• The Korean Journal of Pesticide Science
• /
• v.17 no.4
• /
• pp.460-467
• /
• 2013

This study was conducted to reduce the using amount of chemical fungicides for the control of red-pepper Phytophthora blight. Effect of combination application of two microbial fungicides and two chemical fungicides for the control of red-pepper Phytophthora blight was examined in vitro, in greenhouse and under field conditions. Each microbial fungicides and chemical fungicides was two-fold diluted and mixed-soil drenched. In the greenhouse pot assay, the mixed application of B. pumilus QST2808 and a mixture of dimethomorph + ethaboxam (De) among four mixed applications of two microbial fungicides (B. pumilus QST2808, P. polymyxa AC-1) and two chemical fungicides showed the highest control effect against Phytophthora blight. Also, control effect of mixed application of B. pumilus QST2808 and De was similar to that of single application of De (dimethomorph + ethaboxam) or Mo (mancozeb + oxadixyl). In the field test, when the microbial fungicides (B. pumilus QST2808, P. polymyxa AC-1) and the chemical fungicide(De) for the control of Phytophthora blight of red pepper were mixed-soil drenched four times at 7~10 day-intervals, the control values were in the range of 78.8% to 82.0%. On the other hand when each of the two chemical fungicides (De, Mo) were soil drenched four times at 7~10 day-intervals, the control value were 65.7% to 85.8%. Consequently, the mixed application of the microbial fungicides and chemical fungicides could be recommended as a control method for reducing the using amount of chemical fungicides.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 1999.10a
• /
• pp.41.1-41
• /
• 1999

• Korean Journal of Environmental Agriculture
• /
• v.15 no.3
• /
• pp.289-295
• /
• 1996

This study was attempted to select an antagonist against Phytophthora blight of red-pepper caused by Phytophthora capsici. The three strains, A-35, A-67 and A-183 were isolated from the rhizosphere in soil where red-pepper had been cultivated continuously for a long time, and the strain A-83 was estimated to be the strongest antagonist against P. capsici. The A-183 strain was identified as a strain of Pseudomonas sp., showing the maximum antifungal activity, when cultured at $30^{\circ}C$ for 5 days in the potato extract medium(pH 6.5) containing 2.0% mannitol and 0.3% peptone.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.3
• /
• pp.180-185
• /
• 2001

Control effects of phosphorous acid were investigated on Phytophthora blight of red pepper plants in greenhouse and field. In vitro test, the mycelial growth of Phytophthora capsici was inhibited by the phosphorous acid more than 97% at 1,000 ${\mu}g$ and 10,000 ${\mu}g$ a.i./mL in the liquid and solid culture, respectively. At concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid, in the liquid culture the mycelial growth of P. capsici was inhibited 46.2%, however inhibited only 4.9% on the soild culture. Zoosporangial formation was also inhibited 89.1% by phosphorous acid at 100 ${\mu}g$ a.i./mL. Phosphorous acid affected more zoosporangial formation of P. capsici than its mycelial growth. At the concentrations of 10,000, 1,000 and 100 ${\mu}g$ a.i./mL of phosphorous acid, germination of zoosporangia was inhibited 100, 84.3 and 44.2%, respectively. Mycelial growth and zoosporangial formation of P. capsici were little affected at the concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid. Cermination of zoosporangia was also little affected at this concentration, however growth of the germ tubes was inhibited and the abnormal mycelial growth was observed. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to $77.0{\sim}62.0%$, in greenhouse. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to 54.0% at the conventional culture in field. Treatments of phosphorous acid increased up to 113% in height, 135% in number of fruit, and 129% in weight of fruit.

• The Korean Journal of Mycology
• /
• v.23 no.2 s.73
• /
• pp.114-120
• /
• 1995

Colletotrichum dematium, C. gloeosporioides and Glomerella cingulata were detected in seed samples collected from diseased red pepper (Capsicum annuum) using blotter method. C. gloeosporioides was the predominant species in seed samples tested and followed by C. dematium and G. cingulata. When the seed components were plated C. dematium, C. gloeosporioides and G. cingulata were detected from seed coat, endosperm and cotyledon. The three anthracnose fungi were recorded more frequently from seed coat than that of observed in the endosperm and cotyledon. Seed infection with C. dematium, C. gloeosporioides and G. cingulata caused seed rotting, damping off and seedling blight of red pepper plants. According to the inoculation experiments, it was shown that C. gloeosporioides was the most virulent among three species. C. dematium showed weak virulence when the plants were wounded, and G. cingulata was wound parasite or weakly virulent on red fruits. Benlate T (benomyl+thiram) and Homai (thiophnate-methyl+thiram) were effective to anthracnose fungi when treated to infected seeds.

