Evaluation of some fungicides for seed treatment and foliar application in management of damping-off of seedlings and blight of rapeseed caused by Alternaria brassicae

1990 ◽  
Vol 110 (3) ◽  
pp. 163-167 ◽  
Author(s):  
Nisar A. Ansari ◽  
M. Wajid Khan ◽  
A. Muheet
Keyword(s):  
Seed Treatment ◽  
Foliar Application ◽  
Alternaria Brassicae ◽  
Damping Off

Exploring seed treatment and foliar application of fungicides on management of Pea diseases

2021 ◽  
Vol 29 (3) ◽  
pp. 226-230
Author(s):  
Sanjay Kharte ◽  
Pramod Kumar Gupta ◽  
Yogita Gharde
Keyword(s):  
Seed Treatment ◽  
Foliar Application

Influence of previous crops and fungicide seed treatment in the incidence and control of damping-off caused by Rhizoctonia solani in cotton seedlings under greenhouse conditions

2021 ◽  
Vol 47 (3) ◽  
pp. 157-161
Author(s):  
Augusto César Pereira Goulart
Keyword(s):  
Rhizoctonia Solani ◽  
Cover Crops ◽  
Seed Treatment ◽  
Integrated Management ◽  
Substrate Surface ◽  
Damping Off ◽  
Crotalaria Juncea ◽  
Mato Grosso ◽  
Forage Sorghum ◽  
And Control

ABSTRACT The aim of this study was to verify the influence of previous crops and fungicide seed treatment in the incidence and control of damping-off caused by Rhizoctonia solani in cotton seedlings under greenhouse conditions. This experiment was carried out during two years at Embrapa Western Agriculture, in Dourados, Mato Grosso do Sul State, Brazil. In addition to cotton (treated and untreated seeds) and fallow, the following cover crops were tested as previous crops: black oats, millet, corn, forage sorghum, soybean, common beans, crotalaria (Crotalaria juncea), brachiaria (Urochloa ruziziensis) and brachiaria (Urochloa ruziziensis) + crotalaria (Crotalaria juncea). The fungicide mixture used as treatment to cotton seeds was triadimenol + pencycuron + tolylfluanid (50 + 50 + 30 g a.i./100 kg seeds). Seeds from cotton and previous crops were sown in soil contained in plastic trays and pots; the seeds were placed in individual and equidistant 3cm-deep wells. Inoculation of R. solani was obtained by homogeneously distributing the fungal inoculum onto the substrate surface (2.5g/tray and 0.34g/pot). The fungus was grown for 35 days on autoclaved black oat seeds subsequently ground to powder using a mill (1mm). Damping-off was daily evaluated from the seventh day after sowing. There was a significant effect of the interaction previous crops x fungicide treatment (P<0.05). The fungicide seed treatment was efficient in controlling seedling damping-off caused by R. solani and its effect was potentiated when grasses were the previous crops. Use of grasses such as brachiaria (Urochloa ruziziensis), black oats, millet, corn and forage sorghum as previous crops, besides fallow, significantly contributed to a smaller R. solani population in the soil, which resulted in lower rates of cotton seedling damping-off. On the other hand, using cotton continuously, as well as the legumes soybeans, beans, crotalaria (Crotalaria juncea), and brachiaria (Urochloa ruziziensis) + crotalaria (Crotalaria juncea) as previous crops to cotton, was consistently associated with higher rates of seedling damping-off, contributing to the increase or at least the maintenance of R. solani inoculum in the soil. The highest damping-off percentages were observed in plots under continuous cotton cultivation without fungicide seed treatment. The present results reinforce the need of improving damping-off control in cotton seedlings by adopting integrated management programs in areas infested with R. solani.

scholarly journals The Efficacy of Ethaboxam as a Soybean Seed Treatment Toward Phytophthora, Phytopythium, and Pythium in Ohio

Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1421-1432 ◽  
Author(s):  
Kelsey Scott ◽  
Meredith Eyre ◽  
Dair McDuffee ◽  
Anne E. Dorrance
Keyword(s):  
Seed Treatment ◽  
Soybean Seed ◽  
Primary Objective ◽  
Phytophthora Species ◽  
Damping Off ◽  
Seed Treatments ◽  
Seedling Disease ◽  
Seed Decay ◽  
Fungicide Mixtures ◽  
Seed Rot

Phytophthora, Phytopythium, and Pythium species that cause early-season seed decay and pre-emergence and post-emergence damping off of soybean are most commonly managed with seed treatments. The phenylamide fungicides metalaxyl and mefenoxam, and ethaboxam are effective toward some but not all species. The primary objective of this study was to evaluate the efficacy of ethaboxam in fungicide mixtures and compare those with other fungicides as seed treatments to protect soybean against Pythium, Phytopythium, and Phytophthora species in both high-disease field environments and laboratory seed plate assays. The second objective was to evaluate these seed treatment mixtures on cultivars that have varying levels and combinations of resistance to these soilborne pathogens. Five of eight environments received adequate precipitation in the 14 days after planting for high levels of seedling disease development and treatment evaluations. Three environments had significantly greater stands, and three had significantly greater yield when ethaboxam was used in the seed treatment mixture compared with treatments containing metalaxyl or mefenoxam alone. Three fungicide formulations significantly reduced disease severity compared with nontreated in the seed plate assay for 17 species. However, the combination of ethaboxam plus metalaxyl in a mixture was more effective than either fungicide alone against some Pythium and Phytopythium species. Overall, our results indicate that the addition of ethaboxam to a fungicide seed treatment is effective in reducing seed rot caused by these pathogens commonly isolated from soybean in Ohio but that these effects can be masked when cultivars with resistance are planted.

