scholarly journals Pythium spp. Associated with Bell Pepper Production in Florida

Plant Disease ◽  
2000 ◽  
Vol 84 (12) ◽  
pp. 1271-1274 ◽  
Author(s):  
D. O. Chellemi ◽  
D. J. Mitchell ◽  
M. E. Kannwischer-Mitchell ◽  
P. A. Rayside ◽  
E. N. Rosskopf
Keyword(s):  
Root Rot ◽  
Production Systems ◽  
Bell Pepper ◽  
Root Tip ◽  
Root Weight ◽  
Plant Mortality ◽  
Fresh Market ◽  
Plant Weight ◽  
Pathogenicity Tests ◽  
Pepper Plants

Ten species of Pythium and a group of isolates that produced filamentous sporangia but did not form sexual structures (Pythium ‘group F’) were recovered from the root systems of fresh market bell pepper plants grown on polyethylene-mulched production systems in Florida. Pathogenicity tests using pasteurized field soil inoculated with infested wheat seed demonstrated that P. aphanidermatum, P. myriotylum, P. helicoides, and P. splendens can cause significant root rot and reductions in root growth of pepper. P. aphanidermatum and P. myriotylum caused the most severe root rot, the greatest reductions in plant weight, and 42 and 62% plant mortality, respectively. In pathogenicity tests with tomato plants, these four species produced similar plant weight losses and disease ratings to those observed in pepper, but little or no plant mortality. Low incidences of root tip necrosis in pepper plants were observed with P. arrhenomanes, P. catenulatum, P. graminicola, and P. irregulare, but none of these species caused losses in root weight and only P. irregulare reduced shoot weight. P. periplocum, P. spinosum, and Pythium sp. F colonized root tissue of pepper but caused no significant root rot and did not adversely affect growth. Similar trends were observed with tomato, except that P. arrhenomanes caused limited root tip necrosis without affecting plant growth and P. catenulatum, P. graminicola, P. irregulare, P. spinosum, and Pythium sp. F colonized at least some of the plants but did not cause root disease. A significant interaction between temperature and P. aphanidermatum or P. myriotylum was observed on pepper transplants. The greatest reductions in growth occurred at 28°C, whereas plant mortality only occurred at 34°C.

scholarly journals Evaluating the Impact of Transplanting Depth on Bell Pepper Growth and Yield

HortScience ◽  
1994 ◽  
Vol 29 (10) ◽  
pp. 1133-1135 ◽  
Author(s):  
Charles S. Vavrina ◽  
Kenneth D. Shuler ◽  
Phyllis R. Gilreath
Keyword(s):  
Soil Temperature ◽  
Leaf Area ◽  
Bell Pepper ◽  
Growth And Yield ◽  
Plant Weight ◽  
Stand Establishment ◽  
Competitive Edge ◽  
Number Of Leaves ◽  
The Impact ◽  
Pepper Plants

`Jupiter' and `Verdel' bell pepper (Capsicum annuum L.) transplants set to the depth of cotyledon leaves or to the first true leaf yielded more fruit than transplants set to the top of the rootball. Increased yields and early stand establishment criteria (number of leaves, leaf area, plant weight, and plant height) suggest that planting pepper transplants deeper than is now common is commercially beneficial in Florida. Deeper plantings may place pepper roots in a cooler environment and reduce fluctuations in soil temperature. Moderated soil temperature, in conjunction with earlier fertilizer and water acquisition, may give deeper-planted pepper plants a competitive edge in growth.

scholarly journals Effect of Rhizobium Strains and Biofertilizers on Foot, Root Rot and Yield of Bush Bean in Sclerotinia sclerotiorum Infested Soil

1970 ◽  
Vol 16 ◽  
pp. 73-78 ◽  
Author(s):  
KM Khalequzzaman ◽  
I Hossain
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Root Rot ◽  
Plant Root ◽  
Root Weight ◽  
Infested Soil ◽  
Plant Vigour ◽  
Plant Weight ◽  
Rhizobium Strains ◽  
Bush Bean ◽  
Pot Trials

A glasshouse experiment was carried out to find out the effect of Rhizobium strains and biofertilizers on foot and root rot (Sclerotinia sclerotiorum) and yield of Bush bean. Six Rhizobium strains and three biofertilizers were used for seed treatment. Rhizobium strains (BINAR P36 and BINAR P6) and BINA biofertilizer resulted maximum reduction of seed rot, and foot and root rot of Bush bean in pot. In addition, these treatments increased germination, plant stand, shoot length/plant, root length/plant, shoot weight/plant, root weight/plant, vigour index, plant height, number of green pods/plant, weight of green pods/plant, weight of seeds/plant and healthy looking seeds in pot trials. Among them Rhizobium strains (BINAR P36) showed best performance. Key words: Rhizobium, biofertilizer, foot and root rot, Sclerotinia sclerotiorum, yield, Bush bean.   DOI:10.3329/jbs.v16i0.3744 J. bio-sci. 16: 73-78, 2008

scholarly journals Comparative Performance of Fungicides, Biofungicides, and Host Plant Defense Inducers in Suppression of Phytophthora Root Rot in Flowering Dogwood During Simulated Root Flooding Events

