This study investigated the effects of several fruit size factors on quality changes and the incidence of internal physiological disorders during the simulated export and distribution of 'Wonhwang' pears (Pyrus pyrifolia Nakai), the main early-season variety of Korean pear for export. Experiments were conducted on fruits packed (5 kg base) in four different grades of export standards at the Cheonan Pear Export Sorting Facility in 2023. All packaged fruits were stored at 1 degrees C for 30 days to simulate export transportation, followed by a simulated shelf life at 25 degrees C for 21 days. The soluble solids content did not vary by size, but the titratable acidity was lowest in the smallest fruit (Size 10) over the entire shelf lifetime. In addition, Size 10 fruits showed a higher respiration rate and greater ethylene production than fruits of other sizes. It was also found that the largest fruit (Size 7) and smallest fruit (Size 10) had lower levels of ethanol-insoluble substances than the medium-grade fruits of Sizes 8 and 9. The incidences of physiological disorders for fruits designated as Sizes 8 and 9 were lower in with regard to core browning and flesh browning compared to the largest fruit (Size 7) and smallest fruit (Size 10). Fruits of Size 8 and size 9 were judged to be the most suitable export standards for 'Wonhwang' pears.

The purpose of this study is to identify the different effects exerted by planting density and nitrogen fertilization on high-salinity reclaimed paddy fields (RPF) and general paddy fields (GPFs), and to find the amount of fertilization and the planting density suitable for the growth of forage rice in each paddy field. Nitrogen fertilization with high-salt and low-salt soils, an untreated control plot, treatment with 200 kg/ha, 300 kg/ha, and 400 kg/ha, and planting densities of 30 cm × 10 cm and 30 cm × 16 cm, growth, and feed values were investigated. In both experimental locations, there was no significant change in the soil due to N treatment, but in the case of RPF, electrical conductivity (EC) decreased significantly from more than 5 dS/m to up to 2.87 dS/m during the yellow ripe stage due to the influence of floods and concentrated precipitation in the fields. In all soils, as both the amount of N treatment and the planting density increased, there was a proportional relationship in which the number of tillers and the dry weight also increased, with the occurrence of lodging also being increased. The dry weight, as expected, was 1.5 times higher at a planting distance of 10 cm, rather than 16 cm. In addition, in both locations, the N treatment led to an increase in the dry weight, but when N treatment reached 400 kg/ha (2.0), the dry weight decreased instead. Moreover, although there was no clear difference in feed value according to N treatment, in RPF, the neutral detergent fiber (NDF) was higher than 60%, the relative feed value (RFV) was less than 98, and the total digestible nutrient (TDN) was also low, confirming that the quality of rice was higher in GPF.

Soil salinity is a key factor to limiting agricultural products throughout the world, especially in arid and semi-arid areas, since it intervenes with plant morpho-physiology, resulting in reduced growth and development, as well as disruption of ion homeostasis. This work examined the effects of salinity stress on the mono-cropping of T. pratense, F. arundinacea, and M. sativa and CaSO4 and MgSO4 on the mixed-cropping of T. pratense and F. arundinacea under saline conditions. Plants were assessed by dry weights, physiological parameters (photosynthesis rate, SPAD, SLA), forage quality, and ion concentrations. The biomass of all mono species decreased under salinity, except M. sativa, and mixed cropping was affected less than mono-cropping. The values of the mono-cropping of SPAD were decreased in the long term, and SLA was higher than the control in mixed cropping, with the photosynthesis rate of mono-cropping being higher in medium salinity in the long-term; moreover, CaSO4 and MgSO4 enhanced the photosynthesis rate of mixed cropping. Overall, we concluded that M. sativa is tolerant to medium salinity, and mixed cropping plus MgSO4 and CaSO4 were efficient under salinity stress.

