scholarly journals Incidence of leaf blight disease of Egusi melon in South-west Nigeria

2020 ◽  
Vol 28 (2) ◽  
pp. 255-265
Author(s):  
J.F. Ogunsola ◽  
B. Ikotun ◽  
K.E. Ogunsola
Keyword(s):  
Fungal Pathogens ◽  
Citrullus Lanatus ◽  
Disease Incidence ◽  
Leaf Blight ◽  
Economic Damage ◽  
Colletotrichum Truncatum ◽  
Southwestern Nigeria ◽  
Lasiodiplodia Theobromae ◽  
Ondo State ◽  
Blight Disease

Egusi melon (Citrullus lanatus (Thumb) Mansf.) is an important vegetable crop grown for edible seeds and oil in West Africa. Leaf Blight Disease (LBD) is one of the major constraints to its production, with potential to cause economic damage. The objective of this study was to investigate the incidence and distribution of leaf blight on Egusi melon in Southwestern Nigeria. A survey of LBD of Egusi melon was conducted in 2015 and 2016, in five southwestern States of Nigeria (Ogun, Oyo, Osun, Ekiti and Ondo States). Twenty plants each, were randomly sampled from 150 farms comprising 30 farms each, from each State. The distribution of different Egusi melon varieties planted was recorded. “Bara” cv. was the most cultivated variety (51.6%); followed by “Bojuri” (30.4%) and “Serewe” (18%). Leaf blight was observed in most farms in the five States, from 73% in Osun and Oyo states to 83% in Ondo State. Disease incidence and severity varied with locations and cultivars, and ranged from 0.0-87.5±18% and 1.0±0-4.5±0.8 in Osun State to 20.0±19 - 95.0±4.5% and 2.3±1.5 - 5.0±0 in Ondo State. Out of the twelve fungal pathogens from ten genera isolated from infected plants, only Colletotrichum truncatum, C. gloeosporioides and Lasiodiplodia theobromae caused Leaf blight on Egusi melon. Key words: Colletotrichum gloeosporioides, Colletotrichum truncatum, Lasiodiplodia theobromae

Is Lasiodiplodia theobromae the only species that causes leaf blight disease in Brazilian coconut palms?

2020 ◽  
Vol 45 (4) ◽  
pp. 434-442
Author(s):  
Pedro H. D. Santos ◽  
Beatriz M. Carvalho ◽  
Fernanda A. S. Aredes ◽  
Vicente Mussi-Dias ◽  
Danilo B. Pinho ◽  
...  
Keyword(s):  
Leaf Blight ◽  
Lasiodiplodia Theobromae ◽  
Blight Disease

scholarly journals Prevalence and Severity of Leaf Blight Disease of Chrysanthemum in Southern regions of Karnataka and in-vitro Fungicidal Effect on Alternaria alternata

2015 ◽  
Vol 9 (3) ◽  
pp. 38-45 ◽  
Author(s):  
G. Shamala ◽  
G. R. Janardhana
Keyword(s):  
Alternaria Alternata ◽  
Disease Incidence ◽  
Life Sciences ◽  
Leaf Blight ◽  
Cut Flowers ◽  
In Vitro Evaluation ◽  
Karnataka State ◽  
Commercially Important ◽  
Blight Disease

