• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.271-276
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• 2015

Crab apple cultivars, 'Maypole', 'Tuscan', and 'Manchurian', were evaluated as potential pollinizers of major apple cultivars, 'Fuji', 'Hongro', and 'Tsugaru', cultivated in high-density apple orchard systems. Numerous cultivar characteristics, including blooming time, pollen germination, fruit set, disease and pest resistance, and self-incompatibility, were examined. The blooming times of both 'Maypole' and 'Tuscan' ranged from April 19 to May 5, which was 2-4 days earlier than those of the major commercial apple cultivars. PCR analysis did not reveal the presence of any of the S-alleles (S1, S3, S7, or S9) identified in major commercial apple cultivars. In addition, the percentage of the fruit set was high after trees were artificially fertilized with crab apple pollen. Artificially cross-pollinated fruits were of similar or higher quality than open-pollinated fruits. They also demonstrated resistance to apple blotch, sooty blotch, and fly speck. The results indicate that the two crab apples, 'Maypole' and 'Tuscan' would be potential candidates for pollinizers of major apple cultivars in Korea. Use of the pollen of these crap apples in commercial production will improve fruit quality and promote sustainable and robust fruit production.

• Journal of Agricultural Extension & Community Development
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• v.4 no.2
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• pp.423-429
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• 1997

Under the WTO system in the world, our country's apple industry must be set in quite a new aspect. For new apple industry with competition power, we should establish apple industry development strategies as follows. First, to change the present apple trees to the lowered or dwarf tree with high density planting system using M9 rootstocks. Second, to expand the size of apple orchard management and to bring up as professional apple farmers. Third, to develop the integrated apple production system considering environment and human being. Fourth, to innovate improved harvest, storage and shipment system. Finally, Rural Extension Institution should activate the farmer's training and produce the apple nursery trees of better quality.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.165-170
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• 2004

This study was conducted to investigate the effect of different surface soil management practices on soil microflora in volcanic ash soils of citrus orchard. Soil samples were collected from citrus orchards of clean cultivation, grass sod, and grass mulch system in May and September 1997. Soil chemical properties, populations of various microorganisms, enzyme activities, microbial biomass C were analyzed. Average soil pH were 4.7, and average nitrogen and organic matter contents were 6 and $140.2g\;kg^{-1}$, respectively. Aerobic bacteria were distributed at $26,2-47.3{\times}10^6cfu\;g^{-1}$ level. Among the aerobic bacteria Pseudomonas spp., Rhizobium spp., and thermophilic Bacillus spp. were dominant in most of the investigated orchard soils. Density of actinomycetes were low at $1.8-84.6{\times}10^5cfu\;g^{-1}$ level. Fungi were distributed at $26.4-182.1{\times}10^5cfu\;g^{-1}$ level and the density was higher in grass mulch and sward sites. In september, phosphomonoesterase activity was high at $239.6{\mu}g\;PNP\;g\;soil^{-1}\;h^{-1}$ in clean cultivated citrus orchards. Soil cellulase activity were higher at $602.6{\mu}g\;GE\;g\;soil^{-1}$\;24\;h^{-1}$ in grass sward cultivation than any other soil management practices. Soil microbial biomass C was higher in grass mulch cultivated orchards.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.405-411
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• 2007

This study was carried out to measure insoluble phosphorus fractions content fixed in different soil type and isolate a superior phosphate solublizing bacteria(PSB) producing free phosphate in citrus orchard soil. Distribution of insoluble phosphate fraction ordered Al-P>Ca-P>Fe-P in the investigated citrus orchards. Insoluble phosphate fraction such as Al-P, Ca-P, Fe-P were higher in volcanic ash than in non-volcanic ash soil. A PSB with high holo zone in PDA-P medium isolated from citrus orchard soil. This strain identificated by MIDI system as Bacillus sphaericus. The optimum growth of pH and temperature were at 4~5, $30^{\circ}C$, respectively. When Bacillus sphaericus cultured at $25^{\circ}C$, 150 rpm condition in LB broth medium included different phosphate. Bacillus sphaericus produced free phosphate in the culture broth medium from tricalcium-phosphate(207.0 ppm), aluminium phosphate(324.5 ppm) and hydroxyapatite(334.8 ppm) and Phosphatase activity of Bacillus sphaericus was higher at $35^{\circ}C$ culture condition than that of $25^{\circ}C$. Two type preparation inoculated Bacillus sphaericus made with carrier materials such as Bentonite, $CaCO_3$, Sodium alginate. Density of PSB in this preparation conserved at $10^5c.f.u.\;g^{-1}$ level during storage in different temperature condition for 7 month. It also showed that free phosphate produced at PDA-P medium.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.228-237
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• 2003

