• Research in Plant Disease
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• v.24 no.1
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• pp.52-58
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• 2018

Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.290-290
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• 2009

유기 배 과수원의 생물종 다양성을 조사한 결과, 월동 직후 유기배 과수원에서는 13종 503마리, 관행 과수원에서 11종 145마리의 토양 미소동물이 채집되었다. 채집된 종류는 거미, 지네, 노래기와 곤충들이다. 유기과수원에는 특히 응애와 거미가 많이 채집되었으며 특히 곤충 중에서 톡토기는 247마리로 관행에 비해 7배가 많이 채집되었다. 또한 생태지수인 종다양도가 관행 1.383에 비해 1.589로 더 높았다. 서식지별 분포를 보면 나무 바로 밑의 개체수와 종수가 더 많아 배나무 뿌리를 중심으로 생활하고 있음을 확인하였다. 여름철 토양동물의 분포는 달팽이, 지렁이를 비롯한 미소 동물들이 유기인증 과수원에는 24종 632마리, 관행에서는 15종 340마리가 채집되어 유기인증 농가에서 월등히 많은 토양동물이 살고 있었으며 종다양도역시 유기농가 2.021로 관행인 1.652보다 높았다. 청목(1985)의 자연도 평가 A그룹종은 환경저항성이 낮아 쉽게 소멸되는 그룹으로 애지네, 노래기 땅지네 등이 여기에 속하는데 유기농가에서 개체수들이 더 많이 채집되었다. 추락트랩을 이용한 조사에서 딱정벌레 중 점박이먼지벌레가 관행 과수원에서 월등히 높았으며 유기농가에서는 큰넓적송장벌레가 채집되어 이들 종이 지표종으로 선발될 수 있을 것으로 보인다. 또한 거미류 중에 수풀오소리거미가 많이 채집되었으며 채찍늑대거미, 꼬마게거미, 점게거미등은 유기농가에서만 채집되어 추후 이들 종이 지표종으로 선발될 가능성이 있었다. 말레이트랩에서는 고치벌과 맵시벌 종류가 많이 채집되었고 파리류에서는 초파리가 많았으며 털검정파리는 유기인증 농가에서 만이 채집되었다. 유아등을 이용한 야간 곤충류를 채집한 결과 유기농가에서 16종 201마리, 관행 9종 42마리가 채집되어 야간에 활동하는 곤충류 역시 유기농가가 많았다. 추락트랩과 말레이트랩모두 유기인증 농가에서 종다양도가 관행보다 높았으며 유아등 채집에서도 마찬가지 결과를 보여 유기배 과수원이 토양 뿐 아니라 배를 중심으로 생활하는 모든 동물들의 종 다양성이 우수함을 알 수 있었다.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.347-357
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• 2014

This study was conducted to evaluate the control effect of sodium dichloroisocyanurate (NaDCC) for Venturia nashicola on Niitaka pear during flowering period. As a nontoxic disinfectant, sodium dichloroisocyanurate is widely used in the field of hygiene and disease prevention, medical treatment, aquiculture as well as plant protection. NaDCC was sprayed on the pear tree inoculated with conidia ($4.5{\times}10^5spores/mL$) of Venturia nashicola and as a result the incidence of pear scab was 23.8% in 750mg/L and 26.2% in 1,000mg/L compare to the 51.6% incidence in untreated tree. No damage in the pollen of pear flower was detected with NaDCC treatments in the full bloom period for six pear cultivar including Wonwhang. A NaDCC single treatment in the early bloom of Niitaka pear showed more than 98% of fertilization rate. Furthermore, there was no incidence of Venturia nashicola on Nitaka pear trees treated with NaDCC 4 times during their growth period.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.549-557
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• 2010

This study was established on which germanium (Ge), known as one of the functional nutrients, treatment is the most effective method for increasing Ge uptake and contributing flowering development in the pruned branches in the winter. Ge treatment included foliar application, soil fertigation, trunk injection, and the three-combined application. Ge concentration in the pruned branches was greater on the three-combined treated trees, and Ge treated branches had greater Ge concentrations than the control. Pruned branches grown in the solution culture had greater bud weight and bud scale number on the Ge treated trees than the control. Ge treatments increased flowering per branch and flower number per bud as well as improved resistance of the freezing temperature damage. Overall, there were no consistent results of all the variables by the Ge application methods.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.541-548
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• 2010

This study was established on which the selenium (Se), known as one of the functional elements in the human body, treatment was the most effective for the Se uptake in the soil and tree. Se treatments included foliar application, soil fertigation, and trunk injection. Se fertigation and control had similar soil $P_2O_5$, K, and Mg concentrations, and calcium and Se concentrations in the soil were greater on the control and Se fertigation, respectively. Leaf characteristics were not different among the treated trees. No differences were observed for the leaf K and Ca concentrations among the treated trees, and foliar Mg was greater on the Se treated trees than the control. Se foliar application and trunk injection had greater Se concentrations in the leaves and fruits than the Se fertigation and control.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.83-92
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• 2011

