EFFECTS OF FLOODING, SOIL FUMIGATION, AND COMPOSTED ORGANIC HOUSEHOLD WASTE ON PYTHIUM ROOT ROT IN BULBOUS IRIS

1997 ◽  
pp. 587-590
Author(s):  
G.J. van Os ◽  
W.J.M. van Gulik ◽  
J.P.M. Wijnker
Keyword(s):  
Root Rot ◽  
Soil Fumigation ◽  
Household Waste ◽  
Pythium Root Rot

scholarly journals Yield Responses of Direct-Seeded Wheat to Rhizobacteria and Fungicide Seed Treatments

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 780-784 ◽  
Author(s):  
R. James Cook ◽  
David M. Weller ◽  
Adel Youssef El-Banna ◽  
Dan Vakoch ◽  
Hao Zhang
Keyword(s):  
Spring Wheat ◽  
Root Rot ◽  
Soil Fumigation ◽  
Seed Treatments ◽  
Root Diseases ◽  
Pythium Root Rot ◽  
Rhizoctonia Root Rot ◽  
Direct Seeded ◽  
Yield Responses ◽  
Take All

Field trials were conducted with winter and spring wheat in eastern Washington and northern Idaho over several years to determine the benefit, as measured by grain yield, of seed treatments with rhizobacteria and formulated fungicides in cropping systems favorable to root diseases. The trials were conducted with wheat direct-seeded (no-till) in fields with a history of intensive cereals and one or more of the root diseases: take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8 and R. oryzae, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum. The seed treatments included Bacillus sp. L324-92, Pseudomonas fluorescens Q69c-80, Pseudomonas fluorescens Q8r1-96, difenoconazole + metalaxyl (Dividend + Apron), difenoconazole + mefenoxam (Dividend + Apron XL = Dividend XL), tebuconazole + metalaxyl (Raxil XT), and tebuconazole + thiram (Raxil-thiram). Controls were nontreated seed planted into both nontreated (natural) soil and soil fumigated with methyl bromide just prior to planting. Although the data indicate a trend in higher wheat yields with two rhizobacteria treatments over the nontreated control (171 and 264 kg/ha, respectively), these higher yields were not significantly different from the nontreated control (P = 0.06). Fungicide seed treatments alone similarly resulted in yields that were 100 to 300 kg/ha higher than the nontreated control, but only the yield responses to Dividend on winter wheat (289 kg/ha) and Dividend + Apron on spring wheat (263 kg/ha) were significant (P ≤ 0.05). The greatest yield increases over the nontreated control occurred with certain rhizobacteria-fungicide combinations, with three treatments in the range of 312 to 486 kg/ha (6.1 to 17.7%; P ≤ 0.05). Some rhizobacteria-fungicide combinations brought average yields to within 85 to 90% of those obtained with soil fumigation. Only soil fumigation produced a measurable reduction in the incidence of take-all and Rhizoctonia root rot, as assessed on washed roots. No reliable method exists for visual quantification of Pythium root rot on wheat.

Identification of metalaxyl and ethaboxam insensitive Pythium sylvaticum pathogenic to pulse crops in Montana, USA.

2021 ◽  
Author(s):  
Lipi Parikh ◽  
Swarnalatha Moparthi ◽  
Frankie Crutcher ◽  
Mary Burrows
Keyword(s):  
Root Rot ◽  
Damping Off ◽  
Management Options ◽  
Fungicide Sensitivity ◽  
Root Rots ◽  
Pulse Crops ◽  
Pythium Root Rot ◽  
Pythium Sylvaticum ◽  
Potential Pathogenicity

Pythium root rot and damping-off caused by Pythium spp. are important diseases of pulse crops. In a 2016 pathogen survey from dry pea growing fields in Montana, along with commonly known causal agents P. ultimum and P. irregulare, an isolate identified as P. sylvaticum (LPPY17) was isolated from the rhizosphere of a diseased pea plant collected from Valley County, MT. Root rots and damping-off caused by P. sylvaticum have not previously been reported for chickpea, pea, and lentil crops. The isolate LPPY17 was tested for fungicide resistance in vitro, and results indicated a reduced sensitivity to metalaxyl and ethaboxam containing fungicides. LPPY17 was also tested for pathogenicity on chickpea, pea, and lentil seedlings in the greenhouse, and the results from the study revealed LPPY17 is capable of causing both root rots and damping off. Due to the potential pathogenicity and reduced fungicide sensitivity of this species, in the future it will be important to monitor for P. sylvaticum in pulse root rot surveys and diagnostics, as management options may be different from other common Pythium spp.

