• Research in Plant Disease
• /
• v.10 no.3
• /
• pp.203-208
• /
• 2004

The dominant isolates of Colletotrichum gloeosporioides from the red pepper anthracnose(both of the diseased plants and debris) was more pathogenic than the isolates of Colletotrichum acutatum of minorly isolated from Gyeong-buk, Korea. There were both of the G and R strains of cultural variants of Colletotrichum gloeosporioides, the G strain was more pathogenic than R strain. The cultivars of red-pepper, cv. 'Kumsegi' was the most susceptible and cv. 'papet' was the least susceptible in the pathogenicity test. The isolates of Colletotrichum gloeosporioides from other host plant such on sesame, safflower, yam, strawberry could infect to the red pepper plant also.

• Research in Plant Disease
• /
• v.19 no.2
• /
• pp.121-123
• /
• 2013

The strains of Colletotrichum gloeosporioides, C. coccodes, C. acutatum isolated from black raspberry were pathogenic to apple and strawberry after dropping inoculation, but showed weak pathogenicity in hot-pepper and tomato. The anthracnose pathogens of C. gloeosporioides, C. orbiculare, C. acutatum isolated from apple, hot-pepper and pumpkin showed pathogenicity in black raspberry. Moreover, the anthracnose pathogens isolated from apple caused disease symptoms in non-wounded inoculation.

• The Plant Pathology Journal
• /
• v.23 no.3
• /
• pp.187-192
• /
• 2007

The anthracnose disease on pepper fruits in Korea was caused by Colletotrichum acutatum as well as C. gloeosporioides. Since C. acutatum showed less sensitivity to benomyl, it was analyzed whether the less sensitivity was given by the same mechanism for the fungicide resistance of C. gloeosporioides. The isolates of C. acutatum were less sensitive to the three benzimidazole fungicides tested, benomyl, carbendazim, and thiophanate-methyl. However, the of C. acutatum isolates were different from the resistant isolates of C. gloeosporioides in their response to diethofencarb, one of N-phenyl-carbamates; the former was still less sensitive to diethofencarb than the latter. The differences in the resistance mechanisms in two species were conspicuous in sequence analysis of the tub2 genes. The genes from C. acutatum did not show any non-synonymous base substitutions at the regions known to be correlated with the benzimidazole-resistance. All of these data may indicate that the less sensitivity of C. acutatum to benomyl is based on different mechanism(s) from that of C. gloeosporioides.

• Research in Plant Disease
• /
• v.10 no.3
• /
• pp.198-202
• /
• 2004

The overwinter and survival of Colletotrichum gloeosporioides and Glomerella cingulata in strawberry tissues under field conditions was investigated in 2001 and 2002. The rates of overwinter survival in plant petiole, runner and crown were 68.7,14.3, and 26.7％, respectively. But, under field condition, viable conidia of overwinter were not detected at the surface, 3, 5, and 10 cm depths of soil. To investigate the survival ability in soil and plant debris, C. gloeosporioides and G. cingulata isolates from strawberry were examined in laboratory and field. The viability of conidia was rapidly declined in all the treatments, with a 40％ reduction in population within 10 days. In soil, the survival ability of G. cingulata conidia was similiar to that of C. gloeosporioides. The survival rate of conidia was highest under cool and dry soil conditions, and was decreased by increasing both soil temperature and moisture content. Similar results were also obtained under the condition that infected petioles were buried in soil. Results suggested that conidia as well as plant debris might be a main primary inoculum source of strawberry anthracnose.

• Research in Plant Disease
• /
• v.13 no.2
• /
• pp.119-121
• /
• 2007

Anthracnose of Salvia plebeia caused by Colletotrichum acutatum was observed in the exhibition field of Hamyang-gun, Gyeongsangnam-do Agricultural Research and Extension Services, in Korea. The disease mainly occurred on the leaves, petioles and stems of whole plant. The typical symptoms were water-soaked lesions on stems and petioles, rotted stems and withering then eventually died. The color of colonies of the pathogenic fungus grown on potato dextrose agar was pinkish gray. Conidia were fusiform in shape and was $8{\sim}17{\times}3{\sim}4\;{\mu}m$ in size. Appressoria were pale to dark brown in color, clavate in shape and the sizes were $8{\sim}11{\times}4{\sim}6\;{\mu}m$. Optimum temperature for mycelial growth was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Colletotrichum acutatum J. H. Simmonds. This is the first report on the anthracnose of S. plebeia caused by C. acutatum in Korea.

• Research in Plant Disease
• /
• v.12 no.2
• /
• pp.119-121
• /
• 2006

Anthracnose of pomegranate (Punica granatum) caused by Colletotrichum acutatum was observed in the exhibition field at Hamyang-gun, Gyeongsangnam-do Agricultural Research and Extension Services, and in farmer's orchard at Gaheo-myon, Hapcheon-gun, Gyeongnam province, Korea. The pathogen generally attacks on the fruits and induces dark lesion and rotting. The infected fruits were mostly dropped or mummified. The color of colonies of the pathogenic fungus grown on potato dextrose agar was pinkish gray. Conidia were fusiform in shape and was $8{\sim}16{\times}3{\sim}4{\mu}m$ in size. Appressoria were pale to dark brown in color, clavate in shape and was $8{\sim}12{\times}4{\sim}6{\mu}m$ in size. Optimum temperature for mycelial growth was $25^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulate. On the basis of mycological characteristics and pathogenicity test on fruit, the fungus was identified as Colletotrichum acutatum. This is the first report on the anthracnose of pomegranate caused by C. acutatum in Korea.

