cross combinations using at least one late-ripening cultivar as parent, indicating that the early-ripening trait was more likely to be dominant compared to the late-ripening trait. By contrast, average ripening time was clustered in families of crosses not only between mid-season and early-season cultivars, but also between mid-season and mid-season cultivars. There was highly significant relationship (at 0.68) between mid-parental and progeny mean fruit ripening time. The correlation between fruit ripening time and fruit weight was also highly positive and thus, the mid-parental fruit ripening time could be a potent criterion for indirect selection of fruit weight.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.80-88
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• 2020

This study was conducted to examine the effect by application method and concentration of the indole-3-butyric acid (IBA), which is auxin-based plant growth regulator, on the growth and runner plants production of strawberry in the greenhouse. The seedlings of strawberry were transplanted in the pot (150 ×135 × 90 mm) filled with coir medium on April 12, 2019. The IBA was applied with a foliar spray or drench as 50, 100, 150, and 200 mg·L^-1 (50 mL per plant), respectively. The treatment was started on April 29, 2019. The foliar spray and drench treatment of IBA were repeated at 2-week intervals for 9 weeks from the start date of treatment. At 9 weeks after treatment, the petiole length of mother plants was the shortest in the control. The number of runner plants showed a tendency to decreased in the foliar spray. The number of lateral buds showed a tendency to decreased in the IBA treatment, and the least in the foliar with 100 mg·L^-1. There was not significantly difference in the fresh and dry weights of the first and second runner plants. However, in the third runner plants, the fresh and dry weights were the greatest in the drench with 100 mg·L^-1. Therefore, when considering the growth of third runner plants and lateral bud suppression, the drench with the 100 mg·L^-1 could be better application method and concentration of IBA treatment for growth of the third runner plants and runner plants production of strawberry, and the results can be used as a basic research of plant growth regulator application to save the labor force and enhance the seedling quality in strawberry seedling stage.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1181-1186
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• 2013

Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, Chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This study examined the influence of air temperature during seedling growth on the time required to reach the first fruit maturity and yield of hot pepper. Seedling plants of 'Super Manita' hot pepper was grown in temperatures $2.5^{\circ}C$ and $5.0^{\circ}C$ lower than the optimum temperature (determined by the average of temperatures for the past 5 years). Seedlings were transplanted into round plastic containers (30-cm diam., 45-cm height) and were placed in growth chambers in which the ambient temperature was controlled under natural sunlight. The growth of seedlings under lowered temperatures was reduced compared to the control. The mineral (K, Mg, P, N) concentrations in the leaf tissues were higher when plants were grown with the ambient temperature $2.5^{\circ}C$ lower than the optimum, regardless of changes in other growth parameters. Tissue calcium (Ca) concentration was the highest in the plants grown with optimum temperature. The carbohydrate to nitrogen (C/N) ratio, which was the highest (18.3) in the plants grown with optimum temperature, decreased concomitantly as the ambient temperature was lowered $2.5^{\circ}C$ and $5.0^{\circ}C$. The yield of the early harvested fruits was also reduced as the ambient temperature became lower. The first fruit harvest date for the plants grown with optimum temperature (June 27) was 13 days and 40 days, respectively, earlier than that in plants grown with $2.5^{\circ}C$ (July 10) and $5.0^{\circ}C$ (Aug 6) lower ambient temperatures. The fruit yield per plant for the optimum temperature (724 g) was the greatest compared to those grown with $2.5^{\circ}C$ (446 g) and $5.0^{\circ}C$ (236 g) lower temperatures. The result of this study suggests that the growers should be cautioned not to transplant their hot pepper seedlings too early into the field, since it may delay the time of first harvest eventually reducing total fruit yield.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.58-68
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• 2001

This study was carried out to investigate the growth and biomass production of Abies koreana seedlings under different relative light intensity. The 5-year-old potted seedlings were grown for 24 months under different light intensity of 100%, 50%, 30%, 10% and 2% of the natural full light intensity. The results were as follows: 1. Height growth was similar in the seedlings under different light intensities except in 2% of the full sun light intensity, having shown the lowest height growth. 2. Root collar diameter growth was reduced gradually by decreasing of the relative light intensity. 3. The seedlings which were grown under relatively low light intensity showed the later starting date of the stem growth in the next spring and showed the smaller number of new needles, and the smarter number and the shorter length of new shoot of the seedlings. 4. Total dry mass including the dry mass of leaves, shoot and root was reduced by decreasing of the relative light intensity. 5. In case of the seedling grown in one year shading condition, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.99$\pm$0.25 to 1.06$\pm$0.06 and was not significally different among the seedlings grown under 100%, 50% and 30% of the relative light intensity. And the radio was ranged from 0.60$\pm$0.04 to 0.52$\pm$0.03 in the seedlings grown under 10% and 2% of the relative light intensity, respectively. In case of the seedling grown in two years shading, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.79$\pm$0.04 to 1.00$\pm$0.03 and was not significally different among the seedlings grown under 100, 50, 30% and 10% of the relative light intensity. And the ratio was 0.29$\pm$0.03 in the seedlings grown under 2% of the relative light intensity, respectively. 6. T/R ratio of the seedlings grown in one year shading condition was ranged from 3.35$\pm$0.33 to 4.61$\pm$0.25 and was not significantly different among the relative light intensities of 100%, 50%, 30% and 10%. The seedlings grown under 2% of relative light intensity showed the highest T/R ratio of 7.36$\pm$0.15. In case of the two years shadings the T/R ratio was ranged from 1.76$\pm$0.11 to 3.12$\pm$0.19 and increased as relative light intensity decreased except 2.01$\pm$0.14 in 2% of relative light intensity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.24-30
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• 2010

