• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.225-232
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• 2003

Nutrients and water absorption by Citrus unshiu Marc. cv. Miyagawa Wase were examined using spray type of out-door hydroponics system. Three different concentration levels of nutrient solution were treated to citrus trees to examine nutrient uptake. To do so, concentration and the volume change of nutrient solution was measured for each treatment. By weighing the volume of solution and citrus trees, amounts of water uptake and fresh weight increase were observed periodically. Water uptake by trees increased as tree grew and time elapsed, but was lower at high level of nutrient concentration than the rest, due partly to the reduction in hydraulic conductance and to the sustained high salt concentration. Rapid increase in fresh weight and nutrient uptake occurred from May to July and from August to September. The amounts of nutrient uptake were significantly different among nutrient levels: the higher concentration, the greater uptake by citrus tree. The absorbed amounts of $NO_3$, K and Ca were much higher than those of $NH_4$, S, P, Mg, and Fe. Most mineral contents in leaves were proportional to the concentration of supplied nutrient solutions. From the results of nutrient absorption and contents in leaves at different levels of nutrient solutions, the composition of major elements for citrus nutrient solution can be modified as follows: 27.1, 16.5, 66.0, 80.0, and $24.0mg\;L^{-1}$ for N, P, K, Ca, and Mg, respectively.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.390-395
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• 2015

The synthesis of chimeras is a breeding approach for horticultural crops. In our breeding program, a new diploid citrus chimera, named 'Hongrou Taoye' (Citrus sinensis [L.] Osbeck + Citrus unshiu Marc.), was found arising at the junction where a 'Taoye' sweet orange (C. sinensis) scion was grafted onto Satsuma mandarin (C. unshiu). As an artificial chimera, its fruit traits derived from the L1 cell layer, with juice color and carotenoid complement, in which ${\beta}$-cryptoxanthin accumulated predominantly, similar to those of Satsuma mandarin. By contrast, traits originating from the L2/L3 cell layer, including pollen, seed, and rind aroma characteristics, were the same as those of 'Taoye' sweet orange (the scion). SSR and cpSSR analyses showed that both nuclear and chloroplast genomes of the chimera were a combination of both donor parents. 'Hongrou Taoye' thus combined the valuable traits of both donor plants, and therefore has good potential in citrus fresh market.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.514-516
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• 1998

This study was conducted to observe the effects of urea foliar spray to replace soil fertilization on defoliation ratio, shoot growth and fruit setting in satsuma mandarin (Citrus unshiu Marc.). Twice foliar sprays of 1% urea after harvest increased N and chlorophyll contents in leaves, and decreased defoliation during the winter season. The growth of the ovary and spring shoot was stimulated by the twice 0.8% urea foliar spray around the time of bud emergence. In addition, the treatments increased the number of flowers and fruit setting, but didn't influence fruit quality.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.405.1-405.1
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• 2002

The amount of water for the cultivation of citrus is different based on the growing period. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine non-destructively the water content of Citrus leaves by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from satsuma mandarin leaves (Citrus unshiu Marc. var. okitsu) ranging from 62.20 to 69.98% of water content by loss on drying, NIR reflectance spectra of Citrus leaves were acquired by using a fiber optic probe. (omitted)

• Food Science and Preservation
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• v.7 no.1
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• pp.44-50
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• 2000

Physicochemical properties and sensory evaluation of Satsuma mandarin produced in Cheju were investigated . Fruit index(width/Length), soluble solids and acid content of Citrus unshiu marc. var. miyagawa(miyagawa) and C. unshiu marc. var.(okitsu) harvested at 1st December were 1.16 and 1.23, 12.12 and 12.01, 0.97 and 1.09, respectively. and the fruit of miyagawa was showed somewhat round in shape, compared to ikitsu. the taste of miyagawa seemed to be better than okitsu. However, compared to miyagawa, peel thickness was thinner, flesh ratio was higher, and firmness was higher as 0.502kg-force in kitsu. Nevertheless there were some differences among panelist groups in sensory evaluation , middle size of citrus fruits were favorable to most panelists, but except very small or very large size of fruits, there were not so much differences in okitsu. The panelists referred to somewhat flat-shaped fruits from that sensory evaluation score was increased to 1.3 in fruit index. nevertheless there were not so much differences in full-colored fruits, the citrus peel color of reddish yellow was more favorable than greenish or pale yellow color. the score was increased more linearly according to citrusfruit produced in optimum ciltivation area, and was prefered to thinner in peel thickness , Correlation between soluble solids, acid content , Brix/acid ratio and flesh ratio with sensory evaluation score were not showed significantly, it was different to with citrus juice. This data obtained in this experiments are supposed to be applied to the quality evaluation of Satsuma mandarin produced in Cheju .

