• Research in Plant Disease
• /
• v.30 no.1
• /
• pp.34-49
• /
• 2024

The development of sustainable smut management techniques requires an understanding of the impacts of smut on sugarcane growth and the relationships between smut intensity and meteorological variables, varieties, and crop types. Thus, assessments were made with the objectives to 1) determine the effect of smut on the above-ground growth of sugarcane, and 2) quantify the association of smut with weather variables, varieties and crop types. The effect of smut on above-ground growth was assessed in six fields planted with NCo 334 (wider coverage) having 6 months of age in Fincha and Metehara fields in 2021. Data on above-ground growth were taken from 20 randomly selected smut-affected and healthy stools from each field. Besides, 6 years' data (2015 to 2021) on the numbers of smut-affected stools and smut whips of 79 fields were collected. Furthermore, 10 years' (2011 to 2021) weather data were acquired from the sugar plantations. The results demonstrated reduction in the above-ground growth of sugarcane in the range of 18.39% and 73.42% due to smut. In addition, weather variables explained about 68.48% and 66.58% of the variability in the number of smut-affected stools and whips respectively. Smut intensity increased with crop types for susceptible varieties. The tight association between the smut epidemic and crop types, varieties, and weather, implied that these parameters must be carefully considered in management decisions. Continuous monitoring of smut disease, meteorological variables, varieties, and crop types in all the sugarcane plantations could be done as a part of integrated smut management in the future.

• Research in Plant Disease
• /
• v.8 no.1
• /
• pp.34-40
• /
• 2002

Different types of smut fungi have been reported from different geographical places, depending on the distribution of host plant. Therefore, a survey was conducted to investigate the host plant of smut fungi and occurrence situations in three Asian countries. As a result 12 genera of 4 families and 19 species,24 families 87 genus and 191 species, and 12 families 140 species were occurred in Korea, Japan and China, respectively. Six genera(Enty-loma, Yilletia, Sorosporium, Sphacelotheca, Urocysitis, Ustilago) of korean smut fungi species were reported until 1998. In Japan, Ito reported for first time 14 genera and 140 species of smut fungi in 19361 and then were more described into 17 genera 114 species by Kaki hits a in 1984. Two genera (Schizonella and Namnfldtiomyces) and 8 species were newly listed, later by other researchers. In China, Ling reported that smut fungi classified into 14 genera, 109 species in 1953. In addition, Liroa, Glomosporium, Gahmphopora and Microbotryum genus including 49 species were recently reported, thus 18 genera and 158 families of smut fungi in China. These results suggest that the number of plant related with smut fungi is seemed to be more increase in future. Smut disease, occurred on the whole or part of plant and flower.

• Research in Plant Disease
• /
• v.7 no.2
• /
• pp.102-106
• /
• 2001

Currently the rice false smut caused by Ustilaginoidea virens (Cooke) Takah. has occurred widely in Korea. A survey on the disease incidence at rice fields in 8 inland provinces was carried out in 2000, showing that the disease occurred at 104 (7.5%) out of 1,152 rice fields examined, ranging from 1.5% to 13.7% in provincial average. It was found that the disease incidence was greatly affected by local weather conditions and rice cultivars. In case of the most susceptible cultivar Namchunbyeo, the disease incidence was only about 1.3% in Icheon, while it was over 20% in Namwon which had weather conditions of the shorter sunshine period (about 64%) and the higher amount of precipitation (about 130%) during the rice cultivation than Icheon. In Icheon, artificial inoculation of the pathogen failed to induce the disease, probably because of the weather conditions unfavorable to the disease development, which also suggests that its incidence may be dependent on the weather conditions. Susceptibility of rice cultivars to the disease varied greatly; eight resistant cultivars including Heukjinjubyeo were not damaged by the disease, but 2 cultivars including Geumnambyeo and Namchunbyeo were severely damaged, having more than 20% of the disease incidence. Among chemicals tested fur the control of the rice false smut tebuconazole WP showed the highest control efficacy of 83∼88% on cvs. Geumnambyeo and Namchunbyeo. Other chemicals such as azoxystrobin WP and ferimzone WP also effectively suppressed the disease development in the field trials.