scholarly journals Seed Treatment with Phosphonate (AG3) Suppresses Pythium Damping-off of Cucumber Seedlings

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 459-464 ◽  
Author(s):  
P. A. Abbasi ◽  
G. Lazarovits
Keyword(s):  
Seed Treatment ◽  
Sandy Loam ◽  
Cost Effective ◽  
Controlled Environment ◽  
Damping Off ◽  
Untreated Seed ◽  
Cucumis Sativus L ◽  
Muck Soil ◽  
Treated Seed ◽  
Loam Soil

A formulation of phosphonate (AG3) was tested as a seed treatment for the control of Pythium damping-off of cucumber (Cucumis sativus L.) plants under controlled environment and field conditions. Cucumber seed were treated by soaking for 10 min in phosphonate solution. They were then planted into peat-based mix or sandy-loam soil mixed with Pythium aphanidermatum or P. ultimum inoculum or into muck soil naturally infested with P. irregulare, P. ultimum, and other Pythium spp. Under growth-room conditions, phosphonate seed treatment provided more than 80% control of damping-off in all infested substrates tested. Effective disease control was obtained even when treated seed were stored for 5 weeks and up to 18 months prior to planting. In microplots containing naturally infested muck soil, phosphonate seed treatment decreased the percentage of diseased cucumber plants and increased total fresh weights compared with untreated seed and phosphonate post-planting drench. In field-plot tests 6 weeks after planting treated seed in Pythium-infested muck soil, cucumber stands were 63% compared with 18% in the control, which had no phosphonate exposure, and 53% in the post-planting drench. Tests for potential phytotoxicity in the greenhouse showed that radish and bok choy germination was reduced by phosphonate treatment but corn, cucumber, soybean, sugar beet, tomato, and wheat were not affected. Phosphonate seed treatment is a cost-effective way of protecting cucumber plants from Pythium damping-off.

Biological control of damping-off of sugar-beet and cotton with Chaetomium globosum or a fluorescent Pseudomonas sp.

1988 ◽  
Vol 34 (5) ◽  
pp. 631-637 ◽  
Author(s):  
D. Walther ◽  
D. Gindrat
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Seed Treatment ◽  
Pythium Ultimum ◽  
Chaetomium Globosum ◽  
Pseudomonas Sp ◽  
Damping Off ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

Seed treatment with ascospores of Chaetomium globosum reduced damping-off of sugar-beet caused by seed-borne Phoma betae and soil-borne Pythium ultimum or Rhizoctonia solani in growth chamber experiments. Seed treatment with a fluorescent Pseudomonas sp. controlled Ph. betae and P. ultimum but not R. solani. Coating cotton seeds with ascospores controlled P. ultimum and R. solani damping-off. In some experiments, biological seed treatments were equally or more effective than seed treatment with captan. However, greater variability in disease control occurred with the antagonists than with captan. Fifty percent of freshly harvested ascospores of C. globosum germinated in 8 h on water agar. When ascospores were stored under air-dried conditions for 3 days to 2.5 years, germination increased to > 90%. Under same storage conditions, survival of Pseudomonas sp. was detected after 4 months. Antagonistic activities observed in vitro were hyphal coiling of C. globosum on R. solani, and mycostasis was induced by C. globosum or Pseudomonas sp. on agar and soil. The presumed cause of mycostasis is the diffusible antifungal metabolites which may also be involved in the biological control of damping-off.

scholarly journals Pythium, Phytophthora, and Phytopythium spp. Associated with Soybean in Minnesota, Their Relative Aggressiveness on Soybean and Corn, and Their Sensitivity to Seed Treatment Fungicides

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 62-72 ◽  
Author(s):  
L. Radmer ◽  
G. Anderson ◽  
D. M. Malvick ◽  
J. E. Kurle ◽  
A. Rendahl ◽  
...  
Keyword(s):  
Root Rot ◽  
Temperature Effects ◽  
Seed Treatment ◽  
Soil Samples ◽  
Damping Off ◽  
Seedling Disease ◽  
Strobilurin Fungicides ◽  
Seed Decay ◽  
Reference Sequences ◽  
Information Database

Pythium spp. cause seed decay, damping-off, and root rot in soybean and corn; however, their diversity and importance as pathogens in Minnesota are unknown. Our objectives were to identify the Pythium spp. present in Minnesota soybean fields, determine their aggressiveness on corn and soybean, and investigate their sensitivity to seed treatment fungicides. For identification, sequences obtained using internal transcribed space ITS4 and ITS1 primers were compared with reference sequences in the National Center for Biotechnology Information database. Seedling and soil samples yielded over 30 oomycete species. Aggressiveness was determined using two methods; a seed assay, which also examined temperature effects on aggressiveness, and a seedling assay. Of 21 species evaluated, seven Pythium spp. were pathogenic on both soybean and corn, reducing root growth by 20% or more while two Pythium and one Phytopythium spp. were pathogenic only on soybean. Aggressiveness of many isolates increased as temperature increased from 15°C to 25°C. The sensitivity of 10 pathogenic species to azoxystrobin, ethaboxam, mefenoxam, pyraclostrobin, or trifloxystrobin was tested. EC50 values for mefenoxam and ethaboxam were 10−2 of those to strobilurin fungicides. Pythium spp. in Minnesota are diverse and a significant cause of seedling disease on soybean and corn. Most Pythium spp. isolated in this study were more sensitive to mefenoxam and ethaboxam than to strobilurin fungicides.

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