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A Protocol Suggested for Management of Cantaloupe Downy Mildew
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
1-10
Received:
20 August 2014
Accepted:
25 August 2014
Published:
5 September 2014
Abstract: The inhibitory effect of the fungicides Acrobat copper, Previcure-N and Unilax, the inducer resistance chemicals (IRCs) bion, chitosan, salicylic acid and zinc sulphate and the bioagents Bacillus polymyxa, B. subtilis and Pseudomonas fluorescens on sporangial germination of fungus like Pseudoperonospora cubensis, the causal of cantaloupe downy mildew was tested in vitro. The role of the tested fungicides, IRCs and bioagents on management of cantaloupe downy mildew was evaluated under greenhouse conditions. In addition, the alternation between the sprayed tested fungicide Unilax, IRC chitosan and bioagent P.fluorescens on management of the disease under field conditions was investigated. The inhibitory effect of the tested fungicides, IRCs and bioagents on sporangial germination of P. cubensis revealed that they caused significant reduction to the germinated sporangia. The tested fungicides were the most efficient ones followed by the bioagents then IRCs. Disease management showed the same trend of in vitro experiment when they sprayed on artificially inoculated cantaloupe plants with the sporangia of the causal fungus like under greenhouse conditions. Under field conditions, spraying cantaloupe plants with the tested fungicide Unilax still the most efficient trial for management the disease during 2012 and 2013 growing seasons compared with spraying any of IRC (chitosan) and the bioagent (P. fluorescens) alone . However, spraying the tested fungicide in alternation with the tested IRC and the bioagent ranked the second efficiency of disease management. Meanwhile, spraying the tested fungicide in alternation with any of the tested IRC and bioagent was of moderate efficiency.
Abstract: The inhibitory effect of the fungicides Acrobat copper, Previcure-N and Unilax, the inducer resistance chemicals (IRCs) bion, chitosan, salicylic acid and zinc sulphate and the bioagents Bacillus polymyxa, B. subtilis and Pseudomonas fluorescens on sporangial germination of fungus like Pseudoperonospora cubensis, the causal of cantaloupe downy mild...
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Effect of Volatile and Non-Volatile Compounds of Trichoderma spp. on Botrytis Fabae the Causative Agent of Faba Bean Chocolate Spot
Barakat F. M.,
Abada K. A.,
Abou-Zeid N. M.,
El-Gammal Y. H. E.
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
11-18
Received:
20 August 2014
Accepted:
25 August 2014
Published:
5 September 2014
Abstract: Antagonistic fungi naturally occurring on faba bean leaf surface were isolated and evaluated for their activity as bioagents for Botrytis fabae the causative agent of chocolate spot disease. Thirty isolates were purified and identified as 26 isolates of Trichoderma species (Trichoderma album, T. aureoviride , T. hamatum, T. harzianum and T. viride) and 4 isolates belonging to the genera of Cladosporium, Gliocladium, Epicoccum and Paecilomyces. The inhibitory effect of these isolates was assessed in vitro against the growth of B. fabae, which decreased it's mycelial growth on PDA plates. The inhibitory effect of Trichoderma spp. ranged between 51.11 - 77.78%. In addition, T. album (Isolate 2) gave the highest inhibition followed by T. harzianum (Isolate 6). Furthermore, under greenhouse conditions spraying of faba bean plants with any of Trichoderma spp. and Bio- Zeid as a biofungicide, 24 h before inoculation with B. fabae significantly reduced the severity of the disease after 14 days in the range of 3.0 - 4% compared with the control (8.7%). T. album (Isolate 2) was the highest antagonistic isolate (3.0%) followed by T. harzianum (Isolate 6) then T. hamatum (Isolate 6) and T. viride (Isolate 2), being 3.24, 3.30 and 3.40%, respectively. Volatile and non-volatile compounds produced by T. album (Isolate 2) exhibited the highest inhibition to the mycelial growth of B. fabae followed by T. harzianum (Isolate 6).
Abstract: Antagonistic fungi naturally occurring on faba bean leaf surface were isolated and evaluated for their activity as bioagents for Botrytis fabae the causative agent of chocolate spot disease. Thirty isolates were purified and identified as 26 isolates of Trichoderma species (Trichoderma album, T. aureoviride , T. hamatum, T. harzianum and T. viride)...
