scholarly journals Sensitivity of Colletotrichum gloeosporioides Isolates from Diseased Avocado Fruits to Selected Fungicides in Kenya

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Stanley Kirugo Kimaru ◽  
E. Monda ◽  
R. C. Cheruiyot ◽  
J. Mbaka ◽  
A. Alakonya

Colletotrichum gloeosporioides is a serious postharvest pathogen of avocado fruits worldwide. Kenya lacks any registered fungicides for the management of the disease. Nevertheless, farmers commonly use commercially available fungicides such as Bayleton 25WP (Triadimefon 250 g/Kg), Milraz 76WP (Propineb 70% and Cymoxanil 6%), and Copper oxychloride 500WP for disease management. The efficacy of these fungicides against C. gloeosporioides is not known. The purpose of this study was therefore to test the inhibitory effect of these fungicides against 46 C. gloeosporioides isolates from avocado fruits collected from varieties grown at different agroecological zones in Murang’a County, a popular avocado-growing region in Kenya. Mycelial growth rate and sporulation for each isolate were measured in vitro on PDA plates amended with different concentrations of the fungicides. Plates were arranged in a completely randomized design with three replications per treatment. All fungicides were effective in vitro but there were significant differences in sensitivity among isolates. Bayleton had the highest mycelial inhibition followed by Milraz, while copper oxychloride had the lowest mycelial inhibition rates, ranging from 81% to 88%. However, copper oxychloride was more effective in inhibiting sporulation. The inhibitory effect of each fungicide was concentration-dependent, where twice the recommended concentration had the highest inhibitory effect, followed by the recommended concentration. Our results show that the fungicides used by farmers against C. gloeosporioides, the causal agent for anthracnose, are effective. We, however, recommend further field tests in different avocado-growing areas so as to validate their efficacy against various isolates and under different environments.

2020 ◽  
Vol 8 (4) ◽  
pp. 82
Author(s):  
Cleverson Rodrigues ◽  
João Aguilar Massaroto ◽  
Grace Queiroz David ◽  
Dilânia Lopes de Matos ◽  
Walmor Moya Peres ◽  
...  

Products derived from renewable sources have been studied for their use in agriculture enabling increments in the production of agricultural culture, such as in the case of the pyroligneous extract. The research aimed at evaluating the fungitoxic potential of the pyroligneous extract of teak (Tectona grandis L.) on mycelial growth, sporulation and spore germination of Colletotrichum gloeosporioides. The experiment was conducted in completely randomized design with five treatments and four replications. Five doses of pyroligneous extract were tested (0, 25, 50, 100, 150 mL L-1) following the pour-plate methodology in 10 mL of potato dextrose agar media and kept in the incubating room maintained at 25 ± 2 °C in a 12 hour-photoperiod for eight days. Mycelial growth variables (cm), mycelial index growth speed, growth inhibition (%), sporulation inhibition (%) and spore germination (%) were evaluated. There was a reduction for the mycelial growth as well as for the rate of mycelial growth, sporulation inhibition and spore germination as the doses were increased. The percentage inhibition of mycelial growth was 56 % for the highest dose (150 mL L-1). Pyroligneous extract of teak has a direct fungitoxic action on growth, sporulation and germination in vitro of the fungus C. gloeosporioides.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Héber Ferreira dos Reis ◽  
Lilian Maria Arruda Bacchi ◽  
Silvana de Paula Quintão Scalon ◽  
Jasna Karoliny Pereira Flores

ABSTRACT: We evaluated the efficacy of natural products in the control of papaya anthracnose, in vitro and in vivo. The in vitro experiments for evaluation of mycelial growth used a completely randomized 10 × 4 factorial design (treatments × evaluation periods) with eight replicates, with sporulation evaluated at the end of the experiment. The treatments involved the use of aqueous extract at concentrations of 5 and 15% for Syzygium aromaticum (L.) Merr. & Perry (clove), Cinnamomum zeylanicum Breym (cinnamon), and Zingiber officinalis Rox. (ginger); 1 and 3% chitosan; the fungicide Prochloraz at 100 µg.mL-1; and a control (no treatment). For evaluating conidia germination, we used six treatments with five replicates. The treatments included 7.5% of each extract (clove, cinnamon, and ginger), 1.5% chitosan, and 50 µg.mL-1 of Prochloraz. For the in vivo experiment, “Formosa” papaya “Tainung 1” was used in a completely randomized design, with six treatments and four replicates to evaluate the severity of anthracnose caused by Colletotrichum gloeosporioides. The fruits were treated by immersion for 5 min with 15% clove, cinnamon, and ginger extracts, 8% chitosan, and control with distilled water, and immersion for 2 min in Prochloraz (33.75 g a.i./100 L). The treatments with 15% clove extract and 8% chitosan were effective in all evaluations, resulting in a viable alternative to the fungicide Prochloraz. The treatments with ginger extract were less effective and those with cinnamon offered intermediate control.