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.184-187
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• 2008

A new early maturing satsuma mandarin (Citrus unshiu Marc.) 'Haryejosaeng' was developed as a nucellar seedling selection of 'Tachima Wase' (C. unshiu Marc.) that was crossed with C. natsudaidai Hayata at the National Institute of Subtropical Agriculture in Jeju island in 1992. The 'Jegam ga No. 2', a first selection from the seedlings fruited in 2001 was finally named "Haryejosaeng" through field evaluation trials at three locations in Jeju island from 2003 to 2004. 'Haryejosaeng' produces seedless fruit maturing in early November, and has higher soluble solids and lower acidity than 'Miyagawa Wase', the leading early-maturing satsuma mandarin cultivar in Jeju island. Fruit weight is moderate at about 80~90 g and its shape is compressed-oblate globose with a light orange color. The rind thickness of about 2 mm provides easy peeling. The flesh shows light orange colored and contains 10 to 11 Brix and 1 to 1.1% acidity when mature. Tree shows vigorous growth and spreading thornless twigs. Alternate bearing is similar to 'Miyagawa Wase'. 'Haryejosaeng' is susceptible to citrus scab disease and melanose, but resistant to citrus canker.

• Food Science and Preservation
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• v.5 no.1
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• pp.1-6
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• 1998

Physicochemical properties of early cultivar of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) according to harvesting year during 1990 to 1995 were investigated. Climatic conditions of every year affected the quality of citrus fruits. Compared to other harvesting years, flesh ratio and soluble solids were higher, but acid content was lower on citrus fruits produced in 1994, as for good climatic conditions during growth of fruits. Especially, acid content of fruits produced in 1993 was higher, compared to those of years, as for low mean temperature and high rainfalls. Fruit weight, peel thickness and soluble solids had a good linear correlation to fruits size, but acid content and flesh ratio had not correlation derived from difference of individual fruits. From the climatic data, the prediction of fruit quality would be possible in some degree before harvest. It seemed recommend to ably the flexibe method by harvesting year for the quality stanardization of citrus fruit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1233-1238
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• 2016

Combined treatment of chlorine dioxide ($ClO_2$) gas, mild heat, and fumaric acid was performed to reduce microbial growth and maintain quality of Citrus unshiu during storage at $4^{\circ}C$. Citrus unshiu fruits were treated with $ClO_2$ gas (15 or 30 ppmv), mild heat (40, 50, or $60^{\circ}C$), and fumaric acid (0.1, 0.3, or 0.5%). Combined treatment of 15 or 30 ppmv $ClO_2$ gas, $50^{\circ}C$ mild heat, and 0.5% fumaric acid reduced populations of inoculated Listeria monocytogenes by 3.5~3.7 log CFU/g. In addition, combined treatment decreased populations of yeast and molds in Citrus unshiu by 2.54 log CFU/g after 30-day storage at $4^{\circ}C$. Combined treatment also reduced the decay rate by 48% after 30 days of storage compared with the control. Total solid content, titratable acidity, and color values were not significantly affected by the combined treatment. Therefore, combined treatment of $ClO_2$ gas, mild heat, and fumaric acid can be a useful hurdle technology to improve microbial safety and quality of Citrus unshiu during storage.

• Analytical Science and Technology
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• v.16 no.4
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• pp.277-282
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• 2003

The amount of water for the cultivation of citrus is different based on the growing period. The effect of water stress induces to enhance of sugar accumulation in citrus. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine the water content of citrus leaves non-destructively by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from 'Okitsu' Satusuma mandarin leaves (Citrus unshiu Marc.) ranging from 20.80 to 69.98% of water content by loss on drying method, and NIR reflectance spectra of citrus leaves were acquired by using a fiber optic probe. It was found that the variation of absorbance band 1450 nm from OH vibration of water depending on the water content change. Partial least squares regression (PLSR) was applied to develop a calibration model over the spectral range 1100-1700 nm. The calibration model predicted the water content for the validation set with a standard errors of prediction (SEP) of 0.97%. In order to validate the developed calibration model, routine analyses were performed using independently prepared citrus leaves. The NIR routine analyses showed good results with those of loss on drying method with a SEP of 0.81%. The rapid and non-destructive determination of the water content in citrus leaves was successfully performed by portable NIR system.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.117-122
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• 1997

The conditions of cold storage of Citrus unshiu Marc. var. miyagawa produced in Cheju were investigated. Compared to the citrus fruits stored at room temperature, the content of soluble solids, total sugar, vitamin C and specific gravity decreased slightly on the fruits stored at $4^{\circ}C$ and 87% relative humidity. Decay ratio and weight loss were below 10% on keeping freshness relatively till late of March during cold storage. Weight loss, decrease of firmness and soluble solids occured gradually during cold storage. Nevertheless seal-packaging with 0.02 mm LDPE film or wax-coating of citrus fruits were effective on weight loss and appearance, decay ratio increased for long-term storage. It was needed to control humidity in cold chamber for preventing from decay and weight loss. Edible part ratio was decreased gradually by respiration, and peel and tissue of fruits were softened slightly by 60 days of cold storage. Decay ratio and weight loss of full-ripened citrus fruits were little during the storage for 100 days, compared to the fruits harvested early. Appearance and taste of citrus fruits stored for 4 month were good relatively, but decay occured rapidly on seal-packaging fruits putting out of cold room for a few days. Because of the difficulty of long-term storage for early variety of Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits.