• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.151-158
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• 2015

This study was conducted to know the variation and relationship of rice grain quality and starch pasting properties by transplanting times. Two early maturing rice cultivars which accounted for the most area of early maturing rice cultivar in Chungnam province were used. The experiment was laid out in a split-plot design with 3 replications. The main plot consisted of three transplanting times viz. early (April 25), ordinary (May 25) and late (June 25) with sub-plots containing two cultivars. According to the transplanting times, most of rice grain quality and starch pasting properties showed significant difference and Joami showed higher grain quality than Unkwang in all transplanting times. Especially, rice grain quality was improved when transplanted late, showing high head rice and glossiness of cooked rice due to the lower mean temperature during grain filling stage. Glossiness of cooked rice was positively correlated with head rice ratio, amylose content and setback value, and negatively correlated with chalky rice ratio and protein content. The highest positive and negative correlation were observed between breakdown value and peak viscosity ($r=0.98^{**}$), and breakdown and setback ($r=-0.94^{**}$), respectively. These results provide some information for rice researchers and producers producing cultivars with an improved quality, suggesting that rice quality is highly influenced by temperature at grain filling stage, and transplanting times is crucial in improving rice quality. In addition, starch pasting properties are useful for determining rice quality because rice grain quality and starch pasting properties are dependent on each other.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.198-198
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• 2017

Cultivated varieties of sweet potato were from dry texture type to tender texture type on the basis of consumer preferences. There are many differences in the quantity of sweet potato, starch content, pigment, and sugar content depending on the cultivation season and area, even in the same variety. Therefore, in this study, we attempted to establish optimum time of harvesting through growth characteristics and variation in component like starch, sugar, polyphenol and flavonoid. Four sweet potato varieties were used in this experiment. Among them, Jinhongmi (JHM) & Yulmi (YM) were as dry texture type and Pungwonmi (PWM) & Hogammi (HGM) were as tender texture type. Sweet potatoes were transplanted on 23 May, 2016 and were investigated storage root weight and component contents every 20 days from 60 days to 120 days and surveyed yield at 110, 120, 130 days after transplantation. Result revealed that storage root weight of YM, JHM, and HGM were 30.1, 38.9, 20.8 g respectively in 60 days after transplanting. Storage roots of PWM gerw faster with the weight of 88.2 g. In 120 days after transplanting, storage root weight varied from 88.3 to 118.7 g, HGM was the smallest, and PWM was the largest. Sugar contents of sweet potato ranged from 21.0 to $23.8Brix^{\circ}$ in 60 days after transplanting and from 27.5 to $30.78Brix^{\circ}$ in 120 days after transplanting. In particular, the sugar content of HGM was the highest over $30Brix^{\circ}$ after 80 days. The starch content of dry texture type (YM, JHM) increased from 15.5% to 20.4% and tender texture type (PWM, HGM) increased from 11.0% to 17.3%. Starch content tended to be high in dry type sweet potatoes. The content of polyphenol and flavonoid were highest in 60 days after transplanting and was reduced according to cultivation period. The total yield of PWM was high as 3,154 kg/10a and large storage root of over 250 g accounted for 47.4% in 110 days after transplanting. Storage root (YM, JHM, HGM) of 81~150 g accounted for 34.9% ~ 43.2% in 120 days after transplanting. These are the most marketable. Because consumer in Korea prefers small, round and about 100g size sweet potato. The ratio of large storage root (over 250 g) were increased in all varieties at 130 days after transplanting. Therefore, it is considered appropriate to harvest PWM at 110 days and YM, JHM, HGM at 120 days after transplanting, which planted in late May.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.230-236
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• 1992

To study the effects of different nursing methods and transplanting on the growth of the rice plant(Oriza sativa L.hn southern region of Korea, Kumo-byeo, Palgong-byeo and Dong-jinbyeo were transplanted from April 20 to July 20 with 15 days intervals as 8 days seedling (infant rice), 25 days box seedling for machine transplanting and 45 days conventional seedling, respectively. No. of leaves at transplanting were in order of 45 days seedling>25 days seedling>8 days seedling. In 25 days seedling, they were increased as transplanting dates were later from April 20 to June 5, and in 45 days seedling, it showed same tendency until June 5 with Dongjinbyeo, June 20 with Palgong-byeo and Kumo-byeo. Root activity according to the $\alpha$-naphthylamine oxidation activity and rooting activity were higher in order of 8 days seedling>25 days seedling>45days seedling. Panicle formation initiated after maximum tillering stage as transplanting at April 20 with 8 days seedling and 25 days seedling, but it intiated before maximum tillering stage as transplanting at July 20 in Kumo-byeo. and in Palgong-byeo intiations of panicle formation were shown after maximum tillering stage as transplanting until May 20, but June 5 in Dongjin-byeo. However, there was no significant tendency with 45 days seedling. Missing hill ratio were less than 5% as transplanting with 8 days seedling and 25 days seedlingregardless of transplanting periods or varieties.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.134-135
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• 2005

• Journal of Biosystems Engineering
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• v.23 no.4
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• pp.319-326
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• 1998

