Combining Trichoderma hamatum THSW13 and Pseudomonas aeruginosa BJ10–86: a synergistic chili pepper seed treatment for Phytophthora capsici infested soil

Pythium ultimum var. sporangiiferum (76 isolates) and P. aphanidermatum (21 isolates) cultured from diseased sugar beet seedlings in Minnesota and North Dakota were tested for sensitivity to metalaxyl, pathogenicity on sugar beet, and disease control by metalaxyl seed treatment. Sensitivity to metalaxyl (effective concentration causing 50% growth inhibition [EC50]) was determined by linear growth on corn meal agar amended with 0, 0.01, 0.1, 1, 10, and 100 μg a.i. metalaxyl ml-1 after 48 h in the dark at 21 ± 1°C. Variation among isolates was significant (P = 0.05) within and between species, and EC50 values averaged 0.16 (range: 0.05 to 1.30 μg ml-1) for P. ultimum var. sporangiiferum and 2.06 (range: 1.19 to 3.12 μg ml-1) for P. aphanidermatum. In pathogenicity tests on sugar beet, most isolates of P. ultimum var. sporangiiferum (72 of 76) and all of P. aphanidermatum significantly (P = 0.05) decreased final stands compared to the noninoculated control. There was no correlation between aggressiveness in the absence of metalaxyl and in vitro sensitivity to metalaxyl. When Pythium-infested soil was planted with seed treated with metalaxyl at the standard (0.625 g a.i. kg-1) or half rate, some isolates that were least sensitive to metalaxyl in vitro resulted in a significant (P = 0.05) reduction in disease control. These results may explain, at least in part, why producers do not attain expected stands when they plant metalaxyl-treated sugar beet seed.

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Isolation and in vitro and in vivo activity against Phytophthora capsici and Colletotrichum orbiculare of phenazine-1-carboxylic acid from Pseudomonas aeruginosa strain GC-B26

Pest Management Science ◽

10.1002/ps.688 ◽

2003 ◽

Vol 59 (8) ◽

pp. 872-882 ◽

Cited By ~ 39

Author(s):

Jung Yeop Lee ◽

Surk Sik Moon ◽

Byung Kook Hwang

Keyword(s):

Pseudomonas Aeruginosa ◽

Carboxylic Acid ◽

Phytophthora Capsici ◽

Colletotrichum Orbiculare

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Evaluation of Winter Squash and Pumpkin Cultivars for Age-related Resistance to Phytophthora capsici Fruit Rot

HortScience ◽

10.21273/hortsci11173-16 ◽

2016 ◽

Vol 51 (10) ◽

pp. 1251-1255 ◽

Cited By ~ 4

Author(s):

Charles S. Krasnow ◽

Mary K. Hausbeck

Keyword(s):

Cucurbita Pepo ◽

Disease Incidence ◽

Phytophthora Capsici ◽

Genetic Resistance ◽

Fruit Rot ◽

Infested Soil ◽

Cucurbita Moschata ◽

Cucurbita Maxima ◽

Age Related ◽

Winter Squash

Phytophthora capsici annually threatens production of cucurbit and solanaceous crops. Long-lived oospores produced by the pathogen incite primary infection of susceptible plants when conditions are wet. Limiting the rot of winter squash and pumpkin (Cucurbita sp.) fruits is difficult due to the long maturation period when fruits are often in direct contact with infested soil. Genetic resistance to fruit rot is not widely available within Cucurbita sp.; however, age-related resistance (ARR) to P. capsici fruit rot develops in specific cultivars during maturation. The objective of this study was to evaluate the fruits of 12 cultivars of Cucurbita pepo, Cucurbita moschata, and Cucurbita maxima for ARR to P. capsici using a mycelial-plug inoculation method. All Cucurbita pepo and Cucurbita moschata cultivars displayed ARR; 7 days postpollination (dpp) fruits were susceptible, limited lesion development occurred on fruits 22 dpp, and lesions did not develop at 56 dpp. Disease developed on both Cucurbita maxima cultivars tested at 7, 14, 22, and 56 dpp. Firmness of fruit exocarps was measured with a manual penetrometer. Exocarp firmness of all cultivars increased during maturation; however, there was no correlation between firmness and disease incidence among cultivars at 22 dpp (R2 = −0.01, P = 0.85). When fruits of cultivars expressing ARR at 22 dpp were wounded before inoculation, fruit rot developed.