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Management Fusarium Wilt of Sweet Pepper by Bacillus Strains
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
19-25
Received:
7 November 2014
Accepted:
12 November 2014
Published:
25 November 2014
Abstract: Isolation trials from the roots of wilted sweet pepper plants yielded Alternaria spp., Fusarium oxysporum, Pythium spp., Rhizontonia solani , Sclerotium rolfsii and Trichoderma spp. The isolates of the fungus F. oxysporum were selected to test their pathogenicity and Kalubia isolate was the most virulent one. The fungus was virulent to sweet pepper and low infection was found in case of the other five tested plants. Therefore, the fungus F. oxysporum named Fusarium oxysporum f.sp. capsici. All the five Bacillus strains, i.e. Bacillus chitinosporus ,B. coagulans , B. humilus ,B.subtilis and B. thuringiensis caused significant reduction to the radial growth of F.o.f.sp.capsici compared with control treatment. In addition, the growth of the tested pathogen was completely inhibited by B.subtilis and B.thuringiensis at the concentration of 60%. Furthermore, B.thuringiensis was the most efficient bioagent in this regard followed by B.subtilis then B.pumilus. Adding the three tested bioagents ,i.e.B.pumilus .B.subtilis and B. Thuringiensis to soil infested with F.o.f.sp.capsici resulted in significant reduction to sweet pepper wilt with significant increase to the plant height as well as the number of pods and their weight / plant compared with control treatment. The symptoms of the disease were obvious both on the foliage growth and the xylem vesicles, but the severity of the disease was more higher on the xylem vesicles than on the foliage growth. In addition, plants grown in soil infested with Bacillus strains were of high values of plant height and fruit yield (number and weight / plant) than that grown in the control (uninfested soil). The total phenolic compounds were greatly increased in the bacterial treated plants as compared to untreated plants with the bioagents and that infested with the pathogen only. These results give a potential of these bacterial strains for use as plant protection agents against Fusarium wilt of sweet pepper. This work was performed to investigate the potential of some bacterial bioagents ,i.e. B. humilus , B.subtilis and B. thuringiensis on management of sweet pepper Fusarium wilt and the formation of phenolic compounds in the plants.
Abstract: Isolation trials from the roots of wilted sweet pepper plants yielded Alternaria spp., Fusarium oxysporum, Pythium spp., Rhizontonia solani , Sclerotium rolfsii and Trichoderma spp. The isolates of the fungus F. oxysporum were selected to test their pathogenicity and Kalubia isolate was the most virulent one. The fungus was virulent to sweet pepper...
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Effect of Combination between Bioagents and Antioxidants on Management of Tomato Powdery Mildew
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
26-32
Received:
18 November 2014
Accepted:
21 November 2014
Published:
25 November 2014
Abstract: Isolation of microorganisms occurring on the phyllopane of tomato leaves yielded many Basillus and Trichoderma strains. The isolated Bacillus spp. were purified and identified as B. chitinosporus, B. megaterium, B. pumilus, B. subtilis and B. thuringiensis and the isolated Trichoderma spp. were, T. album, T. hamatum, T. koningii, T. harzianum and T.veredi. All the tested Bacillus and Trichoderma strains caused significant inhibition to the germinated conidia of Leveillula taurica (imperfect stage = Oidiopsis taurica) the causal of tomato powdery mildew compared with control treatment. In addition, B. thuringiensis B. subtilis and B. chitinosporus were the most efficient bacteria in this regard and T. harzianum and T. veredi were the most efficient fungi. The inducer resistance chemicals (IRCs) bion, chitosan, humic acid, salicylic acid and zinc sulphate resulted in significant reduction to the germinated conidia of the causal fungus compared with control treatment. This reduction was gradually increased by increasing the tested concentration. In plastic house experiments, spraying tomato plants with the tested bioagents B. thuringiensis and T. harzianum and the IRC salicylic acid resulted in significant reduction to powdery mildew severity during 2012/2013 and 2013/ 2014 growing seasons. Spraying of the bioagents B.thuringiensis and T. harzianum and the IRC salicylic acid, each alone or in different combinations, resulted in significant reduction to the severity of the disease with significant increase to the produced fruit yield. Furthermore, spraying any of these compounds alone was of less effect in this regard compared with spraying their combinations. However, the fungicide Sumi-8 was the superior in this regard, being 3.7 % disease severity and fruit yield 16.2 k g. / plant followed by the mixture of the three treatments, being 4.6% disease severity and fruit yield 13.7 kg. / plant. The three oxidative-reductive enzymes, i.e. PAL, PO and PPO were greatly increased in the leaves of all sprayed treatments compared with control treatment. In addition, plants sprayed with salicylic acid recorded the highest activity of the three enzymes followed by that sprayed with B. thuringiensis then T. harzianum. Meanwhile, untreated leaves (control) recorded the lowest activity followed by that sprayed with Sumi-8.
Abstract: Isolation of microorganisms occurring on the phyllopane of tomato leaves yielded many Basillus and Trichoderma strains. The isolated Bacillus spp. were purified and identified as B. chitinosporus, B. megaterium, B. pumilus, B. subtilis and B. thuringiensis and the isolated Trichoderma spp. were, T. album, T. hamatum, T. koningii, T. harzianum and T...
