• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.149-154
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• 2003

Potato blackleg disease caused by Erwinia carotovora subsp. atroseptica has been a serious problem in Korea. It was previously reported that four mixtures [streptomycin (9.3 ppm) + copper oxide (171.6 ppm)/copper hydroxide (146.3 ppm), streptomycin sulfate (7.0 ppm)+copper oxide (171.6ppm)/copper hydroxide (146.3 ppm)] were effective for the control of E. carotovora subsp. atroseptica. in in vitro test. Using those four mixtures and two antibiotics [streptomycin (81.4 ppm) and streptomycin sulfate (61.3 ppm)], the effectiveness of control for E. carotovora subsp. atroseptica. was conducted in the field. Two antibiotics showed over 60% of control efficacy under different soil conditions, while mixtures of two antibiotics with copper compounds did not show any control effects on the infected seed potato. Two mixtures [streptomycin (27.9 ppm)+copper hydroxide (438.9 ppm), streptomycin sulfate (21.0 ppm) + copper oxide (514.8 ppm)] were effective in the control of potato blackleg disease on the infected potato plants under different climate conditions.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.45-50
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• 2001

In recent, non virus-induced mosaic symptoms(NVMS) on potato leaves were observed in the seed potato fields, and its incidence rate was $5{\sim}20%$ nationwide. It made difficult to rogue out virus-infected plants, and caused much arguments between seed potato production farmers and seed potato inspectors. The objectives of these experiments were to find out the causes of NVMS, and also to induce mosaic symptom(phytotoxicity) on potato plants by treatment of several herbicides. No significant correlations were found between incidence rates of NVMS and values from soil analyses; soil pH, soil EC, organic matter content, and contents of inorganic constituents($P_2O_5,\;NO_3$, Ca, Mg, K) in the soil around the potato planted. The examinations by ELISA, virus indicator plants, and TEM showed that NVMS on potato leaves was not caused by the viruses infection. But, the use of herbicides could induced the NVMS on potato leaves. The incidence rates of potato treated with pendimethalin linuron of 400 mL/10 a, pendimethalin of 200 mL/10 a, pendimethalin.oxadiazon of 300 mL/10 a, and control were 61.1%, 47.2%, 19.4%, and 1.4%, respectively. Based on these results, we confirmed that the treatment of pendimethalin alone and in mixture with other herbicides were the reason of NVMS on potato leaves. The yields among test plots were similar except dicamba treated plot, which decreased by about 23% compared to control plot. When their progenies harvested in 1999 were planted in the following season, no symptoms of mosaic were observed.

• Research in Plant Disease
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• v.19 no.2
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• pp.90-94
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• 2013

Potato cv. 'Haryeong' was bred with high solids, resistance to late blight and good culinary quality. It has been registered as new potato variety in 2005. Tuber necrosis symptoms such as severe superficial necrosis, raised surface lesions and ringed necrotic areas were found in tubers of 'Haryeong' during storage of seed potatoes in 2010. Potato virus Y (PVY) was detected from these symptomatic tubers by the analysis of RT-PCR using a primer set specific to coat protein gene of PVY. The nucleotide sequence of RT-PCR product ($PVY^{Hkr}$) was determined and compared to those of other strains, such as $PVY^{Kor}$, $PVY^N$, $PVY^{NTN}$, $PVY^O$, and $PVY^C$ registered in GeneBank. The result showed that $PVY^{Hkr}$ was exactly the same as $PVY^{Kor}$, Korean isolate reported in 2005, except two nucleotides. To verify the PVY was responsible for the tuber necrosis symptoms shown in the tubers of 'Haryeong', a bioassay was done using two viruses (PVY and Potato leafroll virus) and five potato cultivars ('Haryeong', 'Superior', 'Atlantic', 'Dejima', and 'Chubaek'). As expected, the same necrosis symptom appeared in tubers of 'Haryeong' infected with PVY only during the storage period.

• The Korean Journal of Mycology
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• v.10 no.1
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• pp.7-13
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• 1982

Habit characteristics of imperfect and perfect stage of D. bryoniae encountered on naturally infected seeds of cucumber and pumpkin were studied by the blotter method and compared with those grown on Difco potato dextrose agar (PDA), V-8 juice agar and water agar leaf medium (WALM). Most of the pycnidiospores obtained from each isolate of this fungus grown on PDA were non-septate and microtype. Non-septate pycnidiospores were predominanted in all isolates, but a macrotype of the non-septate and a number of uniseptate pycnidiospores were produced on V-8 juice agar and water agar leaf medium. On seed the pycnidiospores were mostly non -septate, but rarely uniseptate ones were also found. On radicle of cucumber seed, the pycnidiospores were non-septate and uniseptate but small percentage biseptate with somewhat constricted at septa. Pycnidiospores produced on V-8 juice agar and water agar leaf medium were similar to those produced on seeds. In the present investigation the perithecia were mostly globose to subglobose with apical papillate ostiole and whitish spore masses formed on the ostiole of perithecia, either on naturally infected seed or on culture media. The mature perithecia were dark brown to black. They were partially embedded or erumpent on seed coat and culture media. The perithecia varied in size within a much narrower range than the pycnidia. But perithecial formation of this fungus on PDA, V-8 juice agar, WALM and seed varied considerably depending upon isolate and culture media.