This study was established to investigate the effects of Ca application on fruit mineral nutrients, quality, and browning of 'Fuyu' sweet persimmon (Diospyros kaki). Ca foliar application at 40ml/20L/tree had a greater fruit Ca concentration than did control, Ca fertigation (40ml/20L/tree), and Ca foliar application (40ml/20L/tree) coupled with IBA fertigation (40ml/20L/tree). Fruit mineral nutrient concentrations for Mg, B, and Mn were similar or lower in the foliar treatment compared to other treatments. Fruit color was not affected. Ca treatment, whether foliar applied or fertigated, was effective in maintaining fruit firmness and in decreasing the browning symptom in fruit after MA storage at $0^{\circ}C$ for 60 and 100 days. Although Ca foliar application + IBA fertigation treatment improved fruit firmness, the positive effect on the browning and decay occurrences in fruit was not shown.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.7-14
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• 1984

Recently, a symptom similiar to black spot caused by Alternaria kikuchiana on the pear leaves is prevailing in Naju, Chonnam Province. This experiment was conducted in order to clarify causal agent and to survey present status on it. Disease lesions on the leaves were brown or black brown in color, circle or irregular circle in shape, $2\~6mm$ in diameter, and faintly zonal. Central part of lesions was gradually changed to greyish-white. The causal fungus was identified as Alternaria kikuchiana Tanaka causing black spot of pear reported previously on variety I-sib-se-gi (Nijisseki) of pear. However, this disease differed from that of typical black spot reported already in some aspects; It occurred more highly on matured leaves than on young ones. And it occurred severely in varieties Shin-heung, Shin-ko, Man-sam-gil(Okusankichi) etc. which have been reported as resistant varieties, while slightly in varieties Cho-ok(Hayadama), Park-da-cheung (Hakadahare) etc. which have been known as susceptible ones. From the results described above, it is considered that this disease is due to the differentiation in pathogenicity of Alternaria kikuchiana Tanaka in that area.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.251-255
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• 2020

In 2019, the ash whitefly, Siphoninus phillyreae (Haliday, 1835), was firstly found on a pear tree in Jinju-si, Gyeongsangnam-do. From occurrence survey, we confirmed that S. phillyreae was occurred in seven cities, Busan, Changwon, Jinju, Gwangyang, Suncheon, Goheung, and Goseong. In addition, seven plants, such as Punica granatum, Pyrus pyrifolia, Cydonia oblonga, Prunus mume, Crataegus pinnatifida, Eriobotrya japonica, Photinia glabra, Pyracantha angustifolia, Lagerstroemia indica, and Malus prunifolia, were detected as hostplants. In this study, we present the first report of this species in Korea and describe the damage caused by S. phillyrease and its taxonomic information.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.96-106
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• 2002

Five major naturally populated habitats around the Mt. Daeduk, Gangwon province for wild Chuiangne (Pyrus ussuriensis var. acidula) are mostly located on the southeast side of the mountains at 1,216-1,306ｍ in altitude at sea level and are in very good sunney areas. The total of 96 taxa dividing into 40 families, 79 genera 84 species and 12 varieties have in these areas. Most of these plants are heliophytes, which love sunshine, Compositaes such as Artemisia stolonifera, Synurus deltoides, or Rosaceaes like Potentilla fragarioides var. major are also shown. These areas have been unknown destroyed, so it is possibly thought the second transition has been progressed. The index of species diversity of plant groups in these areas is 4.715-5.270 based on the Shannon-Wiener's method. The wild Chuiangne with 34.15％, which are 5-10㎝ DBH, have been found in habitats. The vegetation around the habitats must be managed by the man in order to keep sound growth of the wild Chuiangne.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.175-183
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• 2016

BACKGROUND: There's a long rainy season during the Summer in Northeast Asia, including Korea. Heavy rainfall during this season causes harm to tree's root, and damped injury in the pear has been continuously reported. Pear Research Institute is breeding damp resistant rootstocks and investigating their mechanisms to relieve damped damages in the pear.METHODS AND RESULTS: Seedlings of Pyrus betulaefolia and P. calleryana were divided into two groups: control and damped, respectively. Damped group was treated by constant irrigation for 77 days and control group was maintained to keep the soil moisture pressure between 0 and -10 kPa. After the treatment, we analysed trees' growth rate, chlorophyll content, amino acids and total phenolic compounds. As a result, P. betulaefolia was sensitive to damped treatment while P. calleryana did not have significant differences between the control and damped treatment. It was observed that total contents for phenolic compounds were dramatically increased in P. betulaefolia while trees' growth rate, chlorophyll b and general amino acid contents were lowered by damping treatment.CONCLUSION: In some pear cultivars, growth habit is suppressed by damped damage. Pyrus calleryana displayed tolerances to damped damage in growth rate and some organic compound contents compared to P. betulaefolia. So we recommend to exploit P. calleryana as a pear rootstock rather than using P. betulaefolia.