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Controlling of Mango Powdery Mildew by some Salts, Growth Regulators and the Biofungicide AQ10 Compared with Punch Fungicide in Egypt
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
33-38
Received:
24 December 2014
Accepted:
28 December 2014
Published:
10 January 2015
Abstract: Two experiments on 10 years old mango trees, Saddeka cv. (high susceptible cultivar) were conducted under field condition during 2012 and 2013 growing seasons for management of powdery mildew at El Adleia district, Belbees county, El-Sharkia governorate. In these trials, mango trees were sprayed with two potassium phosphate salts , calcium chloride ,three commercial growth regulators ,i.e. Agrotone (NAA), Cultar (paclobutrazol) , and Berelex (GA3), the bio-fungicide AQ10 (Ampelomyces quisqualis) , the commercial systemic fungicide Punch (flusilazole) and an alternate among Cultar ( paclobutrazol ), monobasic phosphate and the fungicide Punch. The aforementioned treatments were applied at 14 days intervals during both growing seasons starting at bud flower burst stage till full bloom stage in order to evaluate their efficiency on management mango powdery mildew disease. The obtained results showed that spraying of mango trees ( Saddeka cv.) during 2012 and 2013 growing seasons with any of the tested treatments significantly reduced the severity of powdery mildew with significant increase to the produced fruit yield compared with control treatment.In addition, results of both seasons revealed that alternation spray among Cultar ( paclobutrazol ), mono basic potassium phosphate and the fungicide Punch was the most superior treatment in reducing severity of the disease and producing the highest fruit yield followed by spraying of the fungicide Punch then spraying of mono basic potassium phosphate . Meanwhile, Brelex was of the lowest efficiency treatment in this regard followed by spraying of Agrotone . The other treatments recorded intermediate figures. Control treatment recorded 44.3 % disease severity and produced poor fruit yield.
Abstract: Two experiments on 10 years old mango trees, Saddeka cv. (high susceptible cultivar) were conducted under field condition during 2012 and 2013 growing seasons for management of powdery mildew at El Adleia district, Belbees county, El-Sharkia governorate. In these trials, mango trees were sprayed with two potassium phosphate salts , calcium chloride...
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Effect of Combination among Bioagents, Compost and Soil Solarization on Management of Strawberry Fusarium Wilt
Abada K. A.,
Faten M. Abd-El-Latif,
Hala A.M. El-Dakar
Issue:
Volume 2, Issue 6-2, December 2014
Pages:
39-46
Received:
17 December 2014
Accepted:
25 December 2014
Published:
1 February 2015
Abstract: Isolation trials from strawberry plants showing mainly wilt symptoms grown at Behera, Ismailia, Kalubia and Giza governorates yielded Fusarium oxysporum , F.solani , Macrophomina phaseolina , Pythium ultimum , Phytophthora cactorum , Rhizoctonia solani and Sclerotium rolfsii . Pathogenicity test of the four isolates of F.oxysporum revealed that they caused wilt symptoms and Kalubia isolate was the most virulent one. In addition, inoculating different seven plants, i.e. bean, cucumber, eggplant, sweet pepper, strawberry, tomato and water melon with F. oxysporum isolate of Kalubia governorate indicated that it caused wilt symptoms to strawberry plants only. Therefore, it named Fusarium oxysporum f.sp. fragariae Winks & Y.N. Williams. Four isolates of Bacillus spp., i.e. Bacillus coagulans , B.humilus , B.subtils and B. thringiensis and one isolate of Pseudomonas flurescens were isolated from the rhizospheric soil of strawberry plants grown in a field have severe infection by Fusarium wilt were screened for their efficacy against F. o. f.sp. fragariae, in vitro and in vivo. In general, P.flurescens followed by Bacillus subtilis were the most efficient in reducing the linear growth of the pathogenic fungus. Sterilized aqueous filtrate of the tested compost resulted in significant reduction to the linear growth of the tested fungus compared with control treatment. This reduction was gradually increased by increasing it׳s concentration. The combination among the bioagents B.subtilis and P.flurescens, compost and soil solarization resulted in significant reduction to strawberry Fusarium wilt with significant increase to the produced fruits and their total soluble solids (T.S.S.) , either each of them was used alone or in their different combinations, compared with control treatment (infested with the causal fungus).On the other hand, compost was the most efficient in this regard compared with the other three items of disease management, i.e. soil solarization and the bioagents B.subtilis and P.flurescens when each of them was used alone. Moreover, no apparent infection was detected when the bioagents B.subtilis and P.flurescens ,compost and soil solarization were used together and produced fruit yield of T.S.S., to somewhat, similar to control treatment ( uninfested soil with the causal fungus).
Abstract: Isolation trials from strawberry plants showing mainly wilt symptoms grown at Behera, Ismailia, Kalubia and Giza governorates yielded Fusarium oxysporum , F.solani , Macrophomina phaseolina , Pythium ultimum , Phytophthora cactorum , Rhizoctonia solani and Sclerotium rolfsii . Pathogenicity test of the four isolates of F.oxysporum revealed that the...
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