본 연구는 우리나라 대표 수출 포도 품종인 ‘캠벨얼리’ 를 대상으로 에틸렌작용억제제인 1-methylcylopropene(1-MCP)과 에틸렌생합성 저해 효과를 지닌 salicylic acid(SA)를 단독 혹은 병행처리하여 과실의 저장 및 유 통환경에서 발생하는 탈립, 갈변 및 부패 등 생리장해의 발생과 과실 품질에 미치는 영향을 에틸렌 발생물질인 에테폰과 비교하여 검토하였다. 1-MCP 1,000ppb 훈증 처리 후 SA 25μM을 살포 처리하고 19°C에서 16일간 저장한 후 조사한 과립경도 및 산함량 수준은 단용처리 에 비하여 높게 나타났다. 탈립률은 100μL·L-1 에테폰 처 리구 41.7%, SA 처리구 40.8%, 1-MCP 처리구 38.2%로 나타났으나 1-MCP 처리 후 SA를 처리한 경우는 18.7% 로 탈립방지 효과가 월등하였다. 브러쉬의 길이를 측정 한 결과, 에테폰 처리구는 1mm 미만의 비율이 74.3%로 매우 높게 나타났던 반면, 1-MCP 처리 후 SA를 처리한 경우는 2-4mm의 비율이 22.8%, 4-6mm 비율이 27.9% 로 브러쉬 길이가 길게 조사되었다. 과축의 무게는 에테 폰 처리구에서 2.3g으로 가장 낮아 감모율의 증가에 미 치는 에틸렌의 영향과 1-MCP 및 SA의 감모 억제효과 를 확인할 수 있었다. 또한 1-MCP와 SA는 저장 중 ‘캠 벨얼리’ 포도의 줄기갈변 억제 및 부패 경감에 일부 효 과가 있음을 확인되어 추후 수출시 품질유지를 위한 기 술 적용이 가능할 것으로 판단되었다.

This study was conducted to compare the effect of salicylic acid (SA), an ethylene biosynthesis inhibitor, and the 1-methylcyclopropene (1-MCP) fumigation, to prevent fruit quality deterioration and physiological disorders during the shelf-life of Korea’s leading export grape variety ‘Campbell Early’. The berries treated with SA after 1MCP fumigation (1-MCP+SA) showed a higher firmness value and titratable acidity than single treatment of SA or 1-MCP. The rate of shattered berry was high as 41.7% for 100ppm ethephon spray, 40.8% for 25μM SA, and 38.2% for 1,000ppb 1-MCP, but showing only 18.7% when the SA was applied after 1-MCP fumigation. The ratio of short brushes less than 1mm was largest at 74.3% for ethephon treatment, while 1-MCP+SA treatment was found to have the longest brush length among all treatments, with a 2-4mm ratio of 22.8% and a 4-6mm ratio of 27.9%. The weight of rachis was found to be the lowest at 2.3g in the ethephon treatment, and the reduction of rachis weight loss per cluster by 1-MCP+SA treatment was evident. In addition, 1-MCP+SA treatment were effective in mitigating stem browning and berry decay during the 16-day storage period at 19C in this cultivar, so it is believed that they can be used as a practical post-harvest treatment in grape exportation. Additional key words : berry decay, brush length, rachis browning, soluble solids

We examined the effects of pre-drying rates, delayed cooling, and carbon dioxide (CO2) treatment on skin blackening, a major physiological disorder during cold storage in Asian pear (Pyrus pyrifolia Nakai) ‘Chuhwangbae’. Total skin blackening incidence was calculated as the percent disorder index (PDI). PDI significantly decreased with increasing pre-drying rate: the highest PDI was 37.3 for the 1% pre-drying treatment and the lowest PDI was 5.1 for the 4% treatment. Meanwhile, the 5% pre-drying treatment did not show a statistically significant difference from the 4% treatment. A 48-h cooling delay at 20°C was the most effective treatment for preventing skin blackening. PDI after cold storage at 1°C was 6.2, 9.2, and 19.1 for 48-h delay, 24-h delay, and no delay, respectively. In the CO2 treatment, 2% CO2-treated fruit showed rapid disorder symptoms from eight days after cold storage at 1°C, and the PDI increased to 19.6 at 12 days and to 63.2 at 20, which was three times higher than the untreated fruits. A decrease in total phenolic content appeared more pronounced in the tissues treated with 2% CO2, while polyphenol oxidase (PPO) activity in untreated fruits increased with increasing skin blackening incidence. However, there was no increase in PPO activity with the 2% CO2 treatment, skin blackening appeared to be a CO2 injury rather than enzymatic oxidation. Additional key words: CO2 injury, peroxidase, polyphenol oxidase, pre-conditioning, storage