Chrysanthemum is one of the commercially important flower crop with great potential both as loose and cut flowers in Karnataka state. In the present study, prevalence and incidence of leaf blight disease was studied in six major growing districts of South Karnataka during 2012 - 2013. The pathogen associated with leaf blight disease was isolated and identified as Alternaria alternata. The study revealed that, the disease was distributed in Southern districts of Karnataka wherever Chrysanthemum is grown. The varieties Chandini and Karnel were more susceptible to blight showing highest disease incidence (100%) and severity (100%) recorded from Mandya and Mysore regions. The lowest disease incidence, severity and PDI of 18.40%, 38.68% and 24.89% were recorded on Rajawhite variety in Bangalore region. During 2013, the highest disease incidence, severity and PDI with 100%, 98.47%, and 45.71% were recorded in Mysore district on Chandini variety. In vitro evaluation of four fungicides on Alternaria alternata revealed that Carbendazim+Mancozeb was most effective with 95.65% inhibition followed by Carbendazim, Mancozeb and Metalaxyl+Mancozeb with 68.26%, 91.30% and 91.30% inhibition of the mycelium at 2.0% concentration.DOI: http://dx.doi.org/10.3126/ijls.v9i3.12465   International Journal of Life Sciences 9 (3): 2015; 38-45

scholarly journals Assessing Taro (Colocasia esculenta (L.) Schott) Leaf Blight Incidence, Severity, and Farmers’ Knowledge of the Disease in Fako Division of Cameroon

2020 ◽  
pp. 17-29
Author(s):  
Mandah Cicelia Takor ◽  
Ekwa Yawa Monono ◽  
Ojong Agbor Ntane ◽  
Jemimah Evenye Ngale ◽  
Lum A. Fontem
Keyword(s):  
Disease Severity ◽  
Disease Incidence ◽  
Management Strategies ◽  
Leaf Blight ◽  
Cultural Methods ◽  
Randomized Design ◽  
High Prevalence ◽  
Severity Of The Disease ◽  
Blight Disease ◽  
Taro Leaf Blight

Taro leaf blight (TLB), a major disease of taro plant caused by Phytophthora colocasiae, a pseudo-fungus, that occurs in many taro producing areas, especially in the South West of Cameroon. A Survey was conducted to assess farmers’ knowledge, as well as to determine the incidence and the severity of the disease in taro fields. Structured questionnaires were administered in selected locations (Bokova, Ekona, Muea, Mile 16, Mutengene, and Likomba) of taro production. Two farms were selected with two quadrats of 64 m2 each were carved to assess disease incidence and severity on taro. The number of plants infected with taro leaf blight were counted and the area of the affected leaves measured was used to evaluate the disease incidence and disease severity. Data collected were subjected to ANOVA for complete randomized design and the means were compared using Tukey test at 0.05 probability levels. The results revealed that most of the farmers could identify the disease while practicing cultural methods in controlling the disease. The results also revealed significant differences (p = 0.001) in disease incidence and disease severity in all the localities, with Mile 16 showing the highest percentage mean of 96.53% and 85.59%, respectively. The severity scored showed high infection range of 3 – 3.95 in all locations except in Likomba (2.60).  It could be concluded from the results that there were high prevalence of taro leaf blight disease in Fako Division. Good management strategies are therefore required to control Taro leaf blight and improve taro production in the area.

First Report of Macrophomina phaseolina, Fusarium brachygibbosum, and Lasiodiplodia theobromae Causing Fungal Watermelon Vine Decline in Southwest and West-Central Florida

2021 ◽  
Author(s):  
Cristina Pisani ◽  
Scott Adkins ◽  
William W Turechek ◽  
Pragna C Patel ◽  
Erin Rosskopf
Keyword(s):  
Disease Severity ◽  
Fungal Pathogens ◽  
Disease Incidence ◽  
Macrophomina Phaseolina ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Central Florida ◽  
Untreated Check ◽  
Vine Decline ◽  
Yellowing Virus