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CONTROL OF ROOT DISEASE IN PEAS BY SEED TREATMENT IN SOUTHERN ALBERTA

Canadian Journal of Plant Science ◽

10.4141/cjps64-105 ◽

1964 ◽

Vol 44 (6) ◽

pp. 531-537 ◽

Cited By ~ 3

Author(s):

F. R. Harper

Keyword(s):

Pisum Sativum ◽

Seed Treatment ◽

Root Disease ◽

Infested Soil ◽

Fusarium Spp ◽

Untreated Seed ◽

Pisum Sativum L ◽

Southern Alberta

The effectiveness of seven different fungicide treatments on peas (Pisum sativum L.) was determined on irrigated land in southern Alberta from 1961 to 1963. Emergence and yield were higher from treated than from untreated seed. Captan, Semesan, and Bayer 47531 were the most effective fungicides.The fungicides did not influence either the type or frequency of isolation of pathogens from roots at harvest. Fusarium spp. and Pythium spp. were the fungi most frequently isolated from diseased roots. Pythium was isolated from seeds germinated for 3 days at 15 °C in moist, naturally infested soil, but no pathogens were isolated from seeds treated with captan. Although emergence from untreated seed of six varieties of peas differed with location and variety, emergence from the seed treated with 65% captan was uniformly high. Captan protected both sound and damaged seed from attack by pathogens.

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Peningkatan Pertumbuhan Tanaman Cabai dan Pengendalian Busuk Phytophthora melalui Biopriming Benih dengan Rizobakteri Asal Pertanaman Cabai Jawa Timur

Jurnal Hortikultura Indonesia ◽

10.29244/jhi.8.3.171-182 ◽

2017 ◽

Vol 8 (3) ◽

pp. 171 ◽

Cited By ~ 2

Author(s):

Aulia Zakia ◽

Satriyas Ilyas ◽

Candra Budiman ◽

Syamsuddin , ◽

Dyah Manohara

Keyword(s):

Plant Growth ◽

Seed Treatment ◽

Block Design ◽

Phytophthora Capsici ◽

Positive Control ◽

Negative Control ◽

Phytophthora Blight ◽

Blight Disease ◽

And Control ◽

East West

ABSTRACT The objectives of this study was to evaluate biopriming of chili seed with rhizobacteria to improve plant growth and control Phytophthora blight disease in a greenhouse. This experiment used three isolates of rhizobacteria, i.e. E1, E3C2 and F2B1, and isolate Phytophthora capsici (Cb6) isolated from the production center of chili in East Jawa. Laris variety from PT. East West was used in this experiment. This experiment used randomized block design with one factor, i.e. 11 levels of seed treatment (E1 rhizobacteria, E3C2 rhizobacteria, F2B1 rhizobacteria, E1+E3C2 rhizobacteria, E1+F2B1 rhizobacteria, E1+E3C2+F2B1 rhizobacteria, seed soaking in water, without soaking, metalaxyl, positive control and negative control). The result showed that seed treatment with combination of E1+F2B1 isolates when grown in nursery, significantly increased the height and number of leaves in chilli. Besides, seed treatment with F2B1 isolate and combination of E1+F2B1 isolates after transplanting were capable to improve plant growth and control Phytophthora blight disease in greenhouse.Keywords: greenhouse, isolate rhizobacteria, Phytophthora capsici ABSTRAK Tujuan penelitian ini ialah mengevaluasi perlakuan biopriming benih cabai dengan rizobakteri dalam meningkatkan pertumbuhan bibit dan mengendalikan kejadian busuk Phytophthora di rumah kaca. Perlakuan biopriming benih dengan rizobakteri menggunakan tiga isolat rizobakteri E1, E3C2 dan F2B1 dan isolat Phytophthora capsici Cb6 hasil eksplorasi pertanaman cabai Jawa Timur. Benih yang digunakan dalam percobaan merupakan benih varietas Laris produksi PT. East West. Percobaan menggunakan rancangan acak kelompok satu faktor, masing-masing perlakuan diulang empat kali, dengan 11 taraf perlakuan, antara lain R0+ (kontrol positif, benih direndam dalam PDB tanpa perlakuan rizobakteri dengan inokulasi P. capsici), R0- (kontrol negatif, benih direndam dalam PDB tanpa perlakuan rizobakteri dan tanpa inokulasi P. capsici), R1 (perlakuan benih dengan isolat E1), R2 (isolat E3C2), R3 (isolat F2B1), R4 (kombinasi isolat E1+E3C2), R5 (kombinasi isolat E1+F2B1), R6 (kombinasi isolat E1+E3C2+F2B1), R0RA (benih direndam dalam air 24 jam), R0TR (benih tanpa rendam), R0M (benih direndam dalam metalaksil). Tanah inokulum P. capsici diberikan 28 hari setelah pindah-tanam di sekitar pangkal batang tanaman cabai di bawah permukaan tanah. Hasil percobaan menunjukkan, perlakuan dengan kombinasi isolat E1+F2B1 saat persemaian di rumah kaca nyata meningkatkan tinggi dan jumlah daun tanaman cabai. Perlakuan benih dengan isolat F2B1 maupun kombinasi isolat E1+F2B1 setelah pindah-tanam di rumah kaca memiliki kemampuan meningkatkan pertumbuhan tanaman serta mengendalikan penyakit busuk Phytophthora. Kata kunci: isolat rizobakteri, Phytophthora capsici, rumah kaca