Comprehensive studies on seedling production and transplanting cultivation of waxy corn are necessary to fulfill the comsumer's preference for the high quality whole ear waxy corn and its year-round supply for higher price, and to escape marketing in a short period at harvest season. Two waxy corn hybrids (cv. Chalok# 1 and Chalok# 4) were used to study the effects of seeding date, nursery days and plug cell size on growth and yield of waxy corn, and to clarify the reliable transplanting date at the Experimental Field of the National Institute of Crop Science in 2007. The number of days from seeding to silking was increased as nursery days were extended, but the number of days from transplanting to silking was shortened comparing to the direct seeding. Number of days from seeding to silking was shorter by 9~12 days for Chalok# 1 than for Chalok# 4, while the number of days from seeding to silking was shorter by 12~15 days in the second cropping than in the first cropping. Culm length of transplanted waxy corns was decreased as the nursery days were extended. Culm length of seeded Chaok# 1 and Chaok# 4 were decreased by 17% and 24%, respectively, in the second cropping compared to those in the first cropping. Ear length was somewhat decreased as the nursery days were extended. Chalok# 1 in the second cropping the degree of decrease was much higher in second cropping than in first cropping of Chalok# 1. Comparing to the first cropping, number of marketable ears per 10a of Chalok# 1 decreased as high as 64%, while that of seeded Chalok# 4 decreased mere 12% in the second cropping.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.123-127
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• 1985

Incidence of the Fusarium wilt caused by F. oxysporum f. sp. vasinfectum of sesame (var. Kwangsan) was remarkably influenced by seeding date and mean air temperature in the field of two or three year's continuous cropping with sesame in 1983 and 1985. Sesame were seeded on six different dates from April 20 to July 5. Air temperature was checked daily at the meteorological station near the experimental field. Low($16{\sim}20^{\circ}C$) and high temperature($20{\sim}25^{\circ}C$) periods were provisionally devided, based on every ten-day mean daily temperature during field experiment for last ten years, which corresponded to before and after June 15 in Jinju, Gyeong-nam. Infection rates were 83.7%, 68.2% and 59.4% in the plants grown for 55 days (seeding date: April 20), 40 days(May 5) and 25 days(May 20) under low temperature. On the other hand, infection rates were below 3% in those plots seeded during high temperature period. The longer the growth period exposed to low temperature, the higher was infection rates. It is interesting to note that 40 days old seedling or older are prone to severe infection compared to the younger ones, in higher temperature of $20{\sim}25^{\circ}C$. Therefore, seedlings in vegetative growth stage are less prone to infection than these in reproductive growth stage. The result showed that air temperature during sesame growth was one of the most important factor affecting the incidence of Fusarium wilt. This suggested that sesame crop, which is of tropical origin, has been predisposed to Fusarium wilt, when the plants were exposed to low temperature of $16{\sim}20^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.1-29
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• 1969

