• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.1
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• pp.59-71
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• 2014

This study was conducted to find out the freezing hardness of apple tree as influenced by dwarfrootstocks, cultivars, and low temperature treatments. The dwarf-rootstocks used were M.9 and M.26, and three cultivars used were early-maturing 'Tsugaru', mid-maturing 'Hongro', and late-maturing 'Fuji'. Chilling temperatures were applied from $0^{\circ}C$ to $-40^{\circ}C$. Checking points of apple tree for freezing hardness were rootstock, trunk, feather, floral bud and foliar bud. Investigations were evaluated by the measure of water loss, electrolyte leaching, and sprouting. The results did not show the differences in water loss, electrolyte leaching, and sprouting by dwarf-rootstocks. Water loss of 'Fuji' was lower than that of 'Tsugaru' and 'Hongro', but sprouting ratio of 'Fuji' was higher than that of 'Tsugaru' and 'Hongro'. Water loss and electrolyte leaching increased as treated by lower temperature, while sprouting ratio decreased. In $-35^{\circ}C$ treatment, sprouting of rootstock and trunk part were higher than that of feather, while sprouting of floral bud was lower than that of foliar bud. Sprouting of bourse shoot at the accumulated low temperature in terms of $-10^{\circ}C$ per day was 100% in the 28 days, and sharply decreased about 50% in the 35 days. In conclusion, there were no differences in freezing hardness between M.9 and M.26, but freezing hardness of late-maturing cultivar was tended to stronger than that of early-maturing and mid-maturing cultivars. Freezing hardness of floral bud was extremely weak $-30^{\circ}C$.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.27-33
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• 2020

To date, various kiwifruit cultivars have been developed and released. Asexual propagation by grafting onto seedlings rootstock have been widely utilized commercially in fruit trees including kiwifruit (Actinidia spp.). Most of commercial kiwifruit cultivars belong to A. chinensis and A. deliciosa. Recently, several cultivars were developed by interspecific hybridization with different species including A. arguta. There is a possibility for graft-incompatibility due to interspecific hybridization and therefore, we investigated graft-compatibility of newly released yellow-fleshed kiwifruit cultivars and a hybrid cultivar with various rootstocks of different species. The yellow-fleshed cultivars grafted onto same species, A. chinensis 'Kuimi', showed good shoot elongation, about 1 m in length 50 days after grafting. In contrast, the shoot elongation of the yellow-fleshed kiwifruit grafted onto different species was retarded. The shoot length of a hybrid cultivar (A. arguta × A. deliciosa) 'Skinny Green' grafted onto four different species was about 1 m in length, showing good graft compatibility with other species. Nevertheless, long term studies for graft compatibility of hybrid cultivars are still needed since graft-incompatibility between different species can occur several years later.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.25-30
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• 1993

The buds of Hayward/Bruno tree were damaged from $-7^{\circ}C$ but serious damage was found on the buds treated at $-15^{\circ}C$ and $19^{\circ}C$. The bark tissue was more suceptible to low temperature than the bud. The trees were survived and bursted their at all on the top of the graft union and new shoots were formed from the rootstock of the tree. Yellowish area on the leaf surface was found, which is believed that as a result of low temperature. From these, the kiwifruit trees must be grafted with cold tolerant rootstocks will be clarified in future.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.28-34
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• 2018

Yuzu (Citrus junos) gummosis disease, caused by Phytophthora nicotianae, was first reported in 1997. As known in citrus, Phytophthora is the most fastidious soil-borne pathogen to control. In order to minimize its damage to Citrus spp., integrated pest management (IPM) approach, including fungicide chemicals and resistant cultivars, is necessary. Therefore, in this study we tried to evaluate tolerance of yuzu cultivars and its related species against yuzu Phytophthora. Trifoliate orange was evaluated as a susceptible host to yuzu Phytophthora by both mycelial growth onto extract media and immature fruit inoculation. However, in zoospores spray-inoculation on 2-year-old cuttings tree, trifoliate orange appeared to have a resistant property as showing less than 6% diseased leaf rate. Among yuzu cultivars only 'Namhae No. 1' appeared resistant property against both P. nicotianae and P. citrophthora. The 'Namhae No. 1' showed 5.7% and 10.6% diseased leaf ratio by P. nicotianae and P. citrophthora, respectively. Clearly, in order to reduce damages caused by two yuzu Phytophthora, we suggest that growers may utilize a trifoliate orange as a rootstock and 'Namhae No. 1' as a scion for fruit production.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.342-344
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• 2012