In this study, we evaluated the changes of fruit quality indices during fruit development and ripening in Korean new pear cultivar ‘Changjo’, developed from a cross between ‘Tama’ and ‘81-1-27’ (‘Danbae’ × ‘Okusankichi’) in 1995 and named in 2009, to determine appropriate harvest time and to enhance the market quality and broaden the cultivation area. The fruits of ‘Changjo’ pears harvested from 132 days after full bloom (DAFB) to 160 DAFB. Fruit growth and quality indices were monitored at 1 week interval by measuring fruit weight, length, diameter, firmness, and taste related quality indices. The calculated fruit fresh weight increased continuously with fruit development and reached to an average of 594g on Sep. 20 (160 DAFB). The ratio of length to diameter declines as fruit maturation progress, resulting in 0.898 for ripe fruit stage as a round oblate shape. Flesh firmness of ‘Changjo’ pears showed over 30N until 153 DAFB and then decreased abruptly with fruit ripening, reaching a final level of about 26.44N on 160 DAFB. Starch content of fruit sap was also decreased abruptly after 146 DAFB which decreased almost half of the fruits harvested at 139 DAFB. In parallel with the decrease of flesh firmness, ethanol insoluble solids (EIS) content decreased sharply with fruit ripens, only 50% of EIS was detected on the fruits harvested on 160 DAFB when compared to that of the fruits harvested on 139 DAFB (Aug. 30). The maximum value of soluble solids contents was observed in the fruits harvested on 153 DAFB, resulting in 14.2Brix. The changes of skin color difference a* which means loss of green color occurred only after 139 DAFB, coincide with the decrease of SPAD value of the fruit skin. The sugars of the 80% ethanol soluble fraction consisted mainly of fructose, sorbitol, glucose and sucrose, also increased during maturation and ripening. Fructose and sucrose contents were larger than those of glucose and sorbitol in flesh tissues. These results were explained that stored starch is converted to soluble sugars during fruit maturation, mainly in fructose and sucrose increasing the sweetness of this cultivar. Total polyphenols were increased up to middle of fruit maturation (146 DAFB) and then decreased continuously until the end of fruit maturation. Consequently, our results suggested that the commercial harvest time of ‘Changjo’ pears should not be passed 153 DAFB and late harvest of this cultivar would not good for quality maintenance during shelf-life. As a result of the post-harvest low-temperature acclimation experiment during the short-term transportation period, fruits harvested at 146 DAFB tended to maintain higher firmness after 14 days of simulated marketing at 25C compared to fruits harvested at 153 DAFB regardless of temperature set. And, the slower the rate of decrease to the final transport temperature of 5C, the higher the incidence of internal browning and ethylene production. Therefore, in order to suppress the physiological disorder and to maintain the fruit quality when exporting to Southeast Asia in the ‘Chanjo’ pears, it is desirable to lower the temperature of the fruits within a short time after harvest and to set the harvest time before 146 days after full bloom. Additional key words : ethylene, firmness, respiration, ripening, soluble solids *Corresponding author: jpchun@cnu.ac.kr *Received June 02, 2017; Revised September 13, 2017; *Accepted October 12, 2017 이욱용 · 최진호 · 안영직 · 천종필 379 Protected Horticulture and Plant Factory, Vol. 26, No. 4, 2017 서 론 배 ‘창조’는 국립원예특작과학원에서 1995년 ‘수진조 생’에 ‘81-1-27’을 교배하여 2009년에 최종 선발한 품종 으로 검은무늬병에 저항성이며 성숙과의 과중은 700g 내외, 당도는 13Brix로 식미가 매우 우수하다. 평균 숙 기는 10월 2일(수원지방 기준)로 ‘신고’ 보다 10일 정도 빨라 추석이 조기에 도래할 때 유통이 가능하다는 점에 서 유망 품종으로 대두되고 있다(Shin 등, 2011). 과실의 성숙시기 즉 수확 시기는 유통 중 품질유지 및 생리장해 발생에 결정적인 영향을 미친다. Jeong 등 (1998)과 Hong 등(2004)은 품종과 과실의 성숙도에 따 라 호흡 특성이 달라지고 호흡 특성과 관계없이 미숙기 에 수확한 과실이 상온에서 보관된 것보다 저온 및 CA 조건에서 더 오래 저장되므로 각 품종별 수확시기 및 보관방법을 결정하는 것이 매우 중요하다고 하였다(Kim 등, 2002; Kim 등, 2003; Kim 등, 2007). 배 과실의 수 확시기 결정 요인에는 과피색의 변화, 과육 경도, 호흡 량 등의 지표를 이용할 수 있으며 적정한 시기에 수확 한 과실은 상온, 또는 고온 유통 중 급격한 품질 악화를 줄일 수 있는 것으로 보고된 바 있다(Lee와 Chun, 2011; Lee 등, 2011; Oanh 등, 2012). 그러나, 최근 농 가에 보급 중인 ‘창조’ 품종은 성숙생리 및 수확 후 생 리 변화에 대한 보고가 없다. 온도는 원예산물의 수확 후 품질변화를 좌우하는 주요 요인이다(Brosnan과 Sun, 2001), 즉, 온도는 수확 후 과 실의 품질 변화 항목 중 과실의 호흡량과 밀접한 관련 이 있다. 품온이 높은 상태에서 수확된 과실의 온도관리 는 상품성 유지에 매우 중요한 요소이다(Bachmann과 Earles, 2000). 사과에 있어서는 지연냉각을 통해서 장기 저장 한 사과의 생리장해 경감 효과가 보고된 바 있다 (DeLong 등, 2004). 동양배에 있어서도 유통 온도에 따 른 호흡량 및 에틸렌 생합성과 같은 생리적 변화가 다 르게 나타나므로(Lee 등, 2017), 과실품질의 변화를 늦 추기 위해서는 수확 이후 저온조건에서 과실의 호흡량을 낮추는 조치가 필요하다(Oh 등, 2010). 이에 본 실험은 ‘창조’ (‘수진조생’ × ‘81-1-27’) 배의 성숙 및 연화생리를 이해하는 기초자료로 제공하고 단기 수출과정에서의 과실 품질 변화를 지연 시킬 수 있는 수송온도 설정 방법을 연구하여 고품질 국내 육성 배의 생산 및 수출물량 확대에 기여하고자 실시하였다.

