scholarly journals APPLICATION OF SALICYLIC ACID AND SOME FUNGICIDES AS SEED TREATMENT FOR CONTROLLING DAMPING-OFF AND ROOT ROT DISEASES OF SQUASH AND CANTALOUPE PLANTS UNDER FIELD CONDITIONS.

2014 ◽  
Vol 5 (12) ◽  
pp. 1025-1043 ◽  
Author(s):  
Gehad Mohamed ◽  
Saida Amer
Keyword(s):  
Salicylic Acid ◽  
Root Rot ◽  
Seed Treatment ◽  
Field Conditions ◽  
Damping Off

scholarly journals The Role of Salicylic Acid and Pseudomonas fluorescens in Systemic Resistance Against Rhizoctonia solani kühn in Guar (Cyamopsis tetragonoloba (l.) Taub.)

2017 ◽  
Vol 6 (1) ◽  
pp. 01-15
Author(s):  
Montaser F. Abdel-Monaim
Keyword(s):  
Salicylic Acid ◽  
Rhizoctonia Solani ◽  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Yield Components ◽  
Growth Parameters ◽  
Field Conditions ◽  
Systemic Resistance ◽  
Cyamopsis Tetragonoloba ◽  
Damping Off

Rhizoctonia solani was found to be associated with root rot symptoms of guar plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack guar plants (cv. Local) causing damping-off and root rot diseases. R. solani isolates No. 8 (RG8) was the more virulent ones in the pathogenicity tests. Salicylic acid (SA) and Pseudomonas fluorescens (PF) individually or in combination were examined for their potential in suppression damping-off and root rot and growth promotion of guar plants in vitro and in vivo. Both SA and P. fluorescens either individually or in combination inhibited the growth of the tested pathogenic fungi.SA combined with P. fluorescens recorded the highest inhibited growth followed by P. fluorescens alone. Under greenhouse and field conditions, all treatments significantly reduced damping-off and root rot severity. The combination of SA and P. fluorescens was more effective than using them individually.  Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1) and yield components (No. of pods plant-1, weight of 100 seeds and total yield fed.-1 and Guaran content (gm plant-1) in both locations (El-Kharga and Mallawy Agric. Res. Stations) during growing season 2014.The combination of SA and P. fluorescens were recorded the highest growth parameters and yield components. Generally, the combination of SA and P. fluorescens recorded the best results for controlling damping-off and root rot diseases in greenhouse and field with addition improved plant growth and increased yield components in the field. In physiological studies, activity of defense-related enzymes, including peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), pathogenesis related (PR) protein (chitinase and β 1,3 gluconase), were increased in inoculated and non-inoculated plants treated with the SA and P. fluorescens either individually or in combination, during the experimental period. The combination of SA and P. fluorescens recorded the highest increase in activity of all enzymes.  In general, the activity of these enzymes begins to accumulate after two days of treatment and reached maximum levels at 6 to 10 days, then the activities of these enzymes were decreased progressively. On the other hand, total phenols and lignin increased in guar plants inoculated with R. solani and treated with SA and P. fluorescens individually or in combination. The highest accumulation of phenols was recorded 8th days from application, while lignin recorded the highest level at 10th days from application. In the end, these results suggested that SA and P. fluorescens either individually or in combination may play an important role in controlling the guar damping-off and root rot diseases, though they have induction of systemic resistance in guar plants.

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.

scholarly journals Improvment Biocontrol of Damping-Off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide

2013 ◽  
Vol 2 (1) ◽  
pp. 14-24
Author(s):  
Montaser F. Abdel-Monaim
Keyword(s):  
Hydrogen Peroxide ◽  
Salicylic Acid ◽  
Faba Bean ◽  
Root Rot ◽  
Yield Components ◽  
Growth Parameters ◽  
Biocontrol Agents ◽  
Damping Off ◽  
Chemical Inducers ◽  
Bean Plants

Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride, Bacillus megaterium) and chemical inducers (salicylic acid and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promotion of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi.Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA+ B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/ wilt severity and increased survival of plants. Also, these treatments increased fresh and dry weights of the survived plants in pots compared with control.  The combination of biocontrol agents and chemical inducers were more effective than using them individually and SA+ T. viride was the best treatment in this respect. Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1) and yield components (No. of pods and seedsplant-1, weight of 100 seeds and total yield feddan-1 and protein content in both seasons (2010-2011 and 2011-2012). Faba bean seeds soaked in SA+ T. viride and SA+ B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination of biocontrol agents and chemical inducers recoded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in the field. 