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

Plant Disease ◽

10.1094/pdis.2003.87.1.63 ◽

2003 ◽

Vol 87 (1) ◽

pp. 63-68 ◽

Cited By ~ 37

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.

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Quantification of Phytophthora capsici Oospores in Soil by Sieving-Centrifugation and Real-Time Polymerase Chain Reaction

Plant Disease ◽

10.1094/pdis-92-1-0143 ◽

2008 ◽

Vol 92 (1) ◽

pp. 143-149 ◽

Cited By ~ 30

Author(s):

C. F. Pavón ◽

M. Babadoost ◽

K. N. Lambert

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

Sucrose Solution ◽

Quantitative Polymerase Chain Reaction ◽

Phytophthora Capsici ◽

Soil Samples ◽

Infested Soil ◽

Chain Reaction ◽

Polymerase Chain ◽

The Relationship

A procedure was developed to quantify Phytophthora capsici oospores in soil by combining a sieving-centrifugation method and a real-time quantitative polymerase chain reaction (QPCR) assay. Five soil samples representing three different soil textures were infested with oospores of P. capsici to produce 101, 102, 103, 104, or 105 spores per 10 g of air-dried soil. Each 10-g sample of infested soil was suspended in 400 ml of water and then passed through 106-, 63-, and 38-μm metal sieves. The filtrate was then passed through a 20-μm mesh filter. Materials caught on the filter were washed with water into two 50-ml centrifuge tubes and spun for 4 min (900 × g). The pellet was suspended in 30 ml of 1.6 M sucrose solution and centrifuged for 45 s (190 × g). The supernatant was passed through the 20-μm mesh filter. The sucrose extraction process of oospores was repeated five times to maximize oospore extraction. Materials caught on the 20-μm mesh filter were washed with water into a 50-ml tube and spun for 4 min (900 × g). The pellet was suspended in 1 ml of water, and the number of oospores was determined with a haemocytometer. The relationship between number of oospores recovered from the soil and number of oospores incorporated into the soil was Ŷ = –0.95 + 1.31X – 0.03X2 (R2 = 0.98), in which Ŷ = log10 of number of oospores recovered from the soil and X = log10 of number of oospores incorporated into the soil. The oospores were germinated after treatment with 0.1% KMnO4 solution for 10 min to induce germination. On the basis of the detection of ribosomal DNA, a QPCR method for P. capsici oospores was developed. PCR inhibitors were eliminated by extracting oospores from the soil by sieving-centrifugation. DNA was extracted and quantified from P. capsici oospores with suspensions of 101, 101.5, 102, 102.5, 103, 103.5, 104, 104.5, and 105 oospores per ml of water. The relationship between the DNA quantities and number of P. capsici oospores was Ŷ = –3.57 – 0.54X + 0.30X2 (R2 = 0.93), in which Ŷ = log10 (nanogram of P. capsici DNA) and X = log10 (number of oospores). The relationship between the quantity of DNA of P. capsici oospores recovered from the soil and the number of oospores incorporated into the soil was determined by Ŷ = –3.53 – 0.73X + 0.32X2 (R2 = 0.955, P < 0.05), in which Ŷ = log10 (DNA quantity of P. capsici oospores recovered from the soil) and X = log10 (number of P. capsici oospores incorporated into the soil). Utilizing the sieving-centrifugation and QPCR methods, oospores of P. capsici were quantified in soil samples collected from commercial fields.