Wilt and vine decline symptoms were observed on watermelon plants in Glades and Hardee Counties in Florida in spring 2017 that resembled viral watermelon vine decline caused by squash vein yellowing virus (SqVYV). When no SqVYV was detected, greenhouse studies and morphological and molecular analyses revealed three fungal pathogens, Macrophomina phaseolina, Fusarium brachygibbosum, and Lasiodiplodia theobromae, that were not previously reported on watermelon in Florida. A previously reported oomycete, Pythium spinosum, was also detected in some, but not all isolates, and but when applied independently, resulted in disease incidence that was comparable to the untreated check, ruling it out as a primary causal agent of the symptoms observed in the field. In one of three experiments, seedlings inoculated with a combination of Macrophomina phaseolina, Fusarium brachygibbosum, and Pythium spinosum suffered the highest disease severity based on AUDPC values. In another experiment, seedlings inoculated with F. brachygibbosum exhibited the most severe symptoms and rapid disease development following inoculation. When seeds were inoculated with either a single or a combination of the isolated fungi, those inoculated with L. theobromae resulted in seedlings with the greatest disease severity. This is the first report of these three fungal pathogens on watermelon in Florida.

scholarly journals Incidence and management of Colletotrichum gloeosporioides canker on Jatropha curcas L. in Ibadan, southwestern Nigeria

2020 ◽  
Vol 24 (10) ◽  
pp. 1811-1814
Author(s):  
J.O. Nwogwugwu ◽  
A.A. Batcho ◽  
I Time
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Laboratory Data ◽  
Plant Diseases ◽  
Economic Losses ◽  
Dual Culture ◽  
Southwestern Nigeria ◽  
Environmental Consequences ◽  
Randomized Design ◽  
The Impact

The Impact of fungal pathogens on man is enormous, stretching from infecting humans to destroying a third of all food crops annually thereby causing economic losses and impacting global poverty. As a result, fungal disease incidence was assessed under natural field infection and data were collected randomly from 12 months old jatropha seedlings with cankers. Colletotrichum spp. isolated from the diseased sampled were interacted with known fungi and bacteria biocontrol agents. The experiment was carried out on completely randomized design (CRD) in the laboratory. Data were analyzed using ANOVA and statistically different means were separated using LSD (p≤0.05). The dual culture interaction proved that all the BCA used, possessed antagonistic potential, and could serve best for prophylactic protection. Plant diseases may be suppressed by the activities of one or more plant-associated microbes hence keeping them in check below threshold levels. This will help to maintain the quality and abundance of food, thereby mitigating hunger. Negative environmental consequences caused by excessive use and misuse of agrochemicals, requires that healthier and costeffective approaches to disease management should be adopted. Keywords: Biodiesel; Agrochemicals; Biocontrol agent; Dual culture; Pathogens

scholarly journals SKRINING DAN IDENTIFIKASI ISOLAT BAKTERI ENDOFIT UNTUK MENGENDALIKAN PENYAKIT HAWAR DAUN BAKTERI PADA BAWANG MERAH

2013 ◽  
Vol 13 (2) ◽  
pp. 167-178
Author(s):  
Zurai Resti ◽  
Trimurti Habazar ◽  
Deddi Prima Putra ◽  
Nasrun Nasrun
Keyword(s):  
Bacillus Cereus ◽  
Endophytic Bacteria ◽  
Disease Incidence ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Bacillus Sp ◽  
In Planta ◽  
16S Rrna Sequence ◽  
Randomized Design ◽  
Blight Disease

Screening and identification of endophytic bacteria to control bacterial leaf blight disease on Shallot. The experiment was conducted in Laboratory and Green House, from January to June 2012.   Laboratory experiment consisted of three steps:  (1) isolation of endophytic bacteria from healthy onion roots, (2)In planta /screening of endophytic isolates capable of reducing bacterial leaf blight disease, and (3) molecular identification of potential endophytic isolates.  Treatments of  in planta test were arranged in Completely Randomized Design.  Collected isolates were tested for their capability in controlling bacterial leaf blight disease on shallot.  The variables observed were disease incidence, disease severity, and shallot yield. The results showed that out of 82 isolates successfully isolated, 56 isolates (68.29%) were Gram positive, and 26 isolate (31.71%) were Gram negative. All isolates were HR negative and pathogenicity negative. Six endophytic isolates showed  better performance in inducing resistance and increasing onion yield. Based on 16S rRNA sequence the six isolates were  Bacillus cereus strain P14 , Bacillus cereus strain Se07, Bacillus sp H1, Bacillus sp SJ1 and Serratia marcescens strain PPM4.