Experiments on rice concerning it s varieties, fertilization, seedling dates and herbicides have been conducted to determine the most desirable method of direct sowing cultivation on dry paddy field land in the middle part of Korea. The results obtained at the Office of Rural Development of Choongnam Province are as follows:. 1. Sixteen different derivatives from the main varieties of low land rice were cultivated on a dry paddy field by the direct sowing method; at the same time, a few varieties were tried adopting the common transplanting cultivation method. The yield and yield factors from these two groups were examined to give the following results: a) Compared to the common transplanting cultivation, the direct sowing method showed remarkably increased number of panicles while the number of flowers per panicle was shown to be significantly decreased. The maturing ratio was detected to be lowered. The yield horn them differed according to the different varieties : good yield was obtained from Hokwang while Norin ＃25 proved poor when compared with the common transplanting cultivation method. b) Among sixteen varieties tested, Sunsou, Norin ＃25, Jaigou, Hokwang, Palkueng and Gosi showed comparatively high yields, their yield being more than 325 kilograms per 10 Are, but Nampoong, Paldal, Nongkwang, Norin ＃29, Eunbangju ＃101 and Shiro gane showed less yield, their yield being less than 271 kilograms per 10 Are, the relations between the yield and the yield factors can be summarized as follows; Number of varieties and their rice yield. 1) The varieties which were great in the, number of panicles and high in yield=Jaigoun, Hokwang Palkueng and Gosi. 2) The varieties which were low in the number of panicles and high in yield=Sounsou and Norin ＃25. 3) The varieties which were great in the number of panicles and poor in yield=Eunbangju ＃101 and Sirogane. 4) The varieties which were poor in the number of panicles and poor in yield: Nampung, Paldal and Norin ＃29. Number of flowers per panicle and yield. 1) The varieties which were great in the number of flowers per panicle and high in yield: Sounsou, Norin ＃25 and Gosi. 2) The varieties which were poor in the number of flowers per panicle and high in yield ; Jaigoun, Hokwang and Palkueng. 3) The varieties which were great in the number of flowers per panicle and poor in yield: Paldal and Nampung. 4) The varieties which were poor in the number of flowers per panicle and poor in yield: Norin ＃29. Eunbangju ＃101 and Sirogane. Maturing ratio and yield. 1) The varieties which were high in the maturing ratio and high in yield: Jaigoun, Sounsou, Norin ＃25 and Palkueng. 2) The varieties which were low in the maturing ratio and high in yield: Hokwang and Gosi. 3) The varieties which were early maturing rat io and low in yield: Hokwang and Gosi. 4) The varieties which were late maturing ratio and poor in yield: Eunbangju ＃101, Nampungand Sirogane 1, 000 grain weight and yield. 1) The varieties which were heavy in 1, 000 grains weight and high in yield=Norin ＃25 and Hokwang. 2) The varieties which were light in 1, 000 grains weight and high in yield=Sounsou and Jaigoun. 3) The varieties which were heavy in 1, 000 grains weight and poor in yield=Nongkwang and Eunbanju. 4) The varieties which were light in 1, 000 grains weight and poor in yield=Norin ＃29 and Sirogane. 2. The experiment on fertilization showed that the most desirable amount to be given per 10 Are was 10 kilograms of Nitrogen, 5 kilograms of phosphate and 6 kilograms of potassium; and when the Nitrogen given exceeded 8 kilograms, its effect was better when given in amsll consecutive (split) amounts, while the maturing ratio and the number of the flowers per panicle increased when Nitrogen was given in large amount during the later stage of growth of rice. 3. The experiment on the date and amount of seedling showed that the tested variety, Sunsou gave the best results when planted on the days between 25 April and 10 May. Eight liters per 10 Are were preferable if planted early and 12 liters per 10 Are if planted late. The reason why the later planting gave a lower yield was that the number of flowers per panicle was fewer. 4. The experiment on the irrigation for rice with direct sowing cultivation immersed in water showed that it was the most satisfactory when irrigated on 25th June, 55 days after its seedling, its plot giving the best yield. The plots 10th June and 15th July showed just as good results. However, irrigated later, than 15th July it showed lower yields. 5. Compared to the yield of the plot controlled by the common method, the yield from the plots treated with chemical herbicide such as LOROX, TOK, PCP, SWEP, Mo-338 on dry condition soil seemed poorer, but significant difference was not found statistically. On the other hand in the case where chemical herbicides such as TOK, Mo-338, Stam F-34 or ORDRAM were used after irrigation, the yield from the ORDRAM and TOK treated plots did not show significant differences compared to the common hand weed controling method, but those treated with chemicals other than the above showed a lower yield.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.88-99
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• 1996

In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.223-232
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• 2016

Drought is one of important environmental stress for plant. Drought has deleterious effect to plant growth including maize (Zea mays L.) such as vegetative and/or reproductive growth, root extension, photosynthesis efficiency, flowering, anthesis-silking interval (ASI), fertilization, and grain filling. In this study, we screened drought tolerant maize in 21 cultivars from different sources, sixteen NAM parent lines (B73, CML103, CML228, CML247, CML277, CML322, CML333, CML69, Ki11, Ki3, Ky21, M37W, Mo18w, NC350, Oh43 and Tx303), four Korean hybrids (Cheongdaok, Gangdaok, Kwangpyeongok and Pyeonganok) and one Southeast Asian genotype (DK9955). Drought stress (DS) index was evaluated with leaf rolling score at seedling stage and ASI at silking date. The leaf rolling scoring of CML228, DK9955 and Ki11 were determined 1.28, 1.85, 1.86, respectively. However, M37W, Kwangpyeongok, B73 and NC350 were determined over the 3. ASI analysis revealed that CML228, CML103, Cheongdaok, NC350, B73, CML322, Kwangpyeongok and Ki11 are represented less than 5 days under DS and less than 3 days of difference between DS and well-watered (WW), but CML69, Ki3, Pyeonganok, M37W, Mo18w and Gangdaok were represented more than 10 days under DS and more than 8 days of difference between DS and WW. Multi-Dimensional Scaling (MDS) analysis determined CML228, Ki11, and CML322 were regarded as drought tolerance cultivars. Eventually, Ki11 showed genetic similarity with Korean cultivars by QTL analysis and MDS analysis. Ki11 has a potential for development of drought tolerance maize with Korean cultivars.