• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.82-82
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• 2000

16세기부터 씌워진 과실봉지는 초기 병해충을 방지할 목적만으로 사용되었지만, 현재는 방균과 방충의 효과와 함께 자연현상의 최적화를 위한 차광성, 발수성, 투기성 및 투습성 등 을 조절하며 과실의 외관과 과중 및 당도에까지 영향을 미치는 바 과실봉지의 기능성 부여 를 위해서는 고도의 기술력이 요구되고 있다 하겠다. 실제 과실봉지를 적용하는 한 예로서 “배”를 들 수 있는데, 그 중 황금배는 흑반병, 각 종 병충해 및 동녹으로 인한 상품가치의 하락으로 현재 수요를 충족시키지 못하고 있는 실 정이다. 과피의 비정상적인 코르크화로 인해 발생하는 동녹은 과피의 물리적 할렬과 생리적 장해에 의해 발생하는 것으로 알려져 있다. 과실이 비대해짐에 따라 과피의 기공(과점)이 할 렬하면서 코르크화가 진행되는데 그 발생정도나 시기는 배의 품종에 따라 다르나 일반적으 로 코르크화는 기상조건, 특히 습도와 밀접한 관련이 있다. 황금배의 재배에 봉지를 적용하면 과피의 코르크화가 억제되는데 봉지 내의 대기 환경 이 외기보다 안정적으로 유지되고 직사광선이나 농약 및 마찰로부터 과실을 보호해 주기에 동녹이 어느 정도 방지될 수 있다. 만일 과실이 외부로부터 받는 자극을 적절히 조절하는 기능성 봉지가 제 역할을 다해줄 수 있다면 동녹을 방지하여 외관을 개선함은 물론, 배의 성장에 적합한 미시대기 조건을 제공함에 따라 보다 높은 당도를 지닌 대과의 재배가 가능 하다고 판단된다. 그러나 기존의 황금배봉지는 동녹의 정도를 완화시킬 뿐 완전히 방지할 수 없었으며, 봉지를 적용한 재배조건에서의 동녹 발생기구를 정확히 이해하지 못했었기에 효과적으로 봉지의 기능을 개선하는 것이 불가능하였다. 과실의 미려도는 과실의 맛과 함께 그 가치를 결정짓는 중요한 물성으로서 우리나라 황 금배 재배환경과 특성에 알맞은 배봉지의 제작이 선결될 때, 배 품질의 향상, 안정된 공급이 가능하게 될 것이며 아울러 농가의 수입증대와 수출 경쟁력 강화가 이루어질 수 있을 것으 로 판단된다. 이러한 측면에서 황금배 재배농가가 당면한 동녹발생의 문제점을 효과적으로 해결하고 아울러 기타 과실의 재배용 봉지의 기능성 부여를 위한 새로운 과실 봉지 처리 기 술의 개발이 절실히 요구되고 있다. 상기한 측면에서 본 연구에서는 과실봉지를 적용했을 때 봉지 내의 미시대기 조건이 봉 지의 특성에 따라 변화되는 양상을 파악하기 위해서 실험실적으로 field 조건을 모사하고 봉 지 내의 온도 및 습도를 측정 분석하였다. 아울러 봉지 종류간에 동녹발생 정도가 상이한 점에 예의 주시하여 다양한 봉지의 적용실험을 통해 최적의 과실봉지 조건을 탐색하였다.

• Research in Plant Disease
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• v.15 no.3
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• pp.230-235
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• 2009

Postharvest skin sooty dapple and decay disease of pear fruit often originates at small stain symptoms that occurred during harvest and handling. Experiments were conducted to characterize the effect of timing of application of disease control materials, and to evaluate sequential postharvest applications of fungicides or fungicides and bio-control agents. Fungicides and bio-control agents were increasingly less effective when the period between harvest and application was prolonged. Thiabendazole (TBZ) applied to fruit without artificial wounding or inoculation effectively reduced skin sooty and decay disease when applied within 3 weeks or 6 weeks in 2 years of study. TBZ, Fludioxonil and pyrimethanil were effective in controlling skin sooty and decay disease at artificial wounds inoculated with Cladosporium tenuissimum up to 14 days after inoculation. Application of TBZ at harvest followed 3 weeks later by application of Fludioxonil was superior to application of TBZ at harvest alone. Two bacterial biocontrol agents reduced skin sooty and decay disease at pear wounds inoculated with C. tenuissimum up to 14 days after inoculation with C. tenuissimum, but were ineffective when applied at 28 days after inoculation. Of possible sequential arrangements of fungicide and bio-control treatments, application of the most effective material promptly after harvest generally resulted in the highest level of disease control.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1006-1011
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• 1998

