scholarly journals Beneficial Effects of Solid Matrix Chemo-priming in Okra

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 535-537 ◽  
Author(s):  
K. E. Conway ◽  
R. Mereddy ◽  
B. A. Kahn ◽  
Y. Wu ◽  
S. W. Hallgren ◽  
...  
Keyword(s):  
Untreated Control ◽  
Seed Treatment ◽  
Seedling Emergence ◽  
Pythium Ultimum ◽  
Field Trials ◽  
Solid Matrix ◽  
Damping Off ◽  
Untreated Seed ◽  
Beneficial Effects ◽  
Emergence And Reduction

Two field trials at Stillwater and Bixby, OK, evaluated the efficacy of solid matrix priming techniques, alone or in combination with fungicide seed treatment on seedling emergence and reduction of damping-off of okra in field soil naturally infested with Pythium ultimum. The following treatments were evaluated: thiram + carboxin (chemo-primed) (commercially applied), biological seed treatment (bio-primed) (Trichoderma harzianum isolate OK-110, 1 g suspended in 1% carboxymethylcellulose [CMC]), untreated seed (control), and a 1% CMC control. Chemo-primed seeds had a more uniform and faster emergence compared with untreated seeds at both field sites. Within 3 days, 92 and 78% of chemo-primed seeds had emerged at Stillwater and Bixby, respectively, compared with 84 and 71% emergence in the untreated control. Mean emergence of chemo-primed seeds was lower (P ≤ 0.05) than the untreated control. Chemo-primed seeds had greater vigor (P≤ 0.05) at both locations compared with either fungicide-treated or priming alone, at both locations. There were no differences (P ≤ 0.05) in yield among treatments at both locations. P. ultimum was consistently isolated from damped-off seedlings and surrounding soil at both locations. Isolates of P. ultimum were more pathogenic on okra in laboratory tests than isolates of Rhizoctonia spp., Fusarium spp., and other Pythium spp. also isolated from seed or soil.

scholarly journals FIELD PERFORMANCE OF BIO-PRIMING FOR PROTECTION OF sh2 SWEET CORN FROM PREEMERGENCE DAMPING-OFF CAUSED BY PYTHIUM ULTIMUM.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1110f-1110
Author(s):  
Nancy W. Callan ◽  
James B. Miller ◽  
Don E. Mathre
Keyword(s):  
Pseudomonas Fluorescens ◽  
Seed Treatment ◽  
Field Experiments ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Field Performance ◽  
Pythium Ultimum ◽  
Damping Off ◽  
Corn Seed ◽  
Seed Bacterization

Shrunken-2 supersweet (sh2) sweet corn is susceptible to preemergence damping-off caused by Pythium ultimum, especially when planted into cold soil. Bio-priming, a seed treatment which combines the establishment of a bioprotectant on the seed with preplant seed hydration, was developed to protect seeds from damping-off.In a series of field experiments conducted in Montana's Bitterroot and Gallatin Valleys, bio-priming or seed bacterization with Pseudomonas fluorescens AB254 protected sweet corn from P. ultimum damping-off. Bio-priming corn seed with P. fluorescens AB254 was comparable to treatment with the fungicide metalaxyl in increasing seedling emergence. Seedlings from bio-primed seeds emerged from the soil more rapidly than from nontreated seeds and were larger at three weeks postplanting. Seeds of sh 2 and sugary enhancer (se) sweet corn, as well as that of several sh 2 cultivars, were protected from damping-off by bio-priming.

scholarly journals Fungicide Seed Treatment Effects on Seedling Damping-off of Pumpkin Caused by Phytophthora capsici

Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M. Babadoost ◽  
S. Z. Islam
Keyword(s):  
Seed Germination ◽  
Untreated Control ◽  
Mycelial Growth ◽  
Seed Treatment ◽  
Culture Medium ◽  
Phytophthora Capsici ◽  
Field Trials ◽  
Seedling Vigor ◽  
Damping Off

