• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.561-570
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• 2022

This study investigated the changes in planting environment and growing conditions of 'Arisoo' apple trees under shading net treatments. Apple tree canopies were fully covered with Blue (blue color net, mesh size: 4 mm × 5 mm), Black-A (black color net, mesh size: 4 mm × 5 mm), Black-B (black color net, mesh size: 5 mm × 6 mm), and uncovered trees were used as the control. Inside the tree canopies, the illuminance was observed as 100% (85.0 Klux) in the control, but it decreased to 75% (64.3 Klux) in the Blue, 73% (63.0 Klux) in the Black-A, and 77% (65.9 Klux) in the Black-B nets, respectively. The solar irradiance was observed as 755 w·m^-3 in the control, but it was decreased to 715 w·m^-3 in the Blue, 624 w·m^-3 in the Black-A, and 647 w·m^-3 in the Black-B nets, respectively. The average daily temperature was observed to be the highest in the Black-A net (31.8℃) while it was observed to be around 30.0℃ in the control, Blue, and Black-B nets. In addition, the average fruit surface temperature was observed to be the highest (39.4℃) in the control, but it was decreased to 38.1℃ in the Blue, 37.3℃ in the Black-A, and 39.0℃ in the Black-B nets. However, the average soil temperature, the shoot growth rate, and leaf SPAD values were not different in all the treatments. Fruit sunburn disorders were the highest in the control while it was observed to be lower in the fruits from trees covered with the shading nets. However, at harvest, the fruit quality parameters were not different in all the treatments. Overall, this study suggests that the apple trees covered with the shading nets reduced the illuminance, solar irradiance, fruit surface temperature, and fruit sunburn disorders. However, the shading nets did not affect tree growth and apple fruit quality.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.641-647
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• 2015

This study was conducted to select native ground cover plants for sod culture in an organic apple orchard by estimating the effect of three native ground cover plants, Glechoma hederacea, Thymus magnus, and Ixeris stolonifera, on the soil coverage, time-periodic weed occurrence, fruit characteristics, and soil chemical properties. The plant height of G. hederace, T. magnus and I. stolonifera were 15.0 ㎝, 13.4 ㎝ and 7.2 ㎝, respectively. The dry weight of G. hederace, T. magnus and I. stolonifera were 463 ㎏/10a, 247 ㎏/10a, and 255 ㎏/10a, respectively. The plant height and dry weight of G. hederacea were higher than in the other species. T. magnus and I. stolonifera having relatively lower soil cover rate during their life cycle produced a lot of weeds in the orchard as compared with the control. In contrast, G. hederacea showed 100 percentage of ground cover in the first year, and maintained high percentage of ground cover in the growing season of ‘Tsugaru’ apple for another 2 years. When the soil was covered with G. hederacea in the orchard for 3 years, the amount of weed was only 114 ㎏/10a and number of weeding was also reduced about 33% compared with control as well as the other species. There were no differences in the tree growth and fruit characteristics between the native ground cover plants and the control; however, positive effects of native ground cover plants on soil chemical properties were found. In G. hederacea, available P₂O₄content in soils remarkably increased and was a significant difference among native species. In addition, cation (Ca, Mg and K) content in soils increased by 39% in Ca, 6% in Mg, and 11% in K at G. hederacea compared with control. These results suggest that G. hederacea could be advantageous in terms of reducing the amount of herbicide applied and the labor required for weed control, and controlling soil chemical properties; therefore, it is a good candidate for sod culture in an organic apple orchard.

• Journal of Biosystems Engineering
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• v.34 no.6
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• pp.397-403
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• 2009

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.79-84
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• 2000

The aim of this study was to evaluate the chemical properties of orchard soils through which their soil fertilities were discriminated. Total 877 soil samples in major orchard area, i.e. from 239 apple, 369 pear, 168 grape, 101 peach orchards, were examed on the basis of temporary optimal range for each component. The levels of fertility were ranged from 3.0 to 65.2% compared to optimum fertility, suggesting that almost orchard soils contained inadequately soil components. The contents of chemical component have a tendency to decrease with soil depth gradually from surface to subsoil. This meaned that the contents of various components in subsoil could be estimated on the basis of analysis of surface soil, using the linearly fitted equations of the relationship between component in subsoil and in surface at least to which fertility were samely managed. Furthermore, even when only the content of components in 20cm depth surface soil was analyzed, it could be determined whether the amount of each component in the surface soil is surplus or deficient.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.383-387
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• 2004

