scholarly journals Effect of <i>Trichoderma asperellum</i> and <i>Trichoderma virens</i> on <i>Allium cepa</i> L. Growth, Damping off and Basal Rot Disease Incidence and Severity in Sri Lanka

2020 ◽  
Vol 6 (3) ◽  
pp. 40
Author(s):  
Lankeswarage Nilupa Rasangi Gunaratna ◽  
Nelum Deshappriya ◽  
Sirimewan Rajapaksha ◽  
Dehiwala Liyanage Jayaratne
2019 ◽  
Vol 6 (2) ◽  
pp. 275-292
Author(s):  
L. N. R. Gunaratna ◽  
◽  
N. Deshappriya ◽  
D. L. Jayaratne ◽  
R. G. S. A. S. Rajapaksha ◽  
...  

2017 ◽  
Vol 14 (1) ◽  
pp. 22-31
Author(s):  
Baghdad Science Journal

This study was conducted to determine the fungal cause and bio control of damping off and root rot of wheat plants by using pseudomonas fluorescens under greenhouse and field conditions. Results showed isolation of eight species from the soil and roots to deferent region of Baghdad government. Rhizoctonia solani (Rs) and Fusarium solani (Fs) were the predominant damping off fungus with frequency 60 and 52% respectively. Led the using of bacteria formulations such as crud suspension , pure bacteria filtration and pure living cells in culture medium inhibit all type fungi with rates ranging from 84-96% , 80- 93% and 75-88% respectively. Rs and Fs were more pathogenesis under greenhouse conditions, with incidence of 80 and 68% and disease severity up to 41,20 and 30,20% respectively. The results of test bacterial formulation (dry, liquid and bacterial filtrate ) with seeds, soil and water irrigation showed high effectiveness for all treatments with superiority of the treatment of seeds in reducing the incidence which reached for the three formulation 21-34% compared with the infested control of Fs, Rs which reached 70 and 55%, respectively. Field experiments results showed superiority of seeds bacterization with dry formulation to reduce the disease incidence to 38% compared with the infested control (75%).These results reflected on the increasing of the shoot and rot dry weight and increasing the productivity (63%) compared with the infested control treatment .


2021 ◽  
Vol 7 (3) ◽  
pp. 195
Author(s):  
Amr H. Hashem ◽  
Amer M. Abdelaziz ◽  
Ahmed A. Askar ◽  
Hossam M. Fouda ◽  
Ahmed M. A. Khalil ◽  
...  

Rhizoctonia root-rot disease causes severe economic losses in a wide range of crops, including Vicia faba worldwide. Currently, biosynthesized nanoparticles have become super-growth promoters as well as antifungal agents. In this study, biosynthesized selenium nanoparticles (Se-NPs) have been examined as growth promoters as well as antifungal agents against Rhizoctonia solani RCMB 031001 in vitro and in vivo. Se-NPs were synthesized biologically by Bacillus megaterium ATCC 55000 and characterized by using UV-Vis spectroscopy, XRD, dynamic light scattering (DLS), and transmission electron microscopy (TEM) imaging. TEM and DLS images showed that Se-NPs are mono-dispersed spheres with a mean diameter of 41.2 nm. Se-NPs improved healthy Vicia faba cv. Giza 716 seed germination, morphological, metabolic indicators, and yield. Furthermore, Se-NPs exhibited influential antifungal activity against R. solani in vitro as well as in vivo. Results revealed that minimum inhibition and minimum fungicidal concentrations of Se-NPs were 0.0625 and 1 mM, respectively. Moreover, Se-NPs were able to decrease the pre-and post-emergence of R. solani damping-off and minimize the severity of root rot disease. The most effective treatment method is found when soaking and spraying were used with each other followed by spraying and then soaking individually. Likewise, Se-NPs improve morphological and metabolic indicators and yield significantly compared with infected control. In conclusion, biosynthesized Se-NPs by B. megaterium ATCC 55000 are a promising and effective agent against R. solani damping-off and root rot diseases in Vicia faba as well as plant growth inducer.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Assefa Sintayehu ◽  
Seid Ahmed ◽  
Chemeda Fininsa ◽  
P. K. Sakhuja

Shallot (Allium cepaL. var.ascalonicum) is the most traditional vegetable crop in Ethiopia. Shallot is susceptible to a number of diseases that reduce yield and quality, among which fusarium basal rot (FBR) caused byFusarium oxysporumf.sp.cepae (Foc)is one of the most important yield limiting factors in Ethiopia. The present study was designed to evaluate the effectiveness ofBrassicacrops for the management of shallot FBR on shallot. The experiments were carried out at Debre Zeit Agricultural Research Center using cabbage (Brassica oleracea), garden cress (Lepidium sativum), Ethiopia mustard (B. carinata), and rapeseed (B. napus). The evaluations were done underin vitroand greenhouse conditions. Underin vitrotest condition it was confirmed that extracts of Ethiopian mustard and rapeseed showed higher inhibition on the growth ofFocpathogen compared to control. Data on seedling emergence, plant height, plant stand, disease incidence, severity, cull bulbs, and bulb weight were collected in greenhouse experiment. The green manure amendments of rapeseed and Ethiopian mustard significantly reduced disease incidence by 21% and 30% and disease severity by 23% and 29%, respectively. However the plant emergency was not significantly different among treatments in greenhouse test. These results indicated that Ethiopian mustard and rapeseed crops have potential as green manure for the management of FBR disease of shallot crop.