Apron XL LS (mefenoxam) and Allegiance FL (metalaxyl) were highly inhibitory to growth of mycelium of Phytophthora capsici in vitro. Effective dose (ED50) of mefenoxam and metalaxyl for 50% inhibition of mycelial growth, for all five isolates of P. capsici tested, was 0.98 and 0.99 μg a.i./ml of culture medium, respectively. For mefenoxam at 200 μg a.i./ml, sporangium and zoospore germination were reduced by 92 and 96%, respectively, and 21 and 24%, respectively, for metalaxyl. In greenhouse studies, seed treatment with mefenoxam (0.42 ml of Apron XL LS/kg of seed) and metalaxyl (0.98 ml of Allegiance FL/kg of seed) significantly reduced pre- and post-emergence damping-off of seedlings caused by P. capsici in three pumpkin cultivars (Dickinson, Hybrid-401, and Hybrid-698) tested. Thirty-one days after seeding, at inoculum levels of 0, 90, 600, 1,400, and 4,000 CFU/g of soil, the average seedling stands for mefenoxam treatment were 98.4, 93.8, 88.3, 77.8, and 64.8%; for metalaxyl, 99.1, 85.3, 85.8, 73.5, and 59.3; and for the untreated control, 97.5, 55.2, 45.7, 37.0, and 22.9%, respectively. In field trials, the average seedling stands 35 days after seeding were 76.7, 74.7, and 44.9% for mefenoxam, metalaxyl, and untreated control, respectively. Seed treatment with mefenoxam or metalaxyl did not have any significant effect on either seed germination or seedling vigor.

scholarly journals Susceptibility of Selected Cotton Cultivars to Seedling Disease Pathogens and Benefits of Chemical Seed Treatments

Plant Disease ◽  
1997 ◽  
Vol 81 (9) ◽  
pp. 1085-1088 ◽  
Author(s):  
Heping Wang ◽  
R. Michael Davis
Keyword(s):  
Seed Treatment ◽  
Seedling Survival ◽  
Pythium Ultimum ◽  
Field Trials ◽  
Thielaviopsis Basicola ◽  
Symptom Development ◽  
Damping Off ◽  
Seedling Disease ◽  
Low Incidence ◽  
Greenhouse Tests

The susceptibility of 12 Upland cotton cultivars to three soilborne fungi, Pythium ultimum, Rhizoctonia solani, and Thielaviopsis basicola, was evaluated in greenhouse experiments. Based on symptom development and seedling survival, cultivars highly resistant to P. ultimum included Delta Pine (DP) 6166, Prema, DP 6100, and Maxxa. A relatively low incidence of pre-emergence damping-off caused by R. solani occurred in ChemBred 7, DP 6100, and Royale, although all cultivars subsequently suffered significant post-emergence damping-off. All cultivars were equally susceptible to T. basicola. In both greenhouse and field evaluations, there were no benefits of metalaxyl seed treatment in Pythium-resistant cultivars. Seed treatment with carboxin-pentachloronitrobenzene for the control of Rhizoctonia-induced damping-off resulted in stand increases in all 12 cultivars in greenhouse tests and in 3 of 6 cultivars in field trials.

Efficacy of Clonostachys rosea strain ACM941 and fungicide seed treatments for controlling the root rot complex of field pea

2003 ◽  
Vol 83 (3) ◽  
pp. 519-524 ◽  
Author(s):  
A. G. Xue
Keyword(s):  
Root Rot ◽  
Untreated Control ◽  
Seedling Emergence ◽  
Field Trials ◽  
Field Pea ◽  
Seed Treatments ◽  
Clonostachys Rosea ◽  
Pea Root ◽  
Pea Root Rot ◽  
Better Than