• Korean Journal of Organic Agriculture
• /
• v.6 no.2
• /
• pp.117-125
• /
• 1998

For isolation of antagonistic fungi antagonistic to Phytophthora capsici, a total of 157 isolates of fungi were screened from soil. Among the 157 isolates further screened by the dual culture test on potato dextrose agar and V-8 juice agar, 16 isolates were tested to show their antagonistic activity against P. capsici and Fusarium oxysporum. Fungal cul-ture filtrates of screened 16 isolates were shown to inhibit germination of zoospoorangia of P. capsici entirely and conidia of F. oxysporum considerably. Antagonistic fungi were shown to suppress of P. capsici infection of red-pepper plants maintained in the green house. Four isolates. 27 J5, 37 J10, 36 J13 and 31 K10, with the reduced disease incidence 53.3∼60.0% were identified as Fusarium sp. (27 J5). Trichoderma sp. (37 J10, 36 J13) and Penicillium sp. (31 K10).

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.89-92
• /
• 2005

In 2004, average temperature was higher, and rainfall was less than those of previous year, The diseases of rice, barley, pepper, chinese melon, apple and oriental pear were surveyed. Seedling diseases, leaf blast, sheath blight and bacterial blight of rice, phytophthova blight, virus diseases and anthracnose of pepper, and sudden wilt syndrome and powdery mildew of chinese melon grown in plastic greenhouse were severe. Especially, sheath blight and bacterial blight of rice occurred two times higher than those of previous year, Panicle blight of rice decreased about 4 times, compared with the previous year, presumed that the lower rainy days, rainfall and RH suppressed spread of the fungal pathogens to panicles of rice. Lower rainfall during mid- and late Aug caused three-times less occurrence of phytophtora blight of red-pepper than that of the previous year, Another diseases surveyed occurred similar or less than those of the previous year.

• Research in Plant Disease
• /
• v.17 no.2
• /
• pp.129-135
• /
• 2011

Chitosan is a linear polysaccharide composed of randomly distributed ${\ss}$-(1-4)-linked D-glucosamine and Nacetyl-D-glucosamine. There have been many reports on the induced systemic resistance and in vivo antifungal activities of higher molecular weight chitosans with molecular weights over 3,000 amu (atomatic mass unit), but there are few papers on in vivo antifungal activities of low molecular weight chitosans (oligochitosans) with molecular weights less than 3,000 amu. In our study, an oligochitosan sample (320.3,000 amu) showed a potent 1-day protective activity with control values more than 94% at concentrations of 500 and 1,000 ${\mu}g$/ml especially against tomato late blight caused by Phytophthora infestans under growth chamber conditions. It also displayed a moderate 1-day protective activity with control values of 67.89% at concentrations of 500 and 1,000 ${\mu}g$/ml against wheat leaf rust and red pepper anthracnose. On the other hand, it showed a 16-hr curative activity against red pepper anthracnose, but not against tomato late blight and wheat leaf rust. In field experiments, oligochitosan effectively suppressed the development of late blight on potato and tomato plants with control values of 72% and 48%, respectively. The results strongly indicate that oligochitosan can be used as an eco-friendly organic material for the control of late blight on tomato and potato plants.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.185-191
• /
• 2012

For initiation of resistance breeding program of the red pepper, 21 PR ($Phytophthora$ resistance) cultivars, 36 cultivars collected from USA and 'Supermanitta' which is a susceptible cultivar against phytophthora blight were assayed against phytophthora blight, powdery mildew, and anthracnose. For seedling assay of phytophthora blight, three different mating type strains of $Phytophthora$ $capsici$ were used (A1, A2, Sterile). The result showed that most of the pepper of PR cultivars were resistance or moderately resistance at each mating type. 'Yeokganghongjanggun' was resistant to all three $P.$ $capsici$ strains and 'PR-Datta' and 'PR-Manitta' were resistant or moderately resistant at each type. In case of the collected cultivars, 'NuMex J.E.Parker', 'Omni Color', and 'SCM334' were resistant to all the three types and some cultivars including 'Sweet Banana' and 'Tabasco' were moderately resistant to each type fungi. 'Orange Habanero' and 'Black Cuban' were resistant to powdery mildew and 'Supermanitta' and 'PR Keumdong' were moderately resistant, while 'Santa Fe Grande', 'NuMex Pinata' and 'Puya' were very susceptible. In the case of anthracnose, 'Aji Limon' and 'Capsicum baccatum var. pendulum 3-4' were resistant and 'Pobalno', 'Omni Color', 'Negro', 'Mesilla', 'Mulato', 'Bhut Jolokia', 'Big Dipper', 'Black Cuban', 'NuMex Pinata', and 'NuMex Big Jim' were moderately resistant. The most PR cultivars except 'Taesan' were susceptible or very susceptible. These resistant individuals identified through this experiment can be used as sources of resistance to pepper pathogens in the future breeding programs.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2005.09a
• /
• pp.74-77
• /
• 2005