2021 ◽  
Vol 43 ◽  
pp. e56548
Author(s):  
Ana Carolina Botelho dos Reis ◽  
Júlia Ronzella Ottoni

White mold disease, caused by fungus Sclerotinia sclerotiorum (Lib.) de Bary., is a disease hard to control due to the high amount of sclerotia produced, which guarantees its survival in the soil for years leading to significant yield losses. Alternative techniques to control the pathogen have been researched, including homeopathy. The present work aimed to evaluate the in vitro antifungal effect of homeopathic medicines on S. sclerotiorum mycelial growth. Homeopathic medicines Sulphur, fungal sclerotium Nosode and Calcarea carbonica, in 30CH, 200CH and 1000CH dynamizations were tested. Assays were carried out in a completely randomized design, with four repetitions. Experiments were performed through the addition of homeopathic medicines on the surface of plates containing culture medium, followed by insertion of a disc containing fungus mycelia and incubation. Control treatment received no homeopathic medicine. The mycelial progression was monitored by seven halo diameter measurements during experiment period. All homeopathic medicines tested and their dynamizations were able to inhibit partially the development of the fungus. Calcarea carbonica at the dynamization of 1000 CH showed the best inhibitory effect on S. sclerotiorum, which under its effect produced a mycelial halo 40% smaller than the control treatment.


Author(s):  
Silvia Patricia López-Zapata ◽  
Jairo Castaño-Zapata

Anthracnose is considered one of the most important diseases of grape crops. In this study, we evaluated the in vitro effect on potato dextrose agar (PDA) of four fungicides: benomyl (Benlate® 50 WP), carbendazim (Belico ® 500 SC), chlorothalonil (Odeon® 720 SC), and dodine (Syllit ® 400 SC) using three concentrations on a Colletotrichum gloeosporioides isolate. This species complex causes anthracnose on the Red Globe grape variety. The concentrations of each fungicide were: benomyl at 0.5, 0.25, and 1 g.L-1; carbendazim at  0.6, 0.3, and 1.2 mL.L-1; chlorothalonil at 2.4, 1.2, and 4.8 mL.L-1, and dodine at 1.6, 0.8, and 3.2 mL.L-1. Evaluated the inhibition of mycelial growth and the sporulation of the fungus. The fungus mycelium exposed to the commercial dose of the fungicides was observed using environmental scanning electron microscopy (ESEM). We used a completely randomized design with 13 treatments and five repetitions. Our results showed a degree of differential efficacy for the four fungicides and their effects were directly proportional to the dose used, benomyl and chlorothalonil being the most efficient in controlling the mycelial growth of the fungus. At the commercial dose, sporulation was inhibited at a higher rate by benomyl showing no statistically significant differences with the other products except chlorothalonil and dodine when the recommended dose was reduced by half. The damage observed by ESEM on the fungus mycelium ratified the effect obtained in vitro, i.e., deformed hyphae and irregular growth. The results of this study, complemented by electron microscopy, are promising for the appropriate selection of the best fungicides for controlling anthracnose on grape fruits, subject to the timely and correct diagnosis of the disease.


2020 ◽  
Vol 11 (2) ◽  
pp. 69-77
Author(s):  
Cleverson Rodrigues ◽  
João Aguilar Massaroto ◽  
Grace Queiroz David Peres ◽  
Dilânia Lopes de Matos ◽  
Walmor Moya Peres ◽  
...  

The aim of this research was to evaluate the fungitoxicity of high dilutions of tectonic (Tectona grandis) extract in mycelial growth, sporulation and germination of the fungus Colletotrichum gloeosporioides. In a completely randomized design with six dynamizations of the pyroligneous extract (3, 9, 15, 21, 27 and 33 CH) and three controls (distilled water, mother tincture, 30% hydroalcoholic solution) with four replicates each. All treatments were diluted to 0.1% in BDA medium. Mycelial growth rate index, relative percentage of mycelial development (PRD%), inhibition of sporulation and spore germination (%) were evaluated. The treatments did not differ among them for mycelial growth, percentage of spore germination and IVCM. The PRD and sporulation variables varied according to the dynamization, with a maximum reduction of 7% in PRD (33 CH) and a 70% increase in sporulation (3 and 21 CH). The dynamized pirolenous extract did not present expressive fungitoxicity in the growth, sporulation and germination of C. gloeosporioides.


Author(s):  
Arneti Arneti ◽  
Eri Sulyanti

Plant extracts have been known to cause inhibit the growth of Colletotrichum gloeosporioides.This study was aimed to determine the most potential part of Cassia alata crude extract to control antrachnose on chili. The study was conducted in Phytopathology Laboratory, Plant Pests and Diseases Department, Agriculture Faculty, Andalas University, from April to June 2015. The research used Completely Randomized Design (CRD) with seven treatments and five replications. The treatments were several extracts from different parts of C. Alata: 1) control 2) flower, 3) old leaf, 4) young leaf, 5) stem, 6) root, and 7) seed with concentration of 5% respectively. Variables observed were colony growth, colony width, conidia number, colony wet and dry weight, and conidia germination. The result showed that all of C. alata extracts could inhibit the growth of C. gloeosporioides in vitro. The best extract was from the old leaf with the percentage of colony width, conidia number, colony wet and dry weight, and conidia germination of 64,30%, 82,41%, 37,77, 29,8%, and 79,96% respectively.