Volatile flavor components in three varieties (shingo(niitaka), mansamgil (okusankichi) and chuwhang pears) of Pear (Pyrus pyrifolia N.) were extracted for 24 hours with pentane-diethylether (1 : 1, v/v) using the LLEP (liquid-liquid extraction & perforation). Neutral fraction was separated from the extract and then analyzed by GC-FID and GC/MS equipped with a fused silica capillary column (Carbowax 20M, HP). Individual components were identified by mass spectrometry and their retention indices. The totals of 52, 47 and 22 volatiles were identified in shingo, mansamgil and chuwhang pears, respectively. Ethyl acetate, propyl acetate, hexanal, 1-hexanol, ethyl butanoate, ethyl-3-hydroxy butanoate, ethyl-2-hydroxy propanoate were the main components in each samples, though there were several differeces in composition of volatile compounds. Total contents of volatile components isolated in shingo, mansamgil and chuwhang pears were 6.972, 2.776 and 2.653 mg/kg of pears.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.37-48
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• 2012

This study was conducted to evaluate the effects of ground cover treatments on the nutrient contribution in a 'Niitaka' pear ($Pyrus$ $pyriforia$) orchard. Treatments included; 1) sod culture, 2) winter cover crop [ryegrass+hairy vetch], and 3) winter [ryegrass+hairy vetch]+summer [greensolgo (sudan grass ($Sorghum$ $bicolor$ L.))+ nemajanghwang (crotalaria ($Crotalaria$ $juncea$ L.)] cover crops. Ryegrass and hairyvetch were seeded with 6.4 kg/10a and 3.0 kg/10a, respectively, on October 17 of 2008, and greensolgo and nemajanghwang were seeded with 2.0 kg/10a and 3.0 kg/10a, respectively, on June 4 of 2009 at a diligent farmer in Boseong in Chonnam. Winter+summer cover crops provided greater amounts of dry weight, followed by winter cover crop and sod culture. The difference of amounts of dry weight from the ground covers affected to the levels of total N, P, and K contents, which were greater nutrient levels than those of recommended nutrient requirement for satisfying 10- to 12-year-old pear tree growth. Greater amounts of dry weight from the ground covers increased organic matter and concentrations of K and Mg in soil. Foliar nutrient concentrations, as an indicator of nutrient status of a tree, were not affected by application of ground cover treatments.

• Food Science and Preservation
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• v.20 no.2
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• pp.222-226
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• 2013

This study was performed to confirm physiological activities according to parts of new pear cultivars (Gamcheonbae, Manpungbae, Chuwhangbae, Hanareum) and Niitaka pear. The total polyphenol compound contents of pear peel, flesh and core were 178~235, 95~113, 177~229 mg/100 g as tannic acid equivalent, respectively. There were differences in the contents by cultivars, Chuwhangbae and Hanareum cultivars showed high contents. The total flavonoid contents of the pear peel, flesh and core were 29.2~40.2, 24.3~34.3, 26.9~38.8 mg/100 g, respectively and those of Chuwhangbae and Gamcheonbae cultivars showed comparatively high values. The electron-donating ability was high in Chuwhangbae, Gamcheonbae and in the pear peel (29.7~57.7%), core (29.1~38.2%), flesh (7.6~17.7%), in that order. The nitrate scavenging activity was highest in that pear peel (21.0~49.8%), followed by the core (11.8~16.2%) and flesh (7.8~9.7%), but there was little difference by cultivar.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.1
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• pp.51-58
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• 2014

Freezing hardiness of winter bud and branch of several pear (Pyrus pyrifolia) cultivars according to degree and duration of low temperatures was investigated by sprouting, electrolyte leaching rate and triphenyltetrazolium chloride (TTC). Sprouting rate as infected by degree and duration of low temperature were different between cultivars. The lower temperature, the longer duration, sprouting rate was decreased. Electrolyte leaching rate was showed above 30% at below $-30^{\circ}C$ treatment regardless of cultivars and duration. The lower temperature and the longer duration, Electrolyte leaching rate was increased. Electrolyte leaching rates of Manpungbae, Niitaka and Chuwhangbae at $-30^{\circ}C$ for 9 hours treatment which were observed high sprouting rate, were lower than those of other varieties. Absorbance rates by TTC test at $-21^{\circ}C$ treatment were 66.0 to 96.5% for 6 hours, 49.4 to 91.9% for 9 hours, and 37.3 to 89.4% for 12 hours. Freezing hardiness of pear cultivars at ecodormancy was different according to degree and duration of low temperature treatments.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.461-468
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• 2001