A herbicide applicator attached to a rice transplanter was developed to perform herbicide application and transplanting simultaneously. The prototype machine was composed of herbicide tank, discharge device, spinner, scattering plate and power drive. The application rate of the machine could be adjusted from 10 to 30 kg/㏊ and the application swath was 1.8m. According to the field test, application uniformity showed the range of 13.6~43.9％ in terms of CV(coefficient of variation) depending on the spinner speed, application height and shape of diffuser. The best uniformity could be achieved with the spinner speed of 30.8m/s and application height of 20cm. Field efficiency of the prototype was 4.7hr/㏊. Transplanting machine has field efficiency of 4.6hr/㏊ in Korea. By attaching the herbicide applicator, field efficiency became lowed only by 0.1hr/㏊, which was counted for filling time of herbicide. Simultaneous operation of transplanting and herbicide application had a of labor saying. The weed control efficacy was measured to be 96% in field when AC140 + Stomp and Londax + YRC was applied at the 65th day after transplanting. Nonanmae was treated by manual application to be compared to.

• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.49-56
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• 1986

To obtain the information of low chlorine leaf production, the chlorine content of the soil and cured leaf in Burley tobacco growing area was investigated. The results obtained are as follows. 1. The chlorine concentration in soil at transplanting time in Kwang-ju growing area was higher than in Jeon-ju(1983), and paddy field sell showed higher concentration of chlorine than upland field in Jeon-ju(1984). The chlorine concentration in soil was different between years, locations, and cultivated land (paddy field and upland field), but the concentration, on the whole, was under the levels that might effect the leaf quality. 2. The chlorine concentration In soil was highest around todays after transplanting, and after harvesting, the concentration decreased to half of transplanting time. 3. The distribution of chlorine through the parts of tobacco plant showed remarkable difference between years, locations, cultivated land and growing stages. 4. There was significant positive correlation between chlorine concentration in top soil and chlorine content of cured leaf. 5. Chlorine content of cured leaf in Kwang-ju area(1.79%) was higher than that of Jeon-ju area(O.79%), relatively. 6. It was considered that the accumulation of salt from the sea by sea. wind did not main factor of high leaf chlorine content in seaside district.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.7-13
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• 1985

Effect of the two PVY strains(PVY-VB and PVY-VN) on yield and chemical constituents of tobacco plants was determined in roar. NC2326 and Burley 21. The virus was inoculated 6 and 8 weeks after transplanting, respectively. The strains and time of inoculation were most critical factors for yield reduction. The greatest reduction was caused by the necrotic strain (PVY-VN) inoculated 6 weeks after transplanting, accounting for the loss of 40% in var. NC2326 and of 45% in var.. Burley21. When inoculated 8 weeks after transplanting with the necrotic strain, only 17% reduction was recorded in roar. Burley21, but no reduction occurred in roar. NC2326. Generally less reduction was caused by the PVY-VB strain, ranging 12-16% depending on the time of inoculation and/or variety. Compared to healthy tobacco, PVY infected tobacco contained higher concentrations of total nitrogen, protein nitrogen, nitrate nitrogen, and lower total sugar in cured leaf of roar. NC2326. Total alkaloid, P, Mg, Ca, and K levels were not altered. In var. Burley21, protein nitrogen and nitrate nitrogen increased, but other chemical components were not changed. Necrotic strain-infected tobacco with a severe symptom had higher nitrogen than did mild strain-infected tobacco.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.19-22
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• 2008

This experiment was conducted at Sangji university in Wonju, Korea from 2005 to 2006. The results obtained were summarized as follow; The Chung-ju local variety was tested to find out the possibility of transplanting of seedling as a after-barley crop. When transplanting of seedling for a after-barley crop was test, this short-day plant flowered from september 1 to september 3, showing no connection with sowing time nor seedling periods. The yield of seeds per 10a was affected by both the sowing time and the seedling periods and its peak in the plots sowed on May 15 and transplanted on June 24(40 days seedling).

• Horticultural Science & Technology
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• v.18 no.6
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• pp.787-791
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• 2000

Lettuce seedlings used in this investigation of planting distance and labor-saving efficiency were first grown in 100-hole paper trays for 30 days. Seedling height for transplanting ranged from 3 cm to 6 cm and plants had 3 to 5 leaves. The beds prepared for transplanting were of the arched type and were 35-40 cm in width, 15-20 cm in bed height, and between-bed furrow width was 20 30 cm. Typical seedling planting depth with the transplanter was 4-5 cm, although depth was quite variable because of the irregularities of the ground. Total transplanting time with the transplanter varied from 2.6 to 2.7 hours per 10a, while it took 38.1 hours per 10a with conventional planting. It was critical that the condition of both the seedlings and the bed be adjusted to the transplanter before planting. Considering yield and inter-plant distance, optimal transplanter performance resulted with $60{\times}20cm$ or $60{\times}25cm$spacing, and the labor-saving efficiency using the transplanter was improved by over 93% of that of conventional planting by hand.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.19-24
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• 2010

The experiment was implemented to introduce the drainage electrode irrigation system as early as possible after transplanting in order to save the nutrient solution in a convenient way. Drainage electrode irrigation method was introduced 15, 19 or 22 days after transplanting after irrigation was firstly controlled by time clock. Time clock method was also treated as a control plot. Drainage electrode method could be adopted from 15 days after transplanting, 15 days earlier than the present introducing time. The growth and yield was better in treatments with drainage electrode method. Water and fertilizer use efficiency were the highest in the treatment of 15 days, the lowest in time clock treatment.