2020 ◽  
Vol 3 (2) ◽  
pp. 296-305
Author(s):  
Prem Bahadur Magar ◽  
Suraj Baidya ◽  
Rabina Koju ◽  
Sagar Adhikary

Spot blotch disease of wheat caused by Bipolaris sorokiniana; is one of the most concerning disease in warm and humid regions of Nepal due to its widespread prevalence and increasing severity. An in-vitro experiment was conducted to evaluate the efficacy of different botanicals and fungicides against Bipolaris sorokiniana, in National Plant Pathology Research Centre’s laboratory at Khumaltar, Lalitpur in 2019. The experiment was done in completely randomized design with three replications by poison food technique. Five botanicals viz. neem, garlic, eucalyptus, bojho and asuro at three different concentrations (5%, 10% and 15%) and eight fungicides viz. sectin, curex, bavistin, vacomil plus, saaf, sajha, criptan and tilt at three concentration levels (25 ppm, 50 ppm and 100 ppm) except curex (50 ppm, 100 ppm and 200 ppm) were used to evaluate the effect on the radial mycelial growth and mycelial growth inhibition percentage of the pathogen. The different botanical extracts and fungicides in different concentrations inhibited the mycelial growth of fungus significantly (p<0.01). The highest mycelial growth inhibition percentage was found by the application of garlic clove extract (52.85%) at 15% which was followed by bojho (52.48%) at 15% concentration. While tilt was found effective fungicide which completely inhibits the mycelial growth at all concentrations. Also, fungicides viz. sajha (79.78%), saaf (73.59%) and sectin (70%), at 100 ppm were found effective in controlling the pathogen as compare to others. Mycelial growth inhibition of the fungus was found to be increased with the increase in concentrations of botanicals and fungicides.


2010 ◽  
Vol 10 (1) ◽  
pp. 59-63
Author(s):  
Subli Mujim Mujim

Effect of  the  ginger extract (Zingiber officinale Rosc.) on the growth of Pythium sp., the causal agent of cucumber damping off disease.  The Pythium sp. often damaged cucumber seedling in seedbed.  The objective of this study was to evaluate the effectiveness of ginger extract on the growth and spore production of Pythium sp.   The study was conducted in 2005 at the laboratory of plant pathology, University of Lampung.  The treatments were arranged in a completely randomized design with four replicates.  The treatments were consisted of five level of concentrations of ginger rhizome extract i.e, 0; 2.5; 5.0; 7.5 and 10 %.    The results show that all concentrations of the rhizome ginger extract inhibited mycelial growth and spore production of Pythium sp.  There was a significant linear relationship between the rhizome  ginger extract and both of fungal growth and spore production.


2017 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Nurhasanah Nurhasanah ◽  
Fauzia Andrini ◽  
Yulis Hamidy

Shallot (Allium ascalonicum L.) has been known as traditional medicine. Shallot which has same genus with garlic(Allium sativum L.) contains allicin that is also found in garlic and has been suspected has fungicidal activity toCandida albicans. It is supported by several researches. Therefore, shallot is suspected has antifungal activity too.The aim of this research was to know antifungal activity of shallot’s water extortion againsts Candida albicans invitro. This was a laboratory experimental research which used completely randomized design, with diffusion method.Shallot’s water extortion was devided into three concentrations, there were 50%, 100% and 200%. Ketoconazole 2%was positive control and aquadest was negative control. The result of this research based on analysis of varians(Anova), there was significant difference between several treatments and was confirmed with Duncan New MultipleRange Test (DNMRT) p<0,05, there was significant difference between 100% shallot’s water extortion with othertreatments, but there was no significant difference between 50% shallot’s water extortion with 200% shallot’s. Theconclusion was shallot’s water extortion had antifungal activity againsts Candida albicans with the best concentration100%, but it was lower than ketoconazole 2%.


Agrologia ◽  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
S. Tuhuteru ◽  
Meity L Hehanussa ◽  
Simon H.T Raharjo

Dendrobium anosmum is one of natural orchids in Indonesia. Optimization of medium composition for orchid propagation through in vitro culture is necessary to enhance propagule multiplication capabilities and quality. This study was aimed to study the influence of concentration of coconut water in culture medium on in vitro growth and development of D. anosmum orchid species and to determine the optimal coconut water concentration in culture media.  The experiment were arranged in a Completely Randomized Design with four treatments and eight replications. The treatments consisted of the addition of coconut water with concentrations: 0 ml•l -1 (control), 50 ml•l-1, 100 ml•l-1 and 150 ml•l-1. The results showed that addition of coconut water in culture medium gave different effect on shoot growth and multiplication of D. anosmum orchids.  Coconut water concentration of 100 ml•l-1 was the best concentration for growth and multiplication of D. anosmum orchids, based on both shoots and roots growth, plantlet height and wet weight.


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