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

Plant Disease ◽

10.1094/pdis.1998.82.3.294 ◽

1998 ◽

Vol 82 (3) ◽

pp. 294-299 ◽

Cited By ~ 33

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.

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Study of Microwave Technique in Hot Pepper Seed by Different Solvents with an Assessing Antioxidant and Antibacterial Properties

Polytechnic Journal ◽

10.25156/ptj.v11n1y2021.pp80-86 ◽

2021 ◽

Vol 11 (1) ◽

pp. 80-86

Author(s):

Holem H. Balaky ◽

Yaseen Galali ◽

Eyyüp Karaoğul ◽

Ertuğrul Altuntaş ◽

Nabil H. Rasol ◽

...

Keyword(s):

Free Radical ◽

Antioxidant Properties ◽

Inhibition Zone ◽

Chili Pepper ◽

Total Phenol ◽

Total Flavonoid ◽

Butylated Hydroxytoluene ◽

Hot Pepper ◽

Total Anthocyanin ◽

Pepper Seed

Chili pepper seed (CPS) is rich in nutrients and phytochemical particularly oil which could possess antimicrobial and antioxidant properties. Using novel techniques such as microwave assisted extraction (MAE) with solvents could be useful to extract these materials. The objectives of this study are to develop and evaluate antioxidants (and antibacterial activities of the hot seed pepper oil extracts using both water and ethanol solvents with MAE as novel techniques in relation to its ability to extract antioxidant and antibacterial compounds. Chili pepper seed (CPS) was obtained from the Kahramanmaraş, Turkey. CPS was extracted with water and ethanol and assessed for anti-oxidants activity via assessing total tannin, total phenol, total flavonoid and total anthocyanin and antimicrobial properties via assessing inhibition zone and minimum inhibitory concentration. Both yield extraction and total anthocyanin values extracted with water were 38.4 and 40.075% respectively and are higher significantly (p<0.01) higher than ethanolic extraction. On the other hand, total tannin, total phenol and total flavonoid values were 0.0575, 1.80700 and 0.26350 μM respectively which were significantly (p<0.01) higher with ethanol extraction. Ethanol had the greater free radical scavenging activity (IC 50 µg/ml) and more close standard butylated hydroxytoluene. Antimicrobial results indicated that water extracts was more effective against Staphylococcus aureus Pseudomonas aeruginosa, Enterococcus faecalis, Enterobacter aerogenes up to 24mm inhibition zone but, it is dose dependent. CPS oil extracts could be used as source of antimicrobial and antioxidants compounds with the aid of MAE. Ethanol has better yield and anthocyanin extraction and Free radical, whereas water extraction has effective antimicrobial activity.

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Effect of Red Light Treatment of Seedlings of Pepper, Pumpkin, and Tomato on the Occurrence of Phytophthora Damping-off

HortScience ◽

10.21273/hortsci.37.4.678 ◽

2002 ◽

Vol 37 (4) ◽

pp. 678-681 ◽

Cited By ~ 16

Author(s):

S.Z. Islam ◽

M. Babadoost ◽

Y. Honda

Keyword(s):

White Light ◽

Phytophthora Capsici ◽

Red Light ◽

Dry Weight ◽

Light Treatment ◽

Bell Pepper ◽

Infested Soil ◽

Damping Off ◽

Soil Mix ◽

Seedling Infection

A study was conducted in the greenhouse to investigate the effects of red light (600-700 nm) on the subsequent occurrence of seedling infection of bell pepper, pumpkin, and tomato caused by Phytophthora capsici. Three- or 4-week-old seedlings were inoculated with zoospores or transplanted into pots filled with artificially infested soil mix. Red light treatment of seedlings reduced Phytophthora damping-off by up to 79%. Only 21% to 36% of red light-treated seedlings became infected, whereas 78% to 100% of the control seedlings, grown either in natural daylight (NDL) or under white light (WL), became infected and died. The height, and fresh and dry weight of seedlings treated with red light were significantly higher than those grown under NDL or WL.

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