The efficacy of seed treatments with bioagent ACM941 (a strain of Clonostachys rosea), its formulated products GB116 and ACM941-Pro, and common fungicides for the control of pea root rot complex were examined in six field trials in western Canada from 1996 to 2000. The effects on seedling emergence, root rot severity, and yield varied among years. In trials 1 and 2 (1996–1997), none of the treatments significantly reduced root rot severity or increased yield. ACM941 + Thiram 75WP was the most effective treatment, increasing emergence by 17.4% and was significantly better than that of the untreated controls. In trials 3 and 4 (1997–1998), Apron FL alone and ACM941 + Apron FL were significantly better than the untreated control, increasing emergence by 6.2 and 7.7%, and yield by 10.8 and 11.5%, respectively. In trials 5 and 6 (1999–2000), AC M 941 and GB116 were equally the most effective treatments, increasing emergence by 11.5 and 12.2%, and yield by 8.2 and 6.3%, respectively. These effects were significantly greater than that of the untreated control, but not significantly different from those of Apron FL or Vitaflo-280. ACM941-Pro was developed and tested in 2000 only, and it increased emergence by 17.1% and reduced root rot severity by 29.6%. Key words: Bioagent, Clonostachys rosea, field pea, Pisum sativum, pea root rot complex (PRRC), seed treatment, fungicide

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 Regression Analyses for Evaluating the Influence of Bacillus cereus on Alfalfa Yield Under Variable Disease Intensity

2000 ◽  
Vol 90 (6) ◽  
pp. 657-665 ◽  
Author(s):  
Elizabeth R. Kazmar ◽  
Robert M. Goodman ◽  
Craig R. Grau ◽  
David W. Johnson ◽  
Erik V. Nordheim ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Untreated Control ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Field Trials ◽  
Forage Yield ◽  
Regression Methods ◽  
Control Response ◽  
Treated Seed ◽  
Yield Gain

We developed and tested regression methods to exploit the variability in disease inherent in field experiments, and applied the methods to evaluate strains of Bacillus cereus for biocontrol efficacy. Four B. cereus strains were tested for their effect on alfalfa (Medicago sativa) performance in 16 field trials planted during 1993 to 1996 at multiple sites in Wisconsin. To evaluate performance of the strains, we used the ratio of (metalaxyl response)/(untreated control response) as a measure of disease intensity within the experiments. The ratio of (Bacillus response)/(untreated control response) was then regressed as a function of disease intensity. The slope of the resulting line provides a statistical test to compare performance of the Bacillus strain with that of the untreated seed (Ho: slope = 0) and metalaxyl controls (Ho: slope = 1). Under conditions in which disease occurred, forage yield of plots planted with seed treated with B. cereus strain AS4–12 exceeded yield from the untreated control plots (P = 0.002) and was similar to yield of plots planted with metalaxyl-treated seed (P = 0.14). Yield gain associated with AS4–12 and metalaxyl seed treatment averaged 6.1 ± 2.8% (±standard error) and 3.0 ± 2.8%, respectively. In contrast to the regression approach, means analysis by analysis of variance did not detect differences among treatments. Three other B. cereus strains either did not increase alfalfa yield or increased yield less than did AS4–12. Metalaxyl and three of the Bacillus strains increased seedling emergence, but the improved stands were not predictive of increased forage yield. In six additional studies conducted for one season in 1997, AS4–12 enhanced yield of two cultivars at diverse locations in Wisconsin, but there was an apparent cultivar-location interaction. A strong correlation between response to AS4–12 and metalaxyl treatment suggests that these treatments controlled similar pathogens, most likely the oomycete pathogens Phytophthora medicaginis and Pythium spp.

Effect of seeding date and depth, seed size and fungicide treatment on Fusarium and Pythium seedling blight of canola

2015 ◽  
Vol 95 (2) ◽  
pp. 293-301 ◽  
Author(s):  
S. F. Hwang ◽  
H. U. Ahmed ◽  
G. D. Turnbull ◽  
B. D. Gossen ◽  
S. E. Strelkov
Keyword(s):  
Seed Size ◽  
Seed Yield ◽  
Seed Treatment ◽  
Seedling Emergence ◽  
Pythium Ultimum ◽  
Seedling Blight ◽  
Substantial Impact ◽  
Fungicide Treatment ◽  
Stand Establishment ◽  
Seeding Date