Temporary control schedules were tested at sweet persimmon orchards to development new control programs to meet the quarantine repuirements of America in 2001 and 2002. The 'MRL-type control orchards' were sprayed with chemicals which were possibly adaptable to the pome trees in America. A control schedule consisted of those chemicals registered for persimmon in Korea was incorporated in the 'domestic-type control orchards'. The efficacy of these two control type against insect pests was compared with that of a conventional control schedule. In 2001, MRL orchard and domestic orchard were sprayed 7 and 6 times, and two conventional orchards were 6 and 9 times, respectively. In 2002, acaricide was added once to the MRL orchards at late September to reduce the density of mites on harvested fruits. However no insecticide to plant bug control could be applied to the MRL orchards, because no insecticide against bugs was registered for pome trees in America. This resulted in 7 times of applications in MRL and domestic orchards. The conventional orchard was sprayed 9 times. Only the occurrence of the peach pyralid moth, Dichocrocis puntiferalis (PPM) out of 4 quarantine inset species was observed. The PPM was observed during growing season in MRL, domestic, and conventional orchards. However no fruits damaged by PPM larvae were observed after mid October and after harvest. In 2002 only 1 fruit out of 1,350 fruits inspected in June was damaged by the larvae of PPM at MRL orchards. A fungus-feeding mites and collembolan were under calyx of vested fruits. In 2001 they were found on 45.3% of harvested fruits at MRL orchard. However the percentage of fruits with mites in 2002 was greatly reduced to 3.5% at MRL orchard, presumably because of a added application of acaricide at late September. However percentage of fruits damage by hemipteran bugs at harvesting time was quite high 11.3 % at MRL orchards, because no application of insecticide against plant bugs.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.173-176
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• 2016

This research was performed to breed new columnar-typed apple variety for pollinator in apple orchard. We cross-fertilized 'Hongro' that was an ovary parent and 'Maypole' a pollen parent in 2003. We gathered seeds in 2003 and sowed after breaking of dormancy in 2004. Seedlings was been growth and development till flowering. After fruit setting, We investigated characteristics of growth and fruit including mating compatibility from 2010 to 2012, then finally selected '03-2-95' named 'Tinkerbell' in 2012, registered as new variety on Korea Seed & Variety Service in 2015. The full bloom stage of 'Tinkerbell' was later 2 days then of 'Maypole'. Tree habit of 'Tinkerbell' was alike to of 'Maypole', for example weak tree vigor, columnar type. But there were many different characteristics between 'Tinkerbell' and 'Maypole'. Fruit shape of 'Tinkerbell' was ovoid whereas of 'Maypole' was ellipsoid. Fruit of 'Tinkerbell' was bigger, smoother skin, no waxy bloom than of 'Maypole'. Fruit of 'Tinkerbell' was more delicious than of 'Maypole' because of having higher soluble sugar content and lower titratable acidity. 'Tinkerbell' was excellent pollinator in apple orchard. Because of having high fruit setting rate with major apple varieties and a narrow tree width that was advantageous as pollinator in apple high density system.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.115-123
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• 2005