국내에서 육성된 중생종 동양배 품종인 ‘창조’는 성숙 기간 중 지속적으로 과실이 비대하여 600g대의 편원형 과실로 발달하였다. 성숙기간 중 경도는 경시적으로 저 하되어 만개 후 153일인 9월 13일에 32.58N으로 조사 되었고 만개 후 160일에는 26.44N으로 급격히 경도가 저하되었다. 식감과 관련된 품질요인 중 과실의 전분함 량은 만개 후 153일에 0.737, 만개 후 160일에 0.451로 전분함량이 급속히 감소하였고, 과육의 세포벽함량을 조 사하였던 결과, 과실비대가 증가하고 과실성숙의 진행과 더불어 알코올불용성물질 함량은 낮아지는 경향을 보였 다. 과피색차 중 적색도(a*)는 만개 후 139일 이후 양의 값을 보여 외관상의 과피녹색 발현이 소실되었는데 과피 의 SPAD 값을 조사한 결과에서도 동일하게 엽록소의 감소를 확인할 수 있었다. Hue angle 역시 성숙과 연화 기간 중 유의하게 감소하는 경향을 보여 수확시기의 지 표로 활용 가능하다고 판단되었다. 성숙기간 중 과육 내 에 축적되는 당 성분을 분석한 결과, 만개 후 153일에 총량이 최대치를 보였는데 전 생육시기에 걸쳐 전체 당 성분 중 과당이 우점하고 있었고, 과실성숙도가 높아질 수록 자당의 비율이 유의하게 증가하여 만개 후 160일 에 수확한 과실에서는 자당이 과당을 넘어 우점하여 과 숙단계로 생각되었다. 따라서, 배 신품종 ‘창조’의 적정 수확시기는 만개 후 153일인 9월 13일 이전으로 평가되 었고 수확시기를 놓친 경우에는 경도 등 과실의 품질이 급격하게 하락하는 것으로 사료되었다. 대만 지역 수출 을 모의하여 단기수송온도 설정을 위한 수확 후 저온순 화 실험을 실시한 결과, 만개 후 146일에 수확한 과실이 만개 후 153일에 수확한 과실에 비하여 25°C 유통 후 높은 경도를 유지하는 경향을 보였고 최종 수송 목표 온도인 5°C로 저하되는 속도가 느릴수록 과육장해의 발 생심도 및 에틸렌발생량이 높은 경향을 보였으므로 ‘창 조’ 품종에 있어 동남아 지역 수출 시 생리장해 및 과실 품질 유지를 위해서는 수확시기를 만개 후 146일 이전 에 설정하는 것이 바람직할 것으로 판단되었다. 본 연구 결과를 바탕으로 ‘창조’ 배의 목적별 수확시기 결정 및 과실의 선별 기술에 일조하고 수출 시장에서의 한국산 배의 신인도 확보에 기여할 것으로 기대된다.

