scholarly journals Control of Cotton Seedling Damping-off in the Field by Burkholderia (Pseudomonas) cepacia

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 291-293 ◽  
Author(s):  
K. Zaki ◽  
I. J. Misaghi ◽  
A. Heydari ◽  
M. N. Shatla
Keyword(s):  
Bacillus Subtilis ◽  
Seed Treatment ◽  
Field Trials ◽  
The Other ◽  
Peat Moss ◽  
Pseudomonas Cepacia ◽  
Damping Off ◽  
Cotton Seedling ◽  
Soil Drench

Four field trials were conducted in April 1995 and 1996 in Arizona to compare the effectiveness of: 1, a soil drench of isolate D1 of Burkholderia (Pseudomonas) cepacia; 2, isolate D1 barley meal formulation; 3, Deny seed treatment (a peat moss-based formulation of B. cepacia); 4, Deny soil drench; 5, Kodiak seed treatment (a formulation of Bacillus subtilis); 6, a mixture of three fungicides (metalaxyl, triadimenol, and thiram) seed treatment; and 7, a mixture of metalaxyl, triadimenol, thiram, and Kodiak seed treatment to increase cotton stand in the field. Except for D1, the other products are being marketed for the control of cotton seedling damping-off. Only D1 soil drench and a mixture of the three fungicides seed treatment increased cotton stand significantly (P ≤ 0.05) in three of four field trials.

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 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 Benefits of Cotton Seed Treatments for the Control of Seedling Diseases in Relation to Inoculum Densities of Pythium Species and Rhizoctonia solani

Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 766-768 ◽  
Author(s):  
R. M. Davis ◽  
J. J. Nunez ◽  
K. V. Subbarao
Keyword(s):  
Rhizoctonia Solani ◽  
Cotton Seed ◽  
Seed Treatment ◽  
Field Trials ◽  
Particle Analysis ◽  
Soil Parameters ◽  
Pythium Species ◽  
Damping Off ◽  
Air Temperatures ◽  
Pathogen Populations

Twenty-five field trials conducted over a 3-year period in five San Joaquin Valley counties included the following treatments: nontreated cotton seed; seed treated with myclobutanil for the control of Rhizoctonia solani-induced damping-off; seed treated with metalaxyl for the control of Pythium-induced damping-off; and seed treated with a combination of the two fungicides. The following parameters were measured: soil populations of Pythium spp. and R. solani at planting, soil temperature at planting, air temperatures for 5 days after planting, soil particle analysis, EC, calcium, pH, organic matter, and plant stands from each treatment. In 1993 and 1994, myclobutanil and the combination of the two fungicides resulted in improved stands in 15 of 18 fields. Metalaxyl did not increase stands in any field in 1993 to 1994. In 1995, the combination of fungicides increased stands relative to the nontreated seeds and was more effective in increasing stands than myclobutanil or metalaxyl alone. Pythium populations were much greater in 1995 than in 1993 to 1994 and may explain the increase in plant stands with the combination of fungicides and metalaxyl alone. Covariate analysis of the data indicated no relationship between stand increases from fungicide seed treatment and any of the soil parameters measured. Heat units following planting were not limiting and had no effect on stands. Populations of pathogens were not related to benefits of fungicides, with the exception of a negative correlation between stand increases from seed treatment with myclobutanil and Pythium populations. Apparently, seed protected with a fungicide active against R. solani were more susceptible to infection by Pythium spp. In general, the fungicide seed treatment active against R. solani increased stands of the cultivar Maxxa regardless of soil type and pathogen populations. Increased stands from the metalaxyl treatment occurred in 1 of the 3 years of the study.

scholarly journals Fengycin produced by Bacillus subtilis NCD-2 plays a major role in biocontrol of cotton seedling damping-off disease

2014 ◽  
Vol 169 (7-8) ◽  
pp. 533-540 ◽  
Author(s):  
Qinggang Guo ◽  
Weixin Dong ◽  
Shezeng Li ◽  
Xiuyun Lu ◽  
Peipei Wang ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Damping Off ◽  
Cotton Seedling

scholarly journals Cotton Seedling Preemergence Damping-Off Incited by Rhizopus oryzae and Pythium spp. and Its Biological Control with Trichoderma spp.

2002 ◽  
Vol 92 (2) ◽  
pp. 177-180 ◽  
Author(s):  
C. R. Howell
Keyword(s):  
Biological Control ◽  
Wheat Bran ◽  
Seed Treatment ◽  
Rhizopus Oryzae ◽  
Infested Soil ◽  
Damping Off ◽  
Trichoderma Spp ◽  
Cotton Seedling ◽  
Germination Stimulants ◽  
Infested Field