scholarly journals Root parsley protection against damping off

2013 ◽  
Vol 55 (1) ◽  
pp. 255-263 ◽  
Author(s):  
Bogdan Nowicki
Keyword(s):  
Disease Control ◽  
Seed Treatment ◽  
Field Conditions ◽  
Lower Percentage ◽  
Damping Off ◽  
Phytotoxic Effects ◽  
Fungicide Mixtures

Seed treatment ofroot parsley was done to protect <i>Petroselinum santivum</i> seedlings against damping off. Fungicides used as seed dressers were applied in 3 doses: 3, 5 and 10 g/kg. Seeds were treated with 7 dressers (Table l) used separately and in mixture with 3 g/kg of Rovral 50 WP (50% iprodione) and 1 g/kg of Apron 35 SD (35% metalaxyl). Two seed samples of Berlińska cultivar were used: first sample was strongly infected by <i>Alternaria petroselini</i> and <i>A.radicina</i> both 27,6% and also by <i>Fusarium</i> spp. 5,4% (Test I), and second sample revealed lower percentage of infection 4,6% and 1,2%, respectively (Test II). The experiments were conducted under laboratory, glasshouse and field conditions. Complete seedlings protection in all experiments was achieved for treatments when fungicide mixture was used in the highest dose (10 g/kg). Decrease of fungicides concentrations were connected with lower effectiveness of disease control. No phytotoxic effects of the tested fungicide mixtures were observed under the glasshouse or field conditions.

scholarly journals Seed Treatment Using Pre-infiltration and Biocontrol Agents to Reduce Damping-off of Corn Caused by Species of Pythium and Fusarium

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 294-299 ◽  
Author(s):  
W. Mao ◽  
R. D. Lumsden ◽  
J. A. Lewis ◽  
P. K. Hebbar
Keyword(s):  
Disease Control ◽  
Plant Height ◽  
Root Rot ◽  
Seed Treatment ◽  
Pythium Ultimum ◽  
Biocontrol Agents ◽  
Infested Soil ◽  
Damping Off ◽  
Fresh Weight ◽  
Inoculum Rate

Bioassays were conducted in a greenhouse at 18°C to determine the effectiveness of a seed treatment used in combination with biocontrol agents for the reduction of corn damping-off caused by species of Pythium and Fusarium. Corn seeds were infiltrated with tap water, drained, air-dried, and then coated with biomass of an antagonistic fungus, Gliocladium virens isolate Gl-3, or an antagonistic bacterium, Burkholderia cepacia isolates Bc-B or Bc-1, or a combination of Gl-3 with each of the bacterial isolates. A nonsterile field soil was infested with a combination of pathogens: Pythium ultimum, P. arrhenomanes, and Fusarium graminearum at 2 inoculum rates (1× and 4×). Pre-infiltration enhanced (P ≤ 0.05) disease control with most treatments at both inoculum rates. Treatments with biocontrol agents alone or in combination, as well as the fungicide captan, effectively reduced the disease at a pathogen inoculum rate of 1×, resulting in greater (P ≤ 0.05) seedling stands, plant height, and fresh weight, and lower (P ≤ 0.05) root rot severity compared with untreated seeds in infested soil. At a pathogen inoculum rate of 4×, stands were lower (P ≤ 0.01) and root-rot severity was higher (P ≤ 0.01) compared to those at 1× for all treatments. Nevertheless, coating seeds with all biocontrol agents (alone or in combination), except with Bc-1 alone, reduced disease (P ≤ 0.05) compared to untreated seeds in infested soil. At both inoculum rates of 1× and 4×, coating seeds with Gl-3 + Bc-B was more effective (P ≤ 0.05) in disease control than any other treatment, resulting in stands, growth rate (plant height and fresh weight), and root rot severity similar to plants from untreated seeds in noninfested soil. In addition, when the exudate from a 2-h infiltration of corn seed was added to the seeds during seed coating, seedling stand was often lower and root rot severity was often higher than those from infiltrated seeds (P ≤ 0.05). These results indicated that the infiltration process removed certain exudates, including nutrients and/or stimulants (not detected in this study) that might be utilized by pathogens to initiate seed infection. A thin-layer chromatography (TLC) profile of the exudates showed the presence of eight amino acids and three major carbohydrates.