This study was conducted to explore which pollen type could be an effective pollen source for self-incompatible ‘Niitaka’ pear (Pyrus pyrifolia Nakai), when different pollinizers were to be applied. The pollens of five different pears with similar flowering times were applied to bagged ‘Niitaka’ flowers grown in Cheonan city, Korea. Pollen types used were of different origins including Korean pears (‘Wonhwang’ and ‘Chuhwangbae’), Japanese pears (‘Chojuuro’ and ‘Okusankichi’), and Chinese pear (‘Yali’). Results show that the amount of pollen produced by flowers of each cultivar was the largest in Korean pear ‘Wonhwang’ (234 g/100 flowers) and the smallest in Japanese pear ‘Okusankichi’ (126g/100 flowers). A high proportion of large fruits (> 600 g), 71.4% of total production, was found in the fruits treated with ‘Yali’ pollen. However, these fruits showed an unfavorable external appearance. Based on individual fruit width differences, ‘Chojuuro’ treatment produced the smallest difference in fruit diameters (3.2 mm) and ‘Yali’ treatment’ gave the largest (4.8 mm). Also, the difference in fruit length was the largest in ‘Yali’ (7.5 mm), which also produced the most uneven fruits among the pollinizers used. Meanwhile, the use of pollens of ‘Wonhwang’ and ‘Chuhwangbae’ improved productivity by increasing the fruit shape index and the ratio of bigger fruits in total production. Moreover, those pollens also decreased the development of lenticels on fruit skins which gave them a smoother appearance.

The purpose of this study was to establish postharvest management techniques including a temperature pre-conditioning protocol for maintaining fruit quality in newly developed early season Korean pear cultivar 'Hanareum' (Pyrus pyrifolia Nakai). The fruits were treated with three different pre-conditioning temperatures (21, 25, or 29 degrees C) for 4 days according to the harvest time (103 or 110 days after full bloom, DAFB). The percent weight loss was relatively low in the fruits subjected to low pre-conditioning temperature regardless of harvest time. The firmness of the fruits treated with pre-conditioning at 21 degrees C remained high during 20 days of simulated marketing at 25 degrees C, although all treated fruits showed a general decline of firmness with extended time of simulated marketing. These fruits also showed higher appearance and a lower incidence of mealiness disorder symptoms. During the experimental periods, the production of ethylene was lower in the fruits pre-conditioned at 21 degrees C in comparison with those of treated at 25 and 29 degrees C. High respiration rates were obvious in the fruits pre-conditioned at high temperature (29 degrees C), especially in the optimum-harvested fruits, where respiration was approximately two times higher than that of fruits exposed to 21 degrees C during pre-conditioning. However, the respiration rate was similar during simulated marketing at 25 degrees C regardless of harvest time. These results demonstrated that temperature pre-conditioning at 21 degrees C is a simple and effective postharvest technique for summer harvested Korean pear cultivars including 'Hanareum'.