Planting the cotton cv. Sure-Grow 747 in cotton seedling disease plots during the 2001 growing season resulted in high levels of preemergence damping-off among the seedlings. Four cotton pathogens, Pythium aphanidermatum, P. ultimum, an unidentified Pythium sp., and Rhizopus oryzae, were isolated from diseased seed embryos and seedlings. Disease incited by the Pythium spp. could be controlled by seed treatment with Metalaxyl, but disease incited by R. oryzae could not. Seed treatment with Metalaxyl in naturally infested field soil was only partially effective; therefore, symptoms in 47% of the diseased seedlings could be attributed to R. oryzae. Susceptibility to disease appeared to be related to release in the spermosphere, by the germinating seeds, of compounds that stimulate pathogen propagule germination, because exudates from seed of the suscept Sure-Grow 747 and extracts from wheat bran induced pathogen germination and growth, whereas exudates from resistant cv. Stoneville 213 did not. However, even Stoneville 213 became susceptible when infested soil was amended with wheat bran. Seed treatment with preparations of Trichoderma virens parent, mutant, and hybrid strains gave effective biological control of preemergence damping-off. Disease control was attributable to metabolism by the biocontrol agent of pathogen germination stimulants released by the seed, because amendment of pathogen-infested soil with the propagule germination stimulants in wheat bran negated the protective effect of the seed treatment.

scholarly journals Use of Lentinan and Fluopimomide to Control Cotton Seedling Damping-Off Disease Caused by Rhizoctonia solani

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 75
Author(s):  
Shoumin Sun ◽  
Haohao Yan ◽  
Gang Chen ◽  
Shuai Yang ◽  
Jie Wang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Rhizoctonia Solani ◽  
Plant Disease Resistance ◽  
Field Trials ◽  
Cotton Production ◽  
Damping Off ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Cotton Seeds ◽  
Acid Pathway

Lentinan (LNT) is a natural and functional polysaccharide isolated from Lentinus edodes fruiting bodies, which functions in stimulating the plant immune response, improving plant disease resistance and regulating plant growth. This study explores the use of LNT as a plant growth regulator and attractant in cotton production. After treatment with LNT, the content of malondialdehyde (MDA) in cotton seeds decreased, whereas the activities of polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) in leaves increased significantly. LNT also promoted the growth and development of cotton plants and significantly reduced the incidence of cotton damping-off disease. The relative expression of salicylic acid pathway-related genes in cotton also increased significantly. The prevention mechanism of fluopimomide was also evaluated, and the result showed lower EC50 values and was effective in controlling cotton seedling disease caused by Rhizoctonia solani in both greenhouse experiments and field trials. The use of LNT and fluopimomide in controlling cotton seedling damping-off disease showed a synergistic effect in field trials. These results will provide a new insight into the agricultural application of LNT as a biological fungicide in the field of biological controls.

scholarly journals The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

2010 ◽  
Vol 2 (2) ◽  
pp. 46-55
Author(s):  
Montaser Fawzy ABDEL-MONAIM ◽  
Mamdoh Ewis ISMAIL
Keyword(s):  
Root Rot ◽  
Total Yield ◽  
Dry Weight ◽  
The Other ◽  
Antioxidant Compounds ◽  
Damping Off ◽  
Soil Drench ◽  
Progress Curve ◽  
Pepper Plants ◽  
Plant Length

Ten isolates of Fusarium spp. were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. 'Anaheim-M'). The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm) were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

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.

scholarly journals Biocontrol of Stemphylium vesicarium and Pleospora allii on Pear by Bacillus subtilis and Trichoderma spp.: Preventative and Curative Effects on Inoculum Production

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1455
Author(s):  
Concepció Moragrega ◽  
Alba Carmona ◽  
Isidre Llorente
Keyword(s):  
Bacillus Subtilis ◽  
Field Trials ◽  
Trichoderma Spp ◽  
Vegetative Period ◽  
Stemphylium Vesicarium ◽  
Inoculum Production ◽  
Preventative Strategy ◽  
Pleospora Allii ◽  
Pathogen Colonization ◽  
Different Strains

Trials under controlled and field conditions were conducted to establish the effect of strategies of application of biological control agents (BCAs) in the reduction of Stemphylium vesicarium and Pleospora allii inoculum production on pear leaf debris. Six BCAs based on different strains of Trichoderma spp. (Tr1, Tr2) and Bacillus subtilis (Bs1, Bs2, Bs3 and Bs4) were evaluated. Two strategies were tested in controlled experiments: application before (preventative strategy) or after (curative strategy) pear leaf debris colonization by S. vesicarium, evaluating the growth inhibition and sporulation of S. vesicarium and the pseudothecia production of P. allii. When the BCAs were applied preventatively, the efficacy of treatments based on B. subtilis was higher than those based on Trichoderma spp. in controlling the pathogen colonization, but that of controlling the inoculum production of S. vesicarium and P. allii was similar. However, when the BCAs were applied curatively, Trichoderma based products were more effective. In field trials, Trichoderma spp. Tr1 and B. subtlilis Bs1 produced a consistent 45–50% decrease in the number of S. vesicarium conidia trapped compared to the non-treated control. We conclude that Bacillus subtilis Bs1 and Trichoderma spp. Tr1 and Tr2 can be expected to reduce fungal inoculum during the pear vegetative period by at least 45–50%. Additionally, Trichoderma spp. Tr1 and Tr2 have the potential to reduce the fungal overwintering inoculum by 80% to 90%.

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