A new grafted cactus cultivar, called 'Hwangseon', Gymnocalycium mihanovichii, is a hybrid crossed between two orange color cultivars 'Geoseong' and 'Huhwang'. Mating was performed in the greenhouse of National Institute of Horticultural & Herbal Science (NIHHS) in 2005. The harvested seeds were sown at 100 mL volumetric flasks filled with 'Kyoto' medium. Seedling had been grafted into a young rootstock, Hylocereus trigonus, and cultured in vitro in 100 mL test tube for more than six months. After re-grafting and planting in the green house in 2006, their characteristics were evaluated three times until 2009. The new cultivar has a flat round shape and bright yellow skin color. In addition, it has 7 to 9 ribs with gray and straight spines on the body and produces an average of 12.3 offsets.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.119-124
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• 2003

An effective grafting method for jujube nursery trees was developed to shorten the operation time, improve the percentage of "takes" and shoot emergence, and form the better graft union. Out of 7 grafting methods the splice, modified scion Ono graft and the bark graft showed relatively short operation time during the grafting operation comparing to the modified rootstock Ono graft or the chip budding. Among these methods, the bark graft demonstrated 100% "takes", but the modified scion Ono graft or the standard Ono graft showed 58.3% of "takes". The percentages of the vegetative shoot emergence were 100% fir the bark graft, 70% f3r the modified scion Ono graft and lower emergence percent for the rest grafting methods. The union tissue formation for the modified scion Ono graft, the bark graft, or the whip-and-tongue graft was significantly larger than the standard Ono graft or the splice graft. In a close examination of the cross sectional areas of the graft union formation through the microscope, the bark graft was superior, the standard Ono graft was inferior and rest of the grafting methods were intermediate.ing methods were intermediate.

• Natural Product Sciences
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• v.11 no.2
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• pp.58-62
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• 2005

Pygmaeopremna herbacea (Roxb.) Mold. (Verbenaceae) is a small herb or sometimes an undershrub arising from a perennial rootstock. The dry roots are dark muddy brown in colour having root nodules. Its extensively developed roots are widely used in tribal medicine. They are used as an aphrodisiac and for the treatment of gout, rheumatism and ulcers. This study deals with the detailed pharmacognostical evaluation of the dried roots and root nodules of P. herbacea which includes macro and microscopic studies, determination of physicochemical parameters and chemoprofiling of the extract using HPTLC fingerprint profiles. It was observed that the roots consist of a well developed cortical region consisting of tangentially elongated thin walled parenchymatous cells and contain polygonal stone cells as well as compound starch grains. Also the pith was parenchymatous. The HPTLC fingerprint profile of the methanolic extract showed the presence of seven major bands. Such an analysis may thus be utilized in identifying P. herbacea and in differenciating it from other species which are similar to it or are used as its adultrants/substitutes under the same vernacular name of Bharangi.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.87-92
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• 2013

This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension ($10^6$ sporangia/ml). At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840) showed moderate resistance and two accessions (IT185446 and IT187904) were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.513-521
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• 2022

Our study was carried out to determine the control efficacy of sodium hypochlorite (NaOCl) for violet root rot caused by Helicobasidium mompa in apple. The experiment was conducted in the farm located at Chungbuk province in South Korea from 2014 to 2016. When infected apple trees were treated at least two or three times with 31.25 and 62.5 ml/l available chlorine content in NaOCl, it greatly increased the rooting of rootstock, and restored the tree crown density by 44.4-60.5%. In addition, the number of commercial fruit setting was increased by 54.3-64.5%, and the total starch content in shoots was significantly higher than other non-treated apple trees. However, the untreated disease control and thiophanate-methyl WP treated trees showed the symptom of dieback. Therefore, our results indicate that the drenching treatment of NaOCl with 31.25-62.5 ml/l available chlorine content more than two times from late fall to early spring could effectively control the violet root rot and recover tree vigor up to 60%.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.525-529
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• 2013

As most of citrus, shiranuhi mandarin ((Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata) mainly use the trifoliate orange (Poncirus trifoliata) as its rootstock which has dwarf and cold hardness in Korea. However, recently, scion root was observed in 'Shiranuhi' mandarin tree grafted onto the trifoliate orange. This study was carried out to find out effects of scion root occurrence on the fruit quality, flowering and yield of shiranuhi mandarin. For the experiment, we selected six farmers who have outbreak of scion root in their Shiranuhi mandarin orchards and surveyed the difference of fruit quality of shiranuhi mandarin hybrid between scion root and control (trifoliate orange root). In the results, flowering was severely decreased in scion root trees compared to control. As a result of survey of 174 Shiranuhi mandarins, 160 trees were proved to be scion root, and had less flowering. Fruiting of scion root also severely dropped compared to control and thus, yields of scion root (6.4 kg) reduced by 24% compared to control (26.7 kg). The fruit size, weight and soluble solid contents of scion root were significantly reduced, but there were no differences in acid contents and coloring of fruit. From the results, we concluded that scion root had negative influence on flowering, fruit size and the yields of Shrinanuhi mandarin hybrid.