We investigated the effect of preharvest spray of aminoethoxyvinylglycine (AVG) on the fruit quality and incidence of physiological disorders during shelf-life of 'Hanareum' and 'Wonhwang' pear (Pyrus pyrifolia Nakai). AVG applications (0, 75, 150 and ) made 30 days before anticipated harvest of respective cultivar. AVG did not influence the fruit development and quality parameters including starch content, soluble solids and acidity at harvest time in two pear cultivars although the flesh firmness of the fruits treated with AVG were higher than that of control in 'Hanareum' pear. Among the three AVG concentrations, only AVG showed effectiveness on maintaining flesh firmness in 'Hanareum' pear during shelf-life. Meanwhile, competitive high flesh firmness was attained in 'Wonhwang' pear treated with AVG (27.7 N) and AVG (28.2 N) when compared with untreated control (17.8 N) during 21 days of shelf-life at . AVG did not cause any significant difference at skin color development relative to control in two pear cultivars. AVG decreased ethylene production and respiration rate at level in two pear cultivars during the entire shelf-life. During shelf-life, low incidence of physiological disorders including internal and core browning and mealiness were attained in the fruits treated at AVG in two cultivars when we compared with the untreated control.

We investigate the effect of preharvest spray of aminoethoxyvinylglycine (AVG), an inhibitor of ACC synthase activity, on fruit quality of 'Wonhwang' pear (Pyrus pyrifolia Nakai). And the effects were compared with ethephon which releasing ethylene to elucidate treatment efficacy of ethylene biosynthesis inhibitor on Asian pears. Chemicals were sprayed on 30 days before harvest with AVG (75 and 150 mg/L) and ethephon (100 mg/L), respectively. Highest flesh firmness during 21 days of shelf-life at $25^{\circ}C$ after 30 days of cold storage was attained in the fruit treated with 150 mg/L AVG (26.5N) when compared with untreated control (16.7N), while the fruits treated with 100 mg/L ethephon completely lost their marketability within 14 days of shelf-life by mass drop of firmness down to 11.6N. Low incidence of physiological disorders including pithiness and core browning were attained at the fruits treated with 150 mg/L AVG when we compared with untreated control. No occurrence of mealiness found in the fruits treated with AVG but ethephon treated fruits showed 36.4% during 14 days of shelf-life. Consequently, AVG spray at the concentration of 150mg/L on Asian pear 'Wonhwang' fruit regarded as useful preharvest management approach for keeping quality during marketing period after simulated exportation.

: We tested fruits quality and skin coloration of two pear cultivar ‘Wonhwang’ and ‘Whasan’ produced by bagging with different kinds of paper bags in the Cheonan area, Chungnam Province, Korea. The fruits were bagged at 35, 45, 55 or 65 days after full bloom (DAFB) with 3 kinds of double layer paper bag which consisted of grey color, yellow color and newspaper for outer layer. The great extent of light interruption was observed in grey colored outer paperbag among three kinds of paperbag which showed only 0.46% of lowest light transmittance when compared with 43.7% and 40.0% of yellow paper and newspaper, respectively. The development of skin redness (a*) increased with the delay of bagging time in two pear cultivars. But the fruits treated at 65 DAFB showed uneven coloration and excessive development of redness which represented low fruit external appearance value. Uniform flesh firmness was attained at the fruits bagged with grey outer color paperbag regardless of bagging time, although the fruit quality indices including soluble solids and titratable acidity did not change significantly by using different kind of fruit bags and bagging time in two pear cultivar. Based on our results, it was explained that the grey-colored fruit bag had positive effect on the development of skin coloration without any detrimental effect on fruit quality factors in ‘Wonhwang’ and ‘Whasan’ pears.

This study was conducted to investigate the effect of temperature during transportation and continuing shelf-life on fruit quality and the occurrence of physiological disorder to set up the appropriate exportation temperature condition in Asian pear (Pyrus pyrifolia Nakai) 'Hanareum'. In the experiment of simulated exportation headed for USA, the fruits transported at $1^{\circ}C$ showed less weight loss than those of $5^{\circ}C$. Market temperature appeared as a key factor for keeping freshness of exported pear fruits rather than transportation temperature. Quality factors such as high flesh firmness and low incidence of fruit rot and physiological disorders including core breakdown and pithiness were attained at the fruits maintained at $18^{\circ}C$. Approximately two times higher incidence of physiological disorders and of fruit decay rates were observed in the fruits distributed at $25^{\circ}C$ than the those of $18^{\circ}C$. Therefore, temperature management during marketing resulted as an important factor for maintaining fruits quality in the process of pear fruit exportation.