Effects of oyster shell powder as a liming material were investigated in an apple orchard. Soil texture of the apple orchard was silty clay loam (Upyeong series with 7% of slope) and topsoil pH was 5.6. Treatments of 1,590 kg oyster shell powder $ha^{-1}$ and calcium-magnesium carbonate as much as oyster shell powder were included in the experiment. With treatments of oyster shell powder and calcium-magnesium carbonate, the length, number and diameter of new branches and the diameter of main, secondary and side branches increased in comparison with control. With oyster shell powder application, soil pH increased from 5.6 to 6.8 at the harvest. In addition, it increased exchangeable Ca from 2.6 to $4.2cmol_c\;kg^{-1}$. But it didn't make any difference in chlorophyll, sugar and malic acid contents. The apple weight per fruit of oyster shell powder application was 9 g more than that of control. Apple yield was highest ($37,000kg\;ha^{-1}$) in the oyster shell powder treatment, and the yield increase was significantly different at 5% level LSD. We concluded that the oyster shell powder can be an alternative of lime and effective to restore soil nutrient balance in apple orchard soil.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.90-90
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• 2004

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2000.05a
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• pp.61-61
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• 2000

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.83-89
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• 1998

The occurrence of postharvest disease of apple was surveyed from 1995 to 1997 in the major apple-producing area in Korea. Ten genera including Alternaria spp., Botryosphaeria dothidea, Botrytis cinerea, Fusarium spp., and Penicillium spp. were isolated from the decayed apple fruits. Of these, B. cinerea, Penicillium spp. and Fusarium spp. were frequently isolated and were highly pathogenic to apple fruits. Optimum temperature of mycelial growth for Penicillium spp. ranged from 10 to $30^{\circ}C$ and that of mycelial growth for B. cinerea and Alternaria spp. ranged from 5 to $30^{\circ}C$. Optimum temperature of sporulation of Penicillium spp. and Alternaria spp. ranged $15{\sim}25^{\circ}C$ and $10{\sim}20^{\circ}C$, respectively. Occurrence of postharvest disease of apple increased in neglecting selection of wounded fruits before storing apples. Most of these fungi causing postharvest diseases such as Penicillium spp, Botrytis cinerea and Alternaria spp. were isolated from healthy fruits sampled at apple orchard. These results suggested that posthavest diseases of apple were originated from apple fruits contaminated from apple orchard and occurred during storage. In addition, five fungicides including prochloraz EC, fenari EC, captan WP, benomyl WP and folpet WP suppressed posthavest diseases when they sprayed on apple fruits at 30 days before harvesting.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.298-303
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• 2013

In this study, the installation effects of a windbreak net on reducing wind speed were examined using meteorological observation data. Three automatic weather systems (AWS) were installed at the inside of the windbreak net of an apple orchard along the distance, and one AWS was located at the outside. They were set up on Oct. $25^{th}$, 2012 at the apple orchard of Geochang County, and meteorological data, which were observed at four stations for about 1 year from October 26, 2012 through October 21, 2013, were used for this study. Meteorological variables include air temperature & relative humidity at a height of 1.5 meter, and wind speed & wind direction at a height of 2 meter and 4 meter. These variables were measured and recorded every 60 seconds. The preliminary results of this study was as follows: (1) Daily mean temperature at the inside of the windbreak net was lower than that of the outside by 0.1 through $0.2^{\circ}C$. (2) Daily mean relative humidity at the inside of the windbreak net was higher than that of the outside by 0.7 through 1.7%. (3) As compared to the outside, northerly daily maximum wind speed of the inside of the windbreak net at a height of 2 and 4 meter was reduced by 0.7~1.5 $ms^{-1}$ (30.4~65.2%) and 0.3~0.7 $ms^{-1}$ (10.3~24.1%), respectively.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.264-271
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• 2015

Stink bugs do damage on various crops including upland crops and tree fruits. Especially, yellow-brown stink bug (Halyomorpha halys ($St{\aa}l$)) and brown-winged green (Plautia stali) are severely damaged on apple orchard. Using seven insecticides - dinotefuran WP, etofenprox WP, chlorpyrifos WP, cabaryl WP, chlothianidin SC, flonicamid WG, and bifenthrin WG - registered on apple, contact and residual toxicities were tested on both male and female of P. stali and H. halys that preferred apple fruit. Contact toxicity of dinotefuran WP was excellent on male P. stali 48 hours after treatment (HAT) with 96.7% and significant on male Halyomorpha halys 48 HAT with 74.5% but the others had low effect. Contact toxicity on these stink bugs were higher in male than female. All insecticides except flonicamid, residual effects were all effective on both male and female of P. stali, while chlorpyrifos and bifenthrin were showed higher residual toxicity on both male and female of H. halys in laboratory condition. Two insecticides, chlorpyrifos and bifenthrin, were selected for the field test. Bifenthrin have a high residual effect on P. stali until 5 days after treatment, but have a low residual toxicity on H. halys in the field test. Chlorpyrifos showed higher residual toxicity in the laboratory, however, showed low residual efficacy on two species stink bug onto the field.