• Korean Journal of Medicinal Crop Science
• /
• v.8 no.1
• /
• pp.79-82
• /
• 2000

This study was carried out to investigate the effect of seed disinfectant on leaf blight and smut in adlay. Leaf blight and smut disease in adlay are known to be seed borne. Bjpolan's cojds, pathogen causing leaf blight in adlay, was detected from 32. 7 to 45. 7 % on seeds collected from adlay cultivated farms in Yonchon province. Periods of seed infestation are $0{\sim}7$ days on the variety 'yulmu 1' and $0{\sim}20$ days on 'Yonchon jaerae'. Distribution ratio of seed disinfestation periods was that no disinfestation, $1{\sim}5$days, $6{\sim}10$days and more 11days were 20%, 20%, 45% and 15%, respectively. Frudioxonil W. S. treatment was effective on inhibition of leaf blight and smut disease when treated with infested seeds ; that is, disease control values of the fungicide are 97 and 93.4 percentage, repectively.

• The Plant Pathology Journal
• /
• v.37 no.3
• /
• pp.291-298
• /
• 2021

False smut caused by Ustilaginoidea virens is an important rice fungal disease that significantly decreases its production. In the recent past, conventional methods have been developed for its detection that is time-consuming and need high-cost equipments. The research and development in nanotechnology have made it possible to assemble efficient recognition interfaces in biosensors. In this study, we present a simple, sensitive, and selective oxidized graphene-based geno-biosensor for the detection of rice false smut. The biosensor has been developed using a probe DNA as a biological recognition element on paper electrodes, and oxidized graphene to enhance the limit of detection and sensitivity of the sensor. Probe single-stranded DNA (ssDNA) and target ssDNA hybridization on the interface surface has been quantitatively measured with the electrochemical analysis tools namely, cyclic voltammetry, and linear sweep voltammetry. To confirm the selectivity of the device, probe hybridization with non-complementary ssDNA target has been studied. In our study, the developed sensor was able to detect up to 10 fM of target ssDNA. The paper electrodes were employed to produce an effective and cost-effective platform for the immobilization of the DNA and can be extended to design low-cost biosensors for the detection of the other plant pathogens.

• Korean Journal of Agricultural Science
• /
• v.12 no.2
• /
• pp.242-252
• /
• 1985

In order to get information on the ecology of rice false smut, germination ability and pathogenicity of sclerotia and chlamydospores of the pathogen, environmental conditions affecting the disease outbreak and varietal resistance have been investigated. 1. The degree of outbreak of rice false smut was higher in the upland rice in comparison with the paddy field rice in respect to the number of affected grains per ear, the size and weight of smut balls formed on affected grains as well as the ratio of sclerotial formation produced on smut balls. 2. Germination percentage and days required for germination of overwintered sclerotia placed on the soil surface in July were 81% and 19 days, respectively, while those of overwintered sclerotia treated in May were 60-70% and 41 days. Sclerotia placed on the soil surface or under 1 cm depth of the soil surface and incubated at $25-30^{\circ}C$ were germinated well, whereas those placed under 3 cm or 5 cm depth of the soil surface were not germinated at all. Germinability and stroma productivity of sclerotia were reduced when the sclerotia were cutted into small pieces. 3. The average number of stroma formed on a sclerotium was six and that of perithecia formed in a stroma was about 50 to 140. 4. Percentage of germination of chlamydospores on the yellow balls was very high and was decreased as the color of the balls being darken with maturation. 5. Panicle of rice plants were successfully infected by injection inoculation with suspention of ascospores and chlamydospores of the pathogen to the sheaths at the booting stages, while seeding infection by spraying with suspensions of chlamydospores was unsuccessful. 6. More number of infected grains was distributed on basal parts of an affected ear than that of infected ones distributed upper parts of the ear, when the affected ear was divided into five parts from its basal portion to the apical of the ear. 7. The occurrence of the disease was more severe in the late maturing varieties of rice in comparison with the early maturing varieties. 8. When the level of nitrogen applied was increased, the incidence of disease increased, and the infection percentage of the disease was increased as the transplanting date was delayed. 9. The weight of panicles and 1000 kernels and the ratio of ripenness were reduced, and the contamination degree of grains with chlamydospores were increased as the number of smut balls per panicle were increased.