Hwang, S. F., Ahmed, H. U., Turnbull, G. D., Gossen, B. D. and Strelkov, S. E. 2015. Effect of seeding date and depth, seed size and fungicide treatment on Fusarium and Pythium seedling blight of canola. Can. J. Plant Sci. 95: 293–301. Seedling blight has a substantial impact on stand establishment and productivity of canola (Brassica napus) on the Canadian prairies. The effects of seeding date, seed size, seeding depth, and seed treatment fungicides on seedling blight of canola caused by Fusarium avenaceum and Pythium ultimum were evaluated under field conditions. In the trials inoculated with P. ultimum, early seeding reduced seedling emergence and seed yield in all 3 yr of the study. However, the interaction of F. avenaceum with seeding date was not consistent; inoculation with F. avenaceum reduced seedling emergence in early seeded canola in 1 of 4 yr, but emergence was higher in early than in mid-seeded treatments in 2 yr and there was no difference among seeding dates in 1 yr. Late seeding reduced seed yield in 2 of 4 yr in the F. avenaceum study. Seed size and seeding depth generally did not have an effect on seedling establishment or seed yield for either pathogen. Seed treatment with Helix Xtra (thiamethoxam+difenconazole+metalaxyl+fludioxonil) and Prosper FX (clothianidin+carboxin+trifloxystrobin+metalaxyl) fungicides increased seedling emergence and yield compared with the F. avenaceum-inoculated control. Seed treatment with Helix Xtra also increased seedling emergence and seed yield compared with the P. ultimum-inoculated control. Manipulation of seeding date did not substantially improve stand establishment or yield of canola when inoculum pressure was high. Seed treatment was the most effective strategy for reducing losses caused by seedling blight of canola in fields infested with F. avenaceum or P. ultimum.

Effect of seed treatments on emergence, yield, and root rot severity of soybean under Rhizoctonia solani inoculated field conditions in Ontario

2007 ◽  
Vol 87 (1) ◽  
pp. 167-174 ◽  
Author(s):  
A. G. Xue ◽  
E. Cober ◽  
M. J. Morrison ◽  
H. D. Voldeng ◽  
B. L. Ma
Keyword(s):  
Rhizoctonia Solani ◽  
Root Rot ◽  
Seed Treatment ◽  
Bacillus Pumilus ◽  
Field Trials ◽  
Natural Soil ◽  
Seed Treatments ◽  
Untreated Seed ◽  
Plant Emergence ◽  
Better Than

Field trials were conducted with soybean at two sites each year from 2001 to 2003 in Ottawa, ON, to determine the effect of seed treatments with various combinations of seven formulated fungicides and the bioagent Yield Shield (Bacillus pumilus GB34) under Rhizoctonia solani inoculated conditions. Controls were untreated seed planted into both non-inoculated (natural) soil and soil inoculated with R. solani. Compared with the non-inoculated control, inoculation significantly increased root rot severity and reduced emergence by 27%, and yield by 31%. Under the inoculated conditions, none of the seed treatments significantly increased emergence or yield in all of the six trials when compared with the control. Allegiance (metalaxyl) plus Vitaflo-280 (carbathiin plus thiram) and Vitaflo-280 alone were the most effective seed treatments, increasing emergence in by 20 and 19% and yield by 21 and 26%, which were significantly better than the control in four and five trials for emergence and three and four trials for yield, respectively. Allegiance plus HEC5725 (HEC5725), Apron Maxx RTA (fludioxonil plus metalaxyl), and Maxim 480FS (fludioxonil) increased both emergence and yield in two trials and TFL RTU (metalaxyl plus triflox ystrobin) plus Yield Shield in one trial. There was no difference between seed treatment with Allegiance and the untreated control for all parameters, confirming that metalaxyl is ineffective to R. solani. It is concluded that carbathiin, thiram, HEC5725, fludioxonil an trifloxystrobin are effective active ingredients protecting soybean from soil-borne R. solani and increasing plant emergence and yield. Key words: Rhizoctonia solani, seed treatment, soybean, Glycine max, fungicide, bioagent

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