scholarly journals Combination of biological control agents and garlic (allium sativum) extract in reducing damping-off disease of tomato

2019 ◽  
Vol 44 (3) ◽  
pp. 553-567 ◽  
Author(s):  
VO Dania ◽  
JA Omidiora
Keyword(s):  
Biological Control ◽  
Seed Treatment ◽  
Field Experiments ◽  
Block Design ◽  
Tomato Fruit ◽  
Fruit Yield ◽  
Field Conditions ◽  
Biological Control Agents ◽  
Damping Off ◽  
Seedling Mortality

Damping-off (Pythium aphanidermatum) is a soil-borne disease which accounts for seedling mortality and significant yield losses in tomato production. Laboratory and screenhouse experiments were conducted in 2017, with a repeated field trial in 2018 to evaluate the efficacy of combining three biological control agents (BCAs), Trichodermaviride, T. harzianumand Bacillus subtilis with Allium sativumextract for the integrated management of the disease in tomato crop. Treatments were laid out in a completely randomized design and randomized complete block design in the screenhouse and field experiments, respectively with eighteen treatments and three replications. The BCAs and extract were formulated and applied using seed treatment and soil sprinkling methods. Treatment combinations of BCAs with A. sativumwere more effective in the reduction of mycelial growth of the pathogen with inhibitory values that ranged between 77.6-91.2% than single inoculation. Seed treatment before planting was more effective than soil sprinkle method, reducing pre-emergence and damping-off incidence to between 6.8-18.3% and 9.7-26.3% under screenhouse and field conditions, respectively than the sprinkling method. Soil sprinkle with T. harzianumin combination with A. sativumextract had the highest cumulative tomato fruit yield of 902 kg/ha-1under field conditions. This study showed that combined application of BCAs and A. sativumextract reduced damping-off disease and thereby improved the fruit yield of tomato. Bangladesh J. Agril. Res. 44(3): 553-567, September 2019

scholarly journals Seed Rot and Damping-off of Alfalfa in Minnesota Caused by Pythium and Fusarium Species

Plant Disease ◽  
2017 ◽  
Vol 101 (11) ◽  
pp. 1860-1867 ◽  
Author(s):  
Laurine E. Berg ◽  
Susan S. Miller ◽  
Melinda R. Dornbusch ◽  
Deborah A. Samac
Keyword(s):  
Root Rot ◽  
Seed Treatment ◽  
Production Systems ◽  
Fusarium Species ◽  
Broad Host Range ◽  
Damping Off ◽  
Pythium Sylvaticum ◽  
Seed Rot ◽  
New Strategies

Globally, 15 Pythium species have been found to cause damping-off and seed rot of alfalfa, although surveys of species causing disease on alfalfa in the midwestern United States are lacking. Pathogens were isolated by a seedling baiting technique from soil samples of five alfalfa fields in Minnesota with high levels of damping-off. Of the 149 organisms isolated, 93 (62%) were identified as Pythium spp. and 43 (29%) were identified as Fusarium species. Pythium sylvaticum, P. irregulare, and P. ultimum var. ultimum were aggressive pathogens on germinating alfalfa seedlings. Strains of seven Pythium spp. pathogenic on soybean and corn were also pathogenic on alfalfa. The majority of the Fusarium isolates were identified as F. solani and F. oxysporum with a low number of F. redolens and F. incarnatum-equiseti. The F. oxysporum and F. incarnatum-equiseti strains were the most aggressive in causing seed and root rot. Pythium strains were sensitive to Apron XL (mefenoxam) and pyraclostrobin in vitro but efficacy varied when the fungicides were applied as a seed treatment. Seed treatments with Apron XL were more effective than treatments with Stamina against Pythium. The presence of aggressive, broad-host-range pathogens causing seed rot and damping-off suggests that new strategies are needed for managing this disease in alfalfa production systems.

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