• Mycobiology
• /
• v.49 no.3
• /
• pp.275-279
• /
• 2021

A fungus of the genus Kordyana, found on leaves of Commelina communis and C. minor exhibiting white smut-like symptoms, was identified as Kordyana commelinae based on morphological characteristics and two rDNA sequence analyses. We report the novel occurrence of the genus Kordyana in Korea and the association of K. commelinae with the host plant species. As well, we provide the necessary mycological information to resolve species delimitation and taxonomic problems of Kordyana.

• Research in Plant Disease
• /
• v.18 no.3
• /
• pp.250-254
• /
• 2012

In July 2011, hundreds of garden cosmos (Cosmos bipinnatus) were found to be infected with a white smut in Namyangju. Further surveys in central Korea showed that the disease occurred in all the nine localities visited, with disease incidence rate of >50%. Symptoms manifested as pale-green to chlorotic areas on the leaves, followed by white mildew development on lesions. The lesions usually coalesced and became necrotic, considerably reducing the aesthetic value. Caespituli were initially hypophyllous but later epiphyllous as well. Conidiophores were 10-40 in moderately dense fascicles, hyaline throughout, mostly guttulate, $20-45{\times}2-4{\mu}m$, obtuse at the apex, and had inconspicuous conidial scars. Conidia were solitary, botuliform, hyaline, aseptate, mostly guttulate, apex rounded, base rounded to truncate, $17-24{\times}3.5-5{\mu}m$, hilum inconspicuous, unthickened, and not darkened. Sori were rounded to elongated, resulting in first white and later brown leaf spots. Teliospores embedded in the leaf tissue were subglobose to ellipsoidal, subhyaline to pale yellowish-brown, $12.5-20{\times}10-15{\mu}m$. These morphological characteristics corresponded with those of Entyloma cosmi V$\acute{a}$nky, Horita & Jage. This is the first report of white smut disease of garden cosmos due to infection of E. cosmi in Korea.

• Korean Journal Plant Pathology
• /
• v.12 no.3
• /
• pp.297-301
• /
• 1996

옥수수 깜부기병균에 대한 살균제 활성검정시 실내 검정과 온실 유묘검정과의 상관정도를 조사하기 위하여 5가지 살균제를 공시하여 실내와 온실에서 깜부기병균에 대한 억제효과를 비교하였다. 실내검정방법으로 사용한 최소생육억제농도법, 저지원법, 소생자발아검정법의 결과는 모두 온실유묘검정에서 얻어진 결과와 상관이 높았으며 특히 저지원법은 유묘검정결과와 매우 높은 상관관계를 보였다. 따라서 저지원법과 같은 실내검정방법은 대량의 활성검정시 간이검정방법으로 유용하게 이용될 수 있으리라 생각된다.

• Research in Plant Disease
• /
• v.16 no.2
• /
• pp.183-190
• /
• 2010

During the period from 1999 to 2008, we surveyed the major diseases incidence of rice in Korea. Leaf blast showed 0.85% of the diseased leaf area in 2000 and then consistently decreased to 0.02% by 2008. However, panicle blast irregularly appeared by the years depending on weather conditions for disease development from heading to milk stage of rice. Diseased lesion height of sheath blight had the lowest (10.1%) incidence in 2001 and the highest (21.4%) incidence in 2007. A negative corelation ($r=-0.88^*$) was measured between diseased lesion height of sheat blight and sunshine hours from mid- to late August. In Chunbuk, Gyeongbuk, and Gyeongnam provinces, brown spot occurrence declined since 2001, however, in Chungnam, Jeonbuk, and Jeonnam provinces, it increased since 2005. False smut drastically decreased after showing the highest incidence of 7.59% in panicles in 2000. The correlation coefficient between diseased panicles of false smut and rainfall during the late August was calculated as $0.94^{**}$. Bacterial leaf blight severely increased in the chronically infested fields in Jeonnam, Jeonbuk, Gyeongnam, and Chungnam province since 2003.