Historical changes of population abundances of European red mite (ERM), Panonychus ulmi (Koch), and two-spotted spider mite (TSSM), Tetranychus urticae (Koch) (Acari: Tetranychidae), were described in selected apple orchards in the National Horticultural Research Institute (NHRI, Suwon, Korea), based on research reports of the NHRI from 1958 to 1998. ERM was an abundant species up to 1970, and TSSM became a dominant species after 1980. The change occurred around mid 1970. Three hypotheses were made to explain the change: TSSM competitively replaces ERM, ground cover weeds are a major influencing factor on movement of TSSM (TSSM movement into trees is accelerated by destroying weeds), and ERM and TSSM populations are regulated by natural enemy complexes when the orchard system is not disrupted. And long-term results of the interaction between two species were projected according to the combination of different orchard management strategies: pesticide sprays (non-selective toxic pesticide spray : heavy pesticide pressure (HPP), and selective soft pesticide spray = low pesticide pressure (LPP)) and weed control methods (grass planting, and clean culture system with herbicides). In the HPP and grass planting system, ERMs are abundant because ERM can avoid competition with TSSM as movement of TSSM to trees are restricted, and natural enemy complexes are destroyed by toxic pesticides. In the HPP and clean culture system, TSSMs are abundant because TSSM moves to trees from early season and competitively replaces ERM. In the LPP and grass planting system, ERMs are abundant because movement of TSSM to trees is reduced, but they do not build up a high population density since their densities are regulated by natural enemy complexes. In the LPP and clean culture system, TSSM moves to trees and competes with ERM, but the competition pressure is reduced because population densities of mites are regulated in a lower level by natural enemy complexes. So, ERM can occurs in late season. Thus, two species can coexist temporarily with more ERM in early season and more TSSM in late season. TSSM abundant phenomenon presented in this study can be partially explained as a result of long-term interaction between ERM and TSSM under the HPP and clean culture system.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.393-401
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• 2017

One-year old pear (Pyrus pyrifolia L.) trees of a new commercial cultivar 'Manpungbae', recently developed in South Korea, were planted in 2001 (planting year 1) and trained to four trellis systems: Y-trellis, Y-II-trellis, pergola, and vase-pergola. To evaluate training systems in the local area (southern Korea), tree growth responses were compared for each trellis system from planting years 3 to 8. For trees trained to Y-trellis and pergola systems, a high proportion of land covered by tree canopy was maintained over the study duration, with 70-80% coverage in year 8. Eight-year cumulative yield per tree was increased in the vase-pergola system with a low planting density and an additional scaffold. Compared with other systems, cummulative yield use efficiency was greatest in Y-II-trellis and pergola systems in years 5 and 8. Compared with Y-II-trellis and vase-pergola systems, the 8-year cumulative yield per hectare was two fold greater for trees trained to the Y-trellis (103 tons) and pergola systems (101 tons). Use of the pergola system improved average fruit weight and fruit soluble solid contents, as well as net income in year 8. Given that we observed reduced fruit productivity and increased labor hours (pruning and orchard work), we consider the Y-trellis and pergola systems to be less valuable trellis systems than the others evaluated.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.374-380
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• 2010

Well-feathered (5.2 feathers, stem diameter 13 mm) trees of 'Fuji' apple/ M.9 EMLA were planted at $4.0{\tiems}1.5$ m and whip trees (stem diameter 10 mm) of 'Fuji'/M.26 at $4.0{\times}2.0$ m were trained to the slender spindle. The productivity and yield efficiency of two orchard systems were compared for 6 years. The canopy volume of the tree/M.9 EMLA reached $2.07m^3$ in 2nd year and increased slowly to almost the targeted tree volume of $2.9m^3$ in 4th year. Trees/M.26 grew slowly at the begin but from 3rd year the tree volume expanded quickly to reach $5.6m^3$ in 5th year, covering over the allowed space. Yield of M.9 EMLA per 10a increased from 0.3 ton in 2nd year to 4.6 ton in 5th year, and 5.0 ton in 6th year, but yield of M.26 per 10a increased from 0.5 ton in 3rd to 2.9 ton in 6th year. Cumulative yield per 10a up to 6th year was 13.9 ton for M.9 EMLA but only 9.8 ton for M.26. Fruit weight for M.9 EMLA was heavier than that for M.26. In conclusion, the high density planting system with well-feathered trees/M.9 EMLA was better than the conventional wide planting system with whip trees/M.26.