2014 ◽  
Vol 11 (10) ◽  
pp. 1841-1859 ◽  
Author(s):  
Fabien Fonguimgo Tengoua ◽  
Mohamed M. Hanafi ◽  
A. S. Idris ◽  
Kadir Jugah ◽  
Jamaludin Nurul Mayziatul Azwa ◽  
...  

Plant Disease ◽  
2010 ◽  
Vol 94 (1) ◽  
pp. 125-125 ◽  
Author(s):  
G. Polizzi ◽  
D. Aiello ◽  
I. Castello ◽  
V. Guarnaccia ◽  
A. Vitale

Mediterranean fan palm (Chamaerops humilis L.), one of just two autochthonous European palms, is native to the western Mediterranean Region in southwestern Europe and northwestern Africa. It can be found growing wild in the Mediterranean area. In Europe, this species is very popular as an ornamental plant. In March 2009, a widespread damping-off was observed in a stock of approximately 30,000 potted 1-month-old plants of C. humilis cv. Vulcano in a nursery in eastern Sicily. Disease incidence was approximately 20%. Disease symptoms consisted of lesions at the seedling shoot (plumule). Stem lesions were initially orange, turned brown, and followed by death of the entire plumule or eophyll. A fungus with mycelial and morphological characteristics of Rhizoctonia solani Kühn was consistently isolated from lesions when plated on potato dextrose agar (PDA) amended with streptomycin sulfate at 100 μg/ml. Fungal colonies were initially white, turned brown with age, and produced irregularly shaped, brown sclerotia. Mycelium was branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells removed from cultures grown at 25°C on 2% water agar were determined to be multinucleate when stained with 1% safranin O and 3% KOH solution (1) and examined at ×400. Anastomosis groups were determined by pairing isolates with tester strains AG-1 IA, AG-2-2-1, AG-2-2IIIB, AG-2-2IV, AG-3, AG-4, AG-5, AG-6, and AG-11 on 2% water agar in petri plates (3). Anastomosis was observed only with tester isolates of AG-4, giving both C2 and C3 reactions (2). One representative isolate obtained from symptomatic tissues was deposited at the Fungal Biodiversity Centre, Centraalbureau voor Schimmelcultures (CBS No. 125095). Pathogenicity tests were performed on container-grown, healthy, 1-month-old seedlings. Twenty plants of C. humilis cv. Vulcano were inoculated near the base of the stem with two 1-cm2 PDA plugs from 5-day-old mycelial cultures. The same number of plants served as uninoculated controls. Plants were incubated in a growth chamber and maintained at 25°C and 95% relative humidity on a 12-h fluorescent light/dark regimen. Symptoms identical to those observed in the nursery appeared 5 days after inoculation and all plants died within 20 days. No disease was observed on control plants. A fungus identical in culture morphology to R. solani AG-4 was consistently reisolated from symptomatic tissues, confirming its pathogenicity. To our knowledge, this is the first report in the world of R. solani causing damping-off on Mediterranean fan palm. References: (1) R. J. Bandoni. Mycologia 71:873, 1979. (2) D. E. Carling. Page 37 in: Grouping in Rhizoctonia solani by Hyphal Anastomosis Reactions. Kluwer Academic Publishers, the Netherlands, 1996. (3) C. C. Tu and J. W. Kimbrough. Mycologia 65:941, 1973.


2020 ◽  
Vol 14 (1) ◽  
pp. 339-344
Author(s):  
Sabah R. Mohammed ◽  
Ivan D. Eskov ◽  
Elsayed M. Zeitar

Background: Fusarium dry rot disease caused by Fusarium sambucinum Fuckel (F. sambucinum) can infect the potato tubers in the field and during storage. Yield losses by F. sambucinum reach 60%. Traditional methods to control Fusarium dry rot are fungicides application, which led to developing many isolates resistant to these fungicides. Objective: The aim of this study is to evaluate the effect of calcium chloride (CaCl2) and chitosan, alone or in combination, on plant development, tuber yield, and Fusarium dry rot disease incidence under field conditions. Methods: Soil inoculated with F. sambucinum before planting. We treated the seed tubers with CaCl2 (0.5 or 1%), chitosan 0.5%, or both. The foliage was sprayed twice with CaCl2 (0.5 or 1%), 0.1% chitosan, or both. During the vegetation period, growth parameters, such as germination (%), plant height (cm), and branches number per plant, were measured. At harvest, we calculated the total and the marketable number of tubers and tuber yield. In addition, during storage, we assessed the incidence of Fusarium dry rot disease on tubers. Results: Results revealed that combined pre-planting application with 1% CaCl2 and 0.5% chitosan with 2 hours intervals, then spraying foliar with 1% CaCl2 and 0.1% chitosan twice with ten days intervals starting at 40 days after planting resulted in: a) increasing the germination, enhancing the growth parameters such as plant height and branches number per plant; b) enhancing the marketable tuber yield by 75.2 and 97.6% in Sante and Kolobok varieties, respectively; c) reducing Fusarium dry rot disease incidence by 61.9-72.7%. Conclusion: The work highlighted that the combined pre-planting and foliar application of CaCl2 and chitosan might be recommended for potato producers to reduce the incidence of Fusarium dry rot disease and augment yields.