STUDIES ON BROWNING ROOT ROT OF CEREALS: VI. FURTHER CONTRIBUTIONS ON THE EFFECTS OF VARIOUS SOIL AMENDMENTS ON THE INCIDENCE OF THE DISEASE IN WHEAT

1940 ◽  
Vol 18c (6) ◽  
pp. 240-257 ◽  
Author(s):  
T. C. Vanterpool
Keyword(s):  
Root Rot ◽  
Nutrient Deficiencies ◽  
Sweet Clover ◽  
Poor Growth ◽  
Prairie Soils ◽  
Pythium Root Rot ◽  
The Poor ◽  
Copper Manganese ◽  
Supplemental Nutrients ◽  
Severe Leaf

Further work has substantiated earlier findings that phosphatic fertilizers and farm manure will give adequate control of Pythium root rot of wheat in infested prairie soils. The improvement in growth resulting from these amendments is considered to be due to the production of a larger number of quicker growing roots which lessens the chances for infection and leaves more roots healthy, though the same percentage may be affected as in diseased plants showing severe leaf discolorations. Experiments have failed to indicate that the phosphatic materials increase resistance appreciably. Nitrogenous materials when applied singly had virtually no effect on growth, but once ample phosphorus was added, further nitrogen applications gave substantially greater increases than phosphate alone. Phosphorus is apparently the chief limiting element. No difference was found in preliminary tests in the phosphate-fixing power of browning and normal soils. Typical browning soils responded irregularly to small applications of boron, copper, manganese, or zinc, but were not found to be seriously lacking in these elements. Moderate benefits resulted from heavy applications of gypsum and of sulphur. Browning soil was found also to be deficient in phosphate for non-cereals such as alfalfa, buckwheat, carrots, flax, lettuce, and sweet clover. These crops were not attacked by the Pythium spp. pathogenic to cereals. Consequently the poor growth of the non-cereals in browning soil appears to be due to nutrient deficiencies, while the poor growth of cereals is due to both root-destroying fungi and nutrient deficiencies. In both instances phosphorus is probably the chief limiting element. Ground cereal straw, sweet clover hay, and weed hay amendments gave moderate increases m the growth of wheat. No consistent differences were found in the carbon-nitrogen ratios of browning and normal soils. The results as a whole suggest that two of the most practicable means of meeting the browning root-rot situation are, firstly, to supply supplemental nutrients in the form of artificial fertilizers, and secondly, to add organic residues or farm manure regularly to fields subject to the disease.

Sanitation of Float Trays for the Management of Pythium Species in Tobacco Float Systems

2020 ◽  
Vol 21 (1) ◽  
pp. 21-25
Author(s):  
Lindsey D. Thiessen ◽  
Grant H. Ellington ◽  
Justin A. Macialek ◽  
Chuck S. Johnson ◽  
David T. Reed
Keyword(s):  
Root Rot ◽  
Pythium Species ◽  
Greenhouse Production ◽  
Pythium Root Rot ◽  
Tobacco Seedlings ◽  
Agricultural Use ◽  
Phase Out ◽  
Disease Free ◽  
Important Disease ◽  
H 30

Pythium root rot is an economically important disease threatening greenhouse production of tobacco seedlings. Although methyl bromide was historically used for tray sanitation, the phase-out of the fumigant from agricultural use has left few options for growers to produce disease-free transplants. Steam sanitation at 80°C for 30 min has shown control of disease caused by Rhizoctonia solani and has been adopted for use to manage Pythium spp. This study evaluates other steam temperatures and time durations to effectively manage Pythium spp. in float-tray systems. Naturally infested trays steamed at 63, 71, and 77°C for 30 min significantly reduced Pythium spp. from trays compared with TriSan wash and CC-15 dip treatments. Float trays inoculated with Pythium spp. that were steamed at 70 and 80°C for 2 h 30 min, respectively, also significantly reduced Pythium spp. survival. Other fungi, likely saprophytic or beneficial organisms, were not significantly impacted by any steaming treatment.

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