Impact between fruits and other materials is a major cause of product damage in harvesting and handling systems. The oriental pears are more susceptible to bruising than other fruits such as European pears and apples, and are required more careful handling. The interest in the handling of the pears for the processing systems has raised the question of the allowable drop height to which pears can be dropped without causing objectionable damage. Drop tests on pears were conducted using an impact device developed by authors to estimate the allowable drop height without bruising. The impact device was constructed to hold in a selected orientation and to release a fruit by vacuum for dropping on to a force transducer. The drop height was adjustable for zero to 60 cm to achieve the desired distance between the bottom of the fruits and the top of the impact force transducer. The transducer was secured to 150 kg$\sub$f/ concrete block. The transducer signal was sampled every 0.17 ms with a strain gage measurement board in the micro computer where it was digitaly stored for later analysis. The selected sample fruit was Niitaka cultivar of pears which is one of the most promising fruit for export in Korea. The pears were harvested during the 1998 harvest season from an orchard in Daejeon. The sample fruit was selected from two groups which were stored for 3 months and 5 months respectively by the method of current commercial practice. The pears were allowed to stabilize at environmental condition(18$^{\circ}C$, 65% rh) of the experimental room. One hundred fifty six pears were tested from the heights of 5, 7.5. 10 and 12.5 cm while measurement were made of impact peak force, contact time, time to peak force, dwell time, pear diameter and mass. The bioyield strength and modulus of elasticity were measured using UTM immediately after each drop test. The allowable drop height was estimated on the base of bioyield strength of the pears in two ways. One was assumed the peak force during impact test increasing linearly with time, and the other was based on the actual drop test results. The computer program was developed for measuring the impact characteristics of the pears and analyzing the data obtained in the study. The peak force increased while contact times decreased with increasing drop height and contact times of the sample from the hard tissue group. The allowable drop height increased with increasing bioyield strength and contact times, and also varied with Poisson\`s ratio, mass and equilibrium radius of the pears. The allowable drop height calculated by a theoretical method was in the range from 1 to 4 cm, meanwhile, the estimated drop height considering the result of the impact test was in the range from 1 to 6 cm. Since the physical properties of fruits affected significantly the allowable drop height, the physical properties of the fruits should be considered when estimating the allowable drop height.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.85-99
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• 2017

The study was compared for ability to supply macro-nutrients between time and height of mowing to establish alternate technique of a chemical fertilizer with 9-year old 'Niitaka' pear (Pyrus pyrifolia Nakai) trees in a pesticide-free orchard in 2009. Rye and hairy vetch were sown together during fall 2008. Four types of mowing time treatments were included; mowing on April 18+May 28, on April 28+June 8, on May 8+June 18, and on April 18+May 18+June 18. Mowing height treatment included mowing at $3{\pm}1cm$, $7{\pm}1cm$, and $13{\pm}1cm$ on April 18 or June 8. Mowing on May 8+June 18 increased the most dry weight of ground cover and vegetation to 14,480 kg per ha among the mowing time treatments, resulting in the greatest production of T-N (total nitrogen; 292 kg) and K (396 kg) per ha on the soil. Mowing at $7{\pm}1cm$ decreased the most dry weight of ground cover and vegetation to 11,970 kg per ha among the mowing height treatments, resulting in the lowest production of T-N (265 kg), P (111 kg) and K (333 kg) per ha in a soil. Ground cover treatments increased soil organic matter contents, regardless of mowing treatment methods.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.354-357
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• 2009

"Wonkyo Na-heukseong 2" was selected from a cross between "Kiyomaro", late season European cultivar with highly resistance and "Mansoo", late season Asian cultivar with long storability, large size and low susceptibility to pear scab made in 1997 at the National Institute of Horticultural & Herbal Science of Rural Development Administration in Korea. "Kiyomaro", released cross between "Taiheiyo" and "Bartlett" with scab resistance caused by Venturia nashicola in Japan, with no visual symptoms on any leaves was used as scab resistant source after field investigation and artificial inoculation test during 1997~1999. "Wonkyo Na-heukseong 2" blooms 1 day earlier than "Mansoo" and 3 days later than "Kiyomaro" in 2008. It is strong in tree vigor and upright-spreading in tree habit. It is classified as highly resistant to pear scab as "Kiyomaro" and "Bartlett", and cross-compatible with parental variety and Korean major pear varieties such as "Niitaka" and "Wonwhang". The average optimum harvest time of "Wonkyo Na-heukseong 2" was approximately 180 days after full bloom and it matured about 20 days shorter than parental varieties. The fruit is spindle in shape and yellowish greenish brown in skin color. Average fruit weight was 484 g and soluble solids content was $13.2^{\circ}Brix$. The flesh had medium to high juice and negligible grit. Its fruit was crisp like Asian pear.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.100-106
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• 2023

In order to control the fire blight disease, all plants within the radius of the diseased orchard were removed in the early stage of the outbreak, or antibiotics control was performed for prevention. Since the beginning of antibiotics use on plants, the potential for development of resistance to antibiotics by the plant pathogen and unintended detrimental effects on the fruit trees and environment has become a problem. The purpose of this study is to determine the degree of phytotoxicity to fruit trees caused by excessive spraying of the fire blight disease disinfectant and to establish basic data for safe disinfectant guide. We analyzed whether damage to the fruit tree and the maximum residual limit of fruit was exceeded when three kinds of the fire blight disease disinfectants were continuously sprayed in excess of the number of safe use during the growing season. There was no phytotoxicity in apple 'Fuji' and pear 'Niitaka', and oxolinic acid was detected beyond the limit of quantitation in 'Fuji' grown without a bag, and the other disinfectants were detected below the maximum residue limit. When these disinfectants are continuously sprayed in excess of the number of safe, phytotoxicity may remain on the fruit. Therefore, it is necessary to observe the prescribed dilution factor and observe the safe frequency and the timing of use.