Plant Disease ◽  
2003 ◽  
Vol 87 (5) ◽  
pp. 601-601 ◽  
Author(s):  
S. T. Koike ◽  
T. R. Gordon ◽  
B. J. Aegerter

In 1999 and 2000, greenhouse-grown leek (Allium porrum) transplants produced in coastal California (Monterey County) developed a root and basal rot. Affected roots were initially gray and water soaked in appearance and later became pink, soft, and rotted. Basal plates were also affected, becoming water soaked and rotted. Severely affected transplants grew poorly and had chlorotic older leaves; many of these plants collapsed. Disease incidence varied greatly, though some transplant plantings had more than 50% disease. Similar symptoms were found in commercial, field-planted leek crops in the same region. The problem caused significant economic loss to transplant producers because of the loss of plants and the reduction in quality of surviving infected plants. Isolations from transplant and field samples consistently recovered a Fusarium species from both root and basal plate tissues. Single-spore subcultures were grown on carnation leaf agar and incubated under fluorescent light. All isolates produced abundant macroconidia that were stout, thick walled, and had prominent septa. Foot cells were indistinct to slightly notched. Conidiophores were monophialidic. Microconidia were absent and chlamydospores were present. Colonies on potato dextrose agar produced abundant, dense, white, aerial mycelium. The undersurface of these cultures was carmine red. Based on these features, all isolates were identified as Fusarium culmorum. To confirm the identification, a partial sequence (645 bp) of the translation elongation factor (EF-1α) was obtained for one isolate using primers EF-1 and EF-2 (2). The EF-1α sequence from the leek isolate was identical to that of two F. culmorum isolates in Genbank (Accession Nos. AF212462 and AF212463). The next closest match was F. cerealis, which differed from the leek isolate at six nucleotide positions. To test pathogenicity of the leek isolates of F. culmorum, we prepare inocula of four isolates from transplants and three isolates from field plants. A conidial suspension (1 × 105 conidia/ml) of each isolate was applied to the roots of 3-month-old potted leek (cvs. Autumn Giant, Blauwgroene, and Cisco). For the control treatment, leek plants were treated with water. All plants were maintained in a greenhouse at 25°C. After 1 month, inoculated plants showed foliar and root symptoms similar to those observed on the original samples. F. culmorum was reisolated from these symptomatic plants. Control plants did not develop symptoms. Using the same procedures, the seven isolates were inoculated onto other Allium species, but did not cause any symptoms on shallot (A. cepa var. ascalonicum) or eight cultivars of onion (A. cepa). Two of the seven isolates caused slight root symptoms on garlic (A. sativum). All experiments were conducted two times and the results of both tests were similar. To our knowledge, this is the first report of a root and basal rot of leek in California caused by F. culmorum. The occurrence of this disease on transplants grown in a soilless rooting medium and on raised benches in enclosed greenhouses provides circumstantial evidence that the pathogen could possibly be seedborne. This disease was reported recently in Spain (1). References: (1) J. Armengol et al. Plant Dis. 85:679, 2001. (2) K. O'Donnell et al. Proc. Natl. Acad. Sci. 95:2044, 1998.


2021 ◽  
Vol 24 (2) ◽  
pp. 107-120
Author(s):  
SMN Islam ◽  
SS Siddique ◽  
MZH Chowdhury ◽  
NJ Mishu

A native Trichoderma isolate was collected from the agricultural soil of Gazipur. This isolate was identified as a Trichoderma asperellum through morphology and analysis of internal transcribed spacer (ITS) region of ribosomal RNA gene sequence and reconstruction of the phylogenetic tree. The antagonistic effects of the newly identified T. asperellum isolate were assessed against brinjal bacterial wilt caused by Ralstonia solanacearum both in vitro and in planta. Both qualitative and quantitative bioassays were conducted in vitro. For qualitative tests, dual culture and antibacterial activity were carried out, and pathogen growth was observed visually. The antagonism of T. asperellum cell free culture filtrate on the growth of R. solanacearum was conducted in a quantitative test. Successful antagonism was recorded after both in vitro qualitative tests. In addition, the lowest colony forming unit was recorded in 100% of CFC (2.4±0.51 ×103 cfu/ml) in quantitative test. The T. asperellum inoculated plant showed low disease incidence (13.33%) when seedlings were challenged with R. solanacearum in planta experiment. Disease incidence was 100% for seedlings when treated with only R. solanacearum. The results showed that the isolated and identified T. asperellum isolate suppressed R. solanacearum growth in vitro and protected the seedling from wilting in planta. Therefore, this isolate could be considered as a potential isolate. Ann. Bangladesh Agric. (2020) 24(2) : 107-120


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