• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.21-24
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• 2010

In recent years, many agricultural scientists are studying on eco-friendly farming methods. Among of lots of the methods, the natural insecticides are highly motivated and interested due to their safety and biodegradable issues, and readily available source of bioinsecticides. In this study, the crude extract of custard apple (Annona reticulata L.) seed and its three fractions which were separated based on polarity indexes were examined for their insecticidal activities against Myzus persicae Sulzer and Nilaparvata lugens S.. The crude extract (Aceton/MeOH) showed strong insecticidal activities against both insects at 3.00 mg/mL ($LD_{50}$=0.45mg/mL for M. persicae S. and 1.42 mg/mL for N. lugens S.). Furthermore, simple fractionation with hexane, chloroform, and water lead to increase three-folds insecticidal activity on chloroform fraction ($LD_{50}$=0.13mg/mL for M. persicae S. and 1.14 mg/mL for N. lugens S.). The results suggest that A. reticulata extracts might be used to control for M. persicae effectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.169-173
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• 2006

This study used loess from the source region of Asian dust (a desert area in China) to analyze the effects of Asian dust on fruiting and fruit quality in Korean fruit trees. Asian dust and loess from the source region were highly alkaline compared to average Korean field soil. Organic material contents of Asian dust were about three times as high as that of the average field soil. Loess was dusted onto the stigma of apple, pear, and peach trees. fruiting, seed number, fruit quality and pollen tube elongation were investigated. Pollination and fertilization were not influenced while pollen tube elongation was slightly influenced. Consequently, fruiting, seed number and fruit quality were not affected by the dusting treatment.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.341-348
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• 2018

To investigate the effect of light sources on the growth and photosynthesis of the dwarf apple rootstock M.9 for the production of standard seedlings, the plants were cultivated in a controlled environment for 6 weeks. The sources of light are six treatments [Red (R), Blue (B), White (W), RBUV (R7B3 containing UV-A), RBW (R3B1W1), SMF (high pressure sodium + metal halide + fluorescent lamp) under $154{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth characteristics of apple seedlings varied depending on artificial light source at 3 weeks and 6 weeks. The plant height of apple seedling was high in the R, RBUV, RBW, and SMF light sources at 3 weeks, and in the R light at 6 weeks. There was no significant difference on stem diameter among the treatments at 3 weeks, but showed high in RBUV and RBW light at 6 weeks. Leaf number was the highest in RBUV light at 3 and 6 weeks. The chlorophyll content (SPAD value) was high in the B and RBUV light at 3 weeks, but it was not significant at 6 weeks. The growth rate to height of the R light (1.12mm/day) was the highest among the treatments, followed by RBUV, RBW, SMF, W and then B. Leaf area was the highest in RBUV and RBW lowest in B. Specific leaf area was high in W and fresh and dry weight were high in RBUV. The photosynthetic rate at 6 weeks was highest in the B and lowest in the R. Stomatal conductivity and transpiration rate were higher in the B and W compared to the other light sources. Therefore, we are considered that light sources for growth of dwarf apple rootstock M.9 seedlings are suitable the R, RBUV, and RBW light sources with a high mixing ratio of Red and Red +Blue.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.128-135
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• 1998

The experiment was carried out to obtain basic informations on sod culture using water foxtail in apple orchard at Kyeongbuk Provincial RDA in 1996 to 1997. Period of seedling emergence varied with sowing time and accumulative temperature. Sowing at Nov. 25 required longer than 100 days, while it needed only 8 days when water foxtail was sowed at Sep. 20. In a view of accumulative temperature, sowing at March 15 needed $139^{\circ}C$ but it required about $1,000^{\circ}C$ at August 10. This result showed that the seed of water foxtail has strong summer-dormancy in natural condition. Water foxtail had s-shape growth curve during growing season, and growth rate was the highest from March to May in this period. Plant height increased 2 times and 4 times for dry weight from March 20 to April 20. However, growth was decreased by summer depression after May. Major weeds in apple orchard were horseweed, akino-nogeshi and shepherd's-purse. These species were suppressed by the dominance of water foxtail. Water foxtail as a cover plant could be used for a method of weed control instead of herbicide in apple orchard.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.8-13
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• 1985

Egremont russet 사과 품종(品種)의 종자에 여러가지 종피(種皮) 파상(破傷)을 한 후 발아(發芽), 유아(幼芽), 유근(幼根)의 생장(生長)과 생리적(生理的)인 왜화(矮花)에 대(對)하여 조사한 결과 다음과 같은 결과를 얻었다. 자엽(子葉)의 크기를 1/2로 절단하고 종피(種皮)를 제거(除去)한 Egremont russet 사과 품종(品種)의 종자(種子)에 $GA_3$를 처리한 것은 평균발아율(平均發芽率)이 55%였으며 동일조건(同一條件)에서 대조구(對照區)는 45%였다. 그리고 종피(種皮)가 완전(完全)한 것과 종피파상(種皮破傷)을 한 구(區)에서는 낮았다. 유아장(幼芽長)은 종피(種皮)를 완전히 남긴 것과 파상(破傷)한 구(區)에 $GA_3$를 처리하였을 때 촉진(促進)되었으나 전체적(全體的)으로 볼 때 종피(種皮)를 제거(除去)한 구(區)에서 더 길었다. 그러나 유근장(幼根長)은 $GA_3$처리에 의(依)해서 억제(抑制)되었으나 유근(幼根)의 직경(直徑)은 더 커졌다. 그리고 생리적(生理的)인 왜화(矮花)는 종피(種皮)를 남긴 구(區)에서 발생(發生)되었으며 $GA_3$ 처리에 의(依)해 극복되지 않았다. 자엽(子葉)의 녹색화(綠色化) 속도는 종피(種皮)를 제거(除去)하고 자엽(子葉)의 크기를 1/2로 절단한 구(區)에서 촉진(促進)되었다.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.142-146
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• 2017