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1703-1711 ◽  
Author(s):  
Matthew S. Brown ◽  
Fulya Baysal-Gurel ◽  
Jason B. Oliver ◽  
Karla M. Addesso
Keyword(s):  
Plant Defense ◽  
Host Plant ◽  
Disease Severity ◽  
Root Rot ◽  
Positive Control ◽  
Root Weight ◽  
Phytophthora Root Rot ◽  
Plant Weight ◽  
Flowering Dogwood ◽  
Flooding Events

During flooding events in nurseries, Phytophthora root rot caused by Phytophthora cinnamomi Rands often causes damage that leads to complete crop loss. In this study, we evaluated the efficacy of fungicides, biofungicides, and host plant defense inducers for preventive and curative control of Phytophthora root rot on flowering dogwood (Cornus florida L.) seedlings exposed to a simulated flood event of 1, 3, or 7 days. In two greenhouse trials, preventive (7 days before flooding) or curative (1 day after flooding) drench treatments were applied to dogwood seedlings artificially inoculated with P. cinnamomi. The plants were flooded by maintaining standing water for 1, 3, or 7 days. After the trials, plant growth data (total plant weight, root weight, plant height, and plant width) were recorded, and root systems were assessed for disease severity using a scale of 0 to 100% of roots affected, and subsamples were plated on PARPH-V8 medium to determine the percent recovery of the Phytophthora pathogen. Plants preventively treated with Subdue MAXX had reduced disease severity relative to the nontreated, inoculated plants (positive control) flooded 1, 3, or 7 days in both trials. Pageant Intrinsic and Segovis treatments also had lower disease severity than the positive control at all flooding durations in trial two, but not trial one. In trial one, preventive and curative treatments of Orkestra Intrinsic had reduced disease severity compared with the positive control at 1 and 3 days of flooding, whereas curative treatments of Empress Intrinsic and Tartan Stressgard also were effective at 1 and 3 days of flooding in trial one. The host plant defense inducers (Aliette 80 WDG, Signature Xtra, and Actigard) were inconsistent and ineffective at reducing disease severity when applied as preventive or curative treatments. Preventive treatments of the biofungicides RootShield Plus+and MBI-110 had consistently lower disease severity than the positive control at 1 day of flooding but not 3 or 7 days of flooding. Potentially, growers can use information from this study to manage Phytophthora root rot during flooding or in areas of the nursery that often experience high soil moisture levels.

scholarly journals Effectiveness of Nine Different Fungicides for Management of Crown and Root Rot of Chile Pepper Plants Caused by Phytophthora capsici

2015 ◽  
Vol 16 (4) ◽  
pp. 218-222 ◽  
Author(s):  
Michael E. Matheron ◽  
Martin Porchas
Keyword(s):  
Root Rot ◽  
Phytophthora Capsici ◽  
Field Trials ◽  
Pepper Plant ◽  
Plant Mortality ◽  
Phytophthora Blight ◽  
Chile Pepper ◽  
Fungicide Application ◽  
Crown And Root Rot ◽  
Pepper Plants

Bell and chile pepper plants are affected by the economically important disease Phytophthora blight, which is caused by the oomycete pathogen Phytophthora capsici. Greenhouse and field trials were conducted to evaluate and compare the ability of nine different fungicides to reduce development of the crown and root rot phase of Phytophthora blight and the resulting chile pepper plant death when applied at 2- and 4-week intervals. Overall, chile pepper plant mortality was significantly decreased in three greenhouse trials with soil applications of fungicide products containing ametoctradin + dimethomorph, cyazofamid, dimethomorph, ethaboxam, fluazinam, fluopicolide, mandipropamid, mefenoxam, and oxathiapiprolin. The same fungicides, excluding mandipropamid and oxathiapiprolin, also significantly reduced overall plant mortality in two field trials. No significant difference was found between 2- and 4-week fungicide application intervals with respect to chile pepper plant survival in any greenhouse or field trial. In general, the degree of reduction in chile pepper plant mortality was lower in field compared to greenhouse trials, probably due to the respective soil surface spray compared to soil drench method of fungicide application used in each instance. Accepted for publication 17 November 2015. Published 30 November 2015.

scholarly journals First Report of Hypocotyl and Root Rot Disease Caused by Pythium deliense on Soybean Sprouts in Korea

Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1399-1399 ◽  
Author(s):  
S.-C. Yun ◽  
J.-W. Kim
Keyword(s):  
Root Rot ◽  
Production Systems ◽  
Brown Rot ◽  
Centraalbureau Voor ◽  
First Report ◽  
Root Rot Disease ◽  
Soybean Sprouts ◽  
Pathogenicity Tests ◽  
Genus Pythium ◽  
Rot Disease

Soybean (Glycine max Merr.) sprouts have been a traditional Korean food for at least 1,000 years. During the summers of 2000 and 2001, severe hypocotyl and root rot occurred on fully grown soybean sprouts, especially in commercial recirculating mass production systems. Brown rot on water-soaked hypocotyls and roots of soybean sprouts caused a 10 to 20% loss in production yield. To investigate the cause, 180 sections of tissue were surface sterilized for 30 s in 75% ethanol and plated on potato dextrose agar (PDA). A fungus with white, aerial mycelia and cultural characteristics of Pythium sp. was isolated consistently. The fungal isolates were identified as Pythium deliense Meurs based on various mycological characteristics (2) on corn meal agar (CMA) and sucrose-asparagine bentgrass leaf culture medium (1). P. deliense oogonia were spherical, smooth, 19 to 23 μm in diameter, and their stalks bent toward the antheridia. The antheridia were the shape of a straw hat, curved club-shaped, terminal or intercalary, monoclinous, occasionally diclinous, 12 to 15 × 8 to 11 μm, and 1 per oogonium (2). In pathogenicity tests, soybean sprouts and the fungus were cultured simultaneously in containers (30 × 30 × 50 cm [W × L × H]) with a daily 3-h showering period at 25°C. There were 8,000 to 10,000 seeds per container inoculated with four plugs of agar inoculum (2 × 2 cm). Inoculum was prepared from 5-day-old fungal cultures grown on PDA. After 6 days, the inoculated soybean sprouts showed the same symptoms as described above, whereas the noninoculated sprouts remained healthy. The fungal pathogen was reisolated from all the inoculated sprouts. P. deliense has never been reported as a pathogen of soybean sprouts. To our knowledge, this is the first report of hypocotyl and root rot disease caused by Pythium deliense on soybean sprout in Korea. References: (1) J.-W. Kim and E.-W. Park. Kor. J. Mycology 25:276, 1997. (2) A. J. Van der Plaatis-Niterink. Monograph of the genus Pythium. Vol. 21, Studies in Mycology. Centraalbureau voor Schimmelcultures, Inst. R. Neth. Acad. Sci. Lett. The Netherlands, 1981.

Hydramulch for Muskmelon and Bell Pepper Crop Production Systems

2006 ◽  
Vol 12 (2) ◽  
pp. 39-55 ◽  
Author(s):  
Joe P. Warnick ◽  
Carlene A. Chase ◽  
Erin N. Rosskopf ◽  
Johannes M. Scholberg ◽  
Eric H. Simonne ◽  
...  
Keyword(s):  
Crop Production ◽  
Production Systems ◽  
Bell Pepper

scholarly journals Evaluation of Trichoderma harzianum for controlling root rot caused by Phytophthora capsici in pepper plants

1999 ◽  
Vol 48 (1) ◽  
pp. 58-65 ◽  
Author(s):  
A. Sid Ahmed ◽  
C. Perez-Sanchez ◽  
C. Egea ◽  
M. E. Candela
Keyword(s):  
Trichoderma Harzianum ◽  
Root Rot ◽  
Phytophthora Capsici ◽  
Pepper Plants

scholarly journals First Report of Pythium Root Rot of Rau Ram (Polygonum odoratum)

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 340-340
Author(s):  
E. N. Rosskopf ◽  
C. B. Yandoc ◽  
B. Stange ◽  
E. M. Lamb ◽  
D. J. Mitchell
Keyword(s):  
Root Rot ◽  
Vascular System ◽  
Pond Water ◽  
Centraalbureau Voor ◽  
First Report ◽  
Pathogenicity Tests ◽  
Symptomatic Tissue ◽  
Pythium Helicoides ◽  
Production House ◽  
Test Plants