scholarly journals Alternaria alternata and Alternaria sonchi: Two new records of fungal pathogens on Sonchus asper (annual sow thistle) in Pakistan

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Khalid Pervaiz Akhtar
Keyword(s):  
Alternaria Alternata ◽  
Fungal Pathogens ◽  
New Records ◽  
Leaf Blight ◽  
Herbaceous Plant ◽  
Disease Symptoms ◽  
Sonchus Asper ◽  
Leaf Spots ◽  
Winter Annual ◽  
Blight Disease

Sonchus asper (annual sow thistle) is an annual or winter annual herbaceous plant native to Europe. It has become a very aggressive invader in many regions of the world. In February 2013, S. asper plants grown in and around the chickpea and tomato fields at Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan were found to be severely affected by a leaf blight disease. Initially the disease symptoms began as small, circular, dark, necrotic lesions usually on the older leaves. At later stage, these lesions enlarged rapidly up to 4-12 mm in diameter and when spotting was abundant the entire leaf turned yellow. However, in April 2013, S. asper plants grown in and around the tomato and wheat fields at NIAB, Faisalabad, Pakistan were found with different leaf blight symptoms. The leaf spots were initially small, epiphyllous, irregular, scattered to marginal and dark-brown. Later on these spots enlarged, became orbicular to irregular but often angular, with brown to cinereous necrotic centers and usually with a narrow dark margin. On the basis of symptoms, morphological and cultural characteristics of the isolated pathogen, the causal agent was identified as Alternaria alternata from February infected plants while it was identified as Alternaria sonchi from April infected plants and Koch’s postulates were fulfilled. This is the first report of Alternaria alternata and Alternaria sonchi from S. asper plants in Pakistan

scholarly journals Efficacy of spraying intervals of Ridomil Plus 66 WP for control of taro leaf blight disease

1970 ◽  
Vol 29 (1) ◽  
pp. 133-140
Author(s):  
J. Adomako ◽  
N.E. Amengor ◽  
S. Larbi-Koranteng ◽  
F. Kankam
Keyword(s):  
Yield Loss ◽  
Disease Incidence ◽  
Economic Benefits ◽  
Weekly Interval ◽  
Leaf Blight ◽  
Total Revenue ◽  
Optimum Period ◽  
Blight Disease ◽  
Taro Leaf Blight ◽  
Biweekly Interval

Taro leaf blight causes up to 100% yield loss in susceptible taro (Colocasia esculenta L. (Schott)) cultivars. The use of fungicides in disease management is fast and effective; however efficacy of fungicides could be affected by frequency of application. The objective of this study was to evaluate the efficacy of spraying intervals and economic benefits of Ridomil Plus 66 WP (12% Metalaxyl-M and 60% Copper (1) oxide) on taro leaf blight disease. The study consisted of four fungicide spraying intervals, viz at one, two and at four weekly intervals, all at the concentration of 3.3 g l-1 and no fungicide application as the control. Results showed no significant differences (P > 00.5) between one and two weekly spraying intervals in terms of taro leaf blight disease incidence and severity. These were, however, significantly different (P < 0.05) from four weekly and no fungicide applications. Taro corm yield was higher in weekly spraying interval, but not significantly different (P > 0.05) from biweekly application intervals. Yields in weekly intervals were 2.9, 33.0 and 44.0% higher than biweekly, four weekly and no application intervals. Applying fungicide at a biweekly interval was found to be economically efficient as it recorded higher total revenue and net present values. Applying 66 WP (12% Metalaxyl-M and 60% Copper (1) oxide) at 2 weekly interval was the optimum period and most efficient to reduce the incidence and severity of Phytophthora leaf blight disease and increase yield of taro.

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