In Korea, kiwifruit is grown within a limited region on the southern coast where the climate is warm. Since the yellow - fleshed kiwifruit variety, 'Hort16A', first became commercially available, we have focused on breeding additional yellow - fleshed kiwifruits. Here, we describe the cultivar 'Goldone', which originated from 'Red Princess' and is characterized by red coloration around the fruit core. Conventional field crosses were performed in 2003, and permission for final release of 'Goldone' was obtained in 2011. This cultivar is very productive, with an average fruit weight of 129 g, which is 39% heavier than that of the cultivar 'Hayward'. 'Goldone' is harvested in late October, approximately 165 - 170 days after anthesis. In general, 'Goldone' has approximately eight flowers per fruiting shoot; these flowers must be thinned before blooming for commercial production. 'Goldone' was registered at the Korean Seed & Variety Service in 2014 for plant variety protection rights (grant no. 4835).

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.41-46
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• 1989

The seeds of Malus sieboldii were collected in late fall of 1988 and stored in cold stratification condition for 15 weeks. Growth regulators such as $GA_3$, BA and ABA were treated to the seed to know germination capacity and seedling growth. The results were as follows. 1) Higher germination was achieved in $GA_3$ and BA plots, But ABA treatment showed lower germination percentage and physiological dwarf and also induced to the secondary dormancy condition in partly. 2) Average length of time for germination was delayed over 2 days in ABA plot when comparing with the other plots. 3) Average length of plumule and radicle also was inhibited by ABA treatment. This means lower seedling vigor. 4) Fresh and dry weight of the seeding were higher in BA plot while ABA plot was lower and undesirable seedling was produced. From above mentioned results, it is believed that ABA treatment to the seed induced the secondary dormancy and physiological dwarf pattern. Therefore, utilization of BA can be produced the normal seedling, the authors believed.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.530-538
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• 2023

This study conducted an investigation into the effects of fruit type and cultivation practices (organic and conventional) on soil characteristics and soil arthropod communities within apple, blueberry, grape, peach, and pear orchards. The collection of soil arthropod communities was achieved through the utilization of pitfall traps, with concurrent measurements taken for soil moisture content, electrical conductivity, and temperature. The findings of this study unveiled substantial impacts attributed to fruit type and cultivation practices on soil characteristics. Specifically, within organic apple orchards, discernibly higher levels of soil moisture content, electrical conductivity, and temperature were observed when compared to their conventional counterparts. The investigation into soil arthropod communities yielded a total of 1,527 individuals, classified in to five phyla and 15 orders. The range of abundance, species richness, and diversity indices varied across conventional and organic orchards. Cultivation practices were found not to exert a significant influence on soil arthropod community characteristics. However, Non-metric Multidimensional Scaling (NMDS) analysis indicated a significant differentiation in soil arthropod community structure based on cultivation practices. This study underscores the importance of considering vegetation structure and environmental characteristics that may influence soil arthropod communities comprehensively when assessing the impact of cultivation practices on soil arthropods. Furthermore, it emphasizes the need to account for both the characteristics and structure of soil arthropod communities in understanding the implications of cultivation practices on these organisms.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.264-268
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• 2007

Flower and fruit characteristics, in 'Hongro' and 'Galaxy Gala' apples, were investigated by bearing branch lengths and flower bud position such as blow 5 cm, $10{\sim}15cm$ and above 20 cm length with terminal bud, and above 20 cm length with axillary bud for investigation on possibility of alternative use of long bearing branch and axillary bud in case of die-back of spur flower bud. In flowering characteristics by flower bud position in the above 20 cm length, the terminal bud was later and was short in flowering period, and also was little in number of flower per bud. Fruit weight, number of seeds, and sugar-acid ratio, in characteristics of ripening fruit, were more the blow 5 cm and $10{\sim}15cm$ length, but soluble solid and malic acid contents was the opposite tendency. In fruit characteristics by flower bud position in the above 20 cm length, the terminal bud had high tendency expected far number of seed in 'Hongro' and Hunter a value of 'Galaxy Gala' apple but had not significant difference. Correlation between fruit weight and number of seed was high. As the results, value of alternative use of long bearing branch in apples had a little expected for fruit weight, especially was more 'Galaxy Gala' and the axillary bud.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.35-41
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• 2006

Possible application of hurdle technology extention of shelf-life of fresh-cut apples was investigated by evaluating various hurdle factors known to be effective microbial growth inhibitors and their synergistic effects. Fresh-cut apples treated with chitooligosaccharide or grapefruit seed extract (GSE) showed higher microbial counts than those treated with distilled water during latter half of storage period, and at high concentrations. Citric and malic acids showed similar results, although microbial counts of fresh-cut apples treated with 0.75% or higher concentration of citric acid increased at 4 days of storage at $18^{\circ}C$, indicating malic acid is more effective than all hurdles tested for controlling microbial growth. Using ascorbic acid and calcium chloride as additional hurdles to control browning and softening, minimum and maximum compositions of dipping solution were: 0.25 : 0.5 : 0.25% and 0.75 : 1.0 : 0.75% malic acid: ascorbic acid: calcium chloride, respectively.