Polygonum odoratum (= Persicaria odorata), known as rau ram or sang hum, is native to southeastern Asia and is a common herb in Vietnamese cuisine (1). It has been studied most extensively for its aromatic compound content (2). In Florida, rau ram commonly is grown hydroponically in greenhouses using large, cement beds with recirculated water. The plants form dense mats from which new growth is trimmed for market. During January of 2002, a severe dieback was observed in one production house in Saint Lucie County, FL. Plants with less severe symptoms were yellowed and stunted. Roots of symptomatic plants were largely decayed with root symptoms beginning as a tip necrosis. The cortex of severely affected roots slipped off easily, leaving a stringy vascular system. Plating of symptomatic tissue from 20 randomly selected plant samples was performed with multiple general and selective media including potato dextrose agar, corn meal agar with pimaricin, ampicillin, rifampicin, and pentachloronitrobenzene (PARP) (3). All colonies produced were identified as Pythium helicoides Drechsler on the basis of sporangial, oogonial, and antheridial characteristics (4). Isolates had proliferous, obovoid, papillate sporangia, and were homothallic with smooth-walled oogonia and thick-walled, aplerotic oospores. Multiple antheridial attachments per oogonium were common with the antheridium attached along its entire length. Pathogenicity tests were conducted using P. odoratum plants grown from commercial transplants. Two tests were performed. Each test was conducted using eight inoculated and eight control plants. In the first test, plants were maintained in 10-cm pots immersed in sterilized pond water for the duration of the test. Plants were inoculated with five 7- × 70-mm sections of freshly growing mycelial culture per plant using 10-day-old cultures of Pythium helicoides grown on water agar. Chlorosis was observed at approximately 2 months after inoculation. Root necrosis was observed in inoculated plants approximately 5 months after inoculation. This test was performed in the greenhouse with temperatures ranging from 20 to 30°C. The second test was performed in growth chambers at 35 to 40°C. Plants were maintained in 10-cm pots immersed in Hoagland's solution and were inoculated with four 6-mm plugs per plant. Symptoms were observed on inoculated plants at this temperature within 1 week of inoculation. No chlorosis or root decay was observed in noninoculated, immersed plants. The pathogen was reisolated from inoculated, symptomatic tissue. To our knowledge, this is the first report of root rot of P. odoratum caused by Pythium helicoides. References: (1) R. E. Bond. Herbarist 55:34, 1989. (2) N. X. Dung et al. J. Essent. Oil Res. 7:339, 1995. (3) M. E. Kannwischer and D. J. Mitchell. Phytopathology 68:1760, 1978. (4) A. J. van der Plaats-Niterink. Monograph of the Genus Pythium. Vol. 21, Studies in Mycology. Centraalbureau voor Schimmelcutltures, Baarn, The Netherlands, 1981.

A single residue in the 126-kDa protein of pepper mild mottle virus controls the severity of symptoms on infected green bell pepper plants

2009 ◽  
Vol 154 (3) ◽  
pp. 489-493 ◽  
Author(s):  
T. U. Ichiki ◽  
E. N. Nagaoka ◽  
K. Hagiwara ◽  
T. Sasaya ◽  
T. Omura
Keyword(s):  
Bell Pepper ◽  
Mottle Virus ◽  
Pepper Mild Mottle Virus ◽  
Pepper Plants

scholarly journals Temperature, Moisture, and Seed Treatment Effects on Rhizoctonia solani Root Rot of Soybean

Plant Disease ◽  
2003 ◽  
Vol 87 (5) ◽  
pp. 533-538 ◽  
Author(s):  
A. E. Dorrance ◽  
M. D. Kleinhenz ◽  
S. A. McClure ◽  
N. T. Tuttle
Keyword(s):  
Soil Moisture ◽  
Rhizoctonia Solani ◽  
Root Rot ◽  
Seed Treatment ◽  
Anastomosis Group ◽  
Control Measures ◽  
Root Weight ◽  
Wide Range ◽  
Plant Stand ◽  
Growth Chamber Studies

The effects of temperature and soil moisture on infection and disease development by Rhizoctonia solani on soybean were studied individually. In addition, the anastomosis group of R. solani isolates recovered from soybean from 35 fields in 15 counties was determined. All of the 44 isolates recovered in this study were AG-2-2 IIIB. Five isolates of R. solani were able to infect and colonize soybean roots and hypocotyls at 20, 24, 28, and 32°C in growth chamber studies. The temperatures evaluated in this study were not limiting to the isolates tested. In greenhouse studies, nine R. solani isolates and a noninoculated control were evaluated at 25, 50, 75, and 100% soil moisture holding capacity (MHC). Root weights were greater and percent stand averages higher at 50 and 75% than at 25 or 100% MHC; however, as percentage of control, the main effect on percent moisture for percent stand, plant height, or root weight was not significant. There were significant differences among the isolates for the percent stand, root rot rating, and root fresh weight of soybean in each study. In both temperature and moisture studies, the R. solani isolates could be separated as predominantly causing (i) seed rot, as detected by greatly reduced plant stand; (ii) root rot generally having no effect on plant stand but a high root rot rating and low root weight; or (iii) hypocotyl lesions, having no effect on plant stand, a low root rot score, and a high number of red lesions on the hypocotyl. In the greenhouse seed treatment evaluations of five fungicides, there was no fungicide by isolate interaction using these pathogenic types of R. solani. None of the seed treatments evaluated in this study provided 100% control of the four isolates tested. Due to the wide range of environmental factors that permit R. solani infection and disease on soybeans, other control measures that last all season, such as host resistance, should be emphasized.

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