• The Plant Pathology Journal
• /
• v.23 no.2
• /
• pp.37-44
• /
• 2007

Colletotrichum contains many important pathogens which cause economically significant diseases of crops like pepper, strawberry, tomato and apple. Forty four isolates were collected to characterize the diversity of Colletotrichum causing apple anthracnose in various regions of Korea. They were analyzed by random amplified polymorphic DNA (RAPD), internal transcribed spacer (ITS) of rDNA and partial $\beta$-tubulin gene DNA sequence, and culture characteristics on PDA and PDA-Benomyl. From the results of molecular analyses, 31 strains belonged to Colletotrichum gloeosporioides, ribosomal DNA group (RG) 4 of Moriwaki et al. (2002), 8 strains belonged to C. acutatum, A2 group of Talhinhas et al. (2005) and 5 strains to C. acutatum, A3 group of Talhinhas et al. (2005). Most isolates of C. gloeosporioides RG4 grew faster on PDA than strains of C. acutatum, A2 and A3 groups and most RG4 strains were sensitive to Benomyl. However, a few strains of RG4 grew slower and were resistant to Benomyl. On the basis of molecular characteristics, apple isolates of C. acutatum were clearly differentiated from red pepper isolates of the species, but apple isolates of C. gloeosporioides were not.

• Horticultural Science & Technology
• /
• v.28 no.4
• /
• pp.540-544
• /
• 2010

The nursery plant quality and flower bud induction of new strawberry cultivars, 'Maehyang' and 'Seolhyang' in forcing culture were evaluated in the highland and lowland region. In order to produce daughter plants, the new cultivars were grown in the open field located at both highland (Daekwallyung, above 800 m sea level) and lowland (Gangneung, above 20 m sea level) region, respectively. The average air temperature at highland during nursery plant propagation period was $5.3^{\circ}C$ lower than those at lowland. The number of daughter plants produced at lowland was 2 times as high as those of highland, presumably due to the higher air temperature. Anthracnose incidence rates of runner plants produced at lowland were 4 to 7% as high as those in highland. Mean temperature in the highland ($23.5^{\circ}C$) during flower bud differentiation treatment was $5.1^{\circ}C$ lower than that in the lowland ($28.6^{\circ}C$). Seedlings produced in highland showed higher C/N ratio and lower T/R ratio compared to those produced in lowland. The average flower bud formation date of the daughter plants grown in highland were advanced by 30 days compared to the date in lowland. Accordingly, highland was supposed to be appropriate region for raising seedlings in forcing culture of the new strawberry cultivars of 'Maehyang' and 'Seolhyang'.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.385-391
• /
• 2012

This study was conducted to investigate the effects of the runner cutting time on the growth and yield of strawberry (Fragaria ${\times}$ ananassa cv. Maehyang and Seolhyang) during nursery period of two consecutive years (2009 and 2010). Strawberry runners which connected from mother plants to daughter plants were cut 30, 20, 10 and 5 days before transplanting day (11 Sep. 2009 and 10 Sep. 2010). When runner cutting time delayed, more nutrition was supplied to the daughter plant until late nursery period. It showed that there was a tendency to increase the fresh weight, crown diameter and leaf chlorophyll content. On the other hand, when the runner was cut earlier, the growth of underground part such as root weight was improved. Irrigation demand increased to 29.7% in case of runner cutting from mother plant compared with runner non-cutting treatment. In addition, infection ratio of anthracnose through runner part was 37.6% higher in case of runner cutting than that of runner non-cutting treatment. After transplanting, budding and flowering period were delayed up to 2 or 3 days because of late runner cutting. But there was no significant difference in marketable fruit yield among runner cutting times. It is recommended to conduct runner cutting 5 or 10 days before transplanting for reducing the occurrence of anthracnose.

• The Korean Journal of Pesticide Science
• /
• v.19 no.1
• /
• pp.47-53
• /
• 2015

Various diseases occur in fruits, leave and roots during strawberry cultivation and cause severe economical damage and huge amount of chemical fungicide use. Recently, as consumers' interest in safety of foods and organic agriculture produces have increased, control measures using alternatives for chemical fungicides have been newly developed in various ways. This study was conducted to test antifungal activity and control effect of sodium dichloroisocyanurate (NaDCC), using as disinfectants, against major disease pathogens of strawberry, Fusarium oxysporum (Fusarium wilt), Colletotrichum gloeosporioides (Anthracnose) and Phytophthora sp. (Phytophthora blight), and Xanthomonas fragariae (bacterial angular leaf spot) and evaluate availability as environment-friendly materials. When NaDCC was treated at the concentration range of 150 to 300 ppm, it suppressed significantly hyphal growth and reduced spore germination by more than 28%. In field condition, NaDCC showed excellent control effect (control value: 50%) against the bacterial angular leaf spot disease. Based on above-described results, we suggested that NaDCC can be used as alternative candidates to chemical pesticide alternatives of for controlling strawberry diseases.