Management Of Anthracnose Research Articles

Integrated management of Colletotrichum gloesporioides in yellow passion fruit (Passiflora edulis f. flavicarpa Degener)

Anthracnose (Colletotrichum gloeosporioides) is one of the most limiting diseases of yellow passion fruit, reducing crop production by more than 80%. This research aimed to assess anthracnose management strategies on yellow passion fruit crop sanitation and yield. We assessed the effect of alternating fungicide applications (//) every 15 days with foliar nutrients on the severity of anthracnose and crop yield in a commercial crop in San Isidro district (Montería), located at coordinates 8°44'52.7'' N, 75°52'53.2''W and 75m.a.s.l. We conducted this research in two experiments; in the first, we assessed the response of the disease index (DI) after the application of the following treatments: T1=Manazeb (Mancozeb) // Potassium phosphite (Foscrop), T2=Mancozeb // Potassium (Terramin potassium), T3=Mancozeb // Calcium (Terramin calcium), T4=Trichoderma spp. (Fitotripen) // Copper oxychloride, T5=Azoxystrobin (Amistar) // Mancozeb, and T6=Control sprayed with water. In the second experiment, we selected the best treatments, as follows: T1 = Amistar // Mancozeb; T2 = Terramin potassium // Mancozeb, and T3 = Control. We evaluated DI, percent of affected fruits, number of fruits/ha, and yield (Kg/ha). The results from the first experiment showed that T1 and T5 controlled anthracnose, reducing the levels of severity by 39.69% compared to the control (T6). In the second experiment, T1 decreased the levels of foliage severity by 29.04% and increased the number of fruits/ha and yield by 200% compared to the control. Overall, the fungicide application of Azoxistrobin alternating with Manazeb constitutes an effective alternative to control anthracnose in yellow passion fruit cultivation.

Effect of Pyrisoxazole on Colletotrichum scovillei Infection and Anthracnose on Chili.

Anthracnose caused by Colletotrichum scovillei is one of the most destructive diseases affecting chili production. Disease control mainly relies on conventional fungicides, and repeated exposure to single-site mode-of-action fungicides may pose a risk for the development of resistant isolates within the population. Our previous study suggested that pyrisoxazole has strong inhibitory activity against C. scovillei in vitro. However, the effects of pyrisoxazole on the C. scovillei infection process and the performance of pyrisoxazole in the field remain unclear. In this study, pyrisoxazole exhibited strong inhibitory activity against the mycelial growth, appressorium formation, and appressorium diameter of C. scovillei, with half maximal effective concentration values of 0.1986, 0.0147, and 0.0269 μg/ml, respectively, but had no effect on sporulation, even at the highest concentration of 1.6 μg/ml. The baseline sensitivity curves were unimodal with a long right-hand tail. The in vivo data showed that pyrisoxazole provided both preventive and curative activity against anthracnose on chili. Pyrisoxazole decreased the incidence of anthracnose and reduced disease progress. The results of electron microscopy showed that pyrisoxazole can affect the C. scovillei infection process by altering mycelial morphology, degrading conidia and germ tubes, suppressing conidial germination and appressorium formation, and enhancing conidiophore production. Pyrisoxazole can be used to effectively control anthracnose under field conditions and increase chili yield; moreover, no phytotoxicity symptoms were observed after treatment. These results provide new insight into the mechanisms by which pyrisoxazole controls disease and suggest that pyrisoxazole is a feasible alternative for the management of anthracnose in chili.

ESTRATEGIAS DE CONTROL BIOLÓGICO UTILIZADAS PARA EL MANEJO DE LA ANTRACNOSIS CAUSADA POR Colletotrichum gloeosporioides EN FRUTOS DE MANGO: UNA REVISIÓN SISTEMÁTICA

<p>The mango (<em>Mangifera indica</em> L.) is one of the most produced tropical fruits in the world, however, during post-harvest it is affected by pathogens such as <em>Colletotrichum gloeosporioides</em>, which causes mango anthracnose. Synthetic fungicides are generally used to control this disease, but prolonged use can cause health and environmental effects; Therefore, biological control emerges as an alternative for the management of this disease, given that it is considered an effective and safe technique. The objective of this study was to describe the biological control strategies used for the management of anthracnose caused by <em>C. gloeosporioides</em> in mango fruits from a systematic review of the scientific literature. The ScienceDirect, Scopus and Scholar Google databases were used. It was found that the largest number of publications were made in 2013 and 2017, with Ataúlfo and Tommy Atkins as the most studied mango varieties and Mexico was the country with the highest number of articles reported. The most studied biological control mechanism was the effect of functional groups of microorganisms on mycelial growth and the highest percentages of inhibition were reported for this mechanism, although the greatest number of reports on control mechanisms were of the category of antagonistic microorganisms. It is concluded that knowledge about the mechanisms used to control anthracnose will allow adopting more effective, practical and reliable measures; thus, managing to maintain mango quality during the storage, distribution and marketing period.</p>

Efficacy of aroma compounds for postharvest management of mango anthracnose

Anthracnose is a severe disease of mango caused by Colletotrichum gloeosporioides Penz. The antifungal effects of the aroma compounds (trans-cinnamaldehyde, citral, and phenylacetaldehyde) were tested against the pathogen. These compounds exhibited complete inhibition of visual spore germination and the mycelial growth under in vitro conditions. Complete inhibition of mycelial growth of C. gloeosporioides was observed by trans-cinnamaldehyde (TCA) at 500 mg L−1 followed by citral (CT) at 750 mg L−1 and phenylacetaldehyde (PAA) at 2000 mg L−1. The effect of aroma compounds on the morphology and membrane lesion of C. gloeosporioides mycelia was studied through scanning electron microscopy (SEM). SEM observations revealed withered hyphae. Further experiments confirmed that aroma compounds inhibited the ergosterol synthesis and also triggered the membrane-active mechanism. Results on testing the efficacy of the aroma compounds through the fungal pectinase inhibition study confirmed that these aroma compounds have potential to damage plasma membrane integrity and cause membrane lesion of C. gloeosporioides, thereby causing the delayed anthracnose incidence in treated mango fruits as compared to control fruits. The antifungal activity of these aroma compounds could be attributed to the disruption of membrane integrity and leakage of cellular components. Results of the in vivo study showed that postharvest treatment of these compounds revealed that both disease incidence and severity efficiently managed in a dosage-dependent manner. The aroma compounds TCA, CT, and PAA might be an excellent natural and biodegradable bio-fungicides for the control of anthracnose disease in mango after harvest.

Antifungal activity of volatile compounds produced by Staphylococcus sciuri strain MarR44 and its potential for the biocontrol of Colletotrichum nymphaeae, causal agent strawberry anthracnose

A nonpathogenic endophytic bacterial isolate, recovered from Fragaria × ananassa stolon, and its antifungal activity against Colletotrichum nymphaeae was evaluated under in vitro, in vivo, and greenhouse conditions. Bacterial isolate was identified as Staphylococcus sciuri MarR44 (Strain ID: WDCM 891 = CCSM-B 00640) using phenotypic and biochemical properties and molecular phylogenetic analysis of the 16S rDNA gene sequences. The living cells of strain MarR44 inhibited mycelial growth of C. nymphaeae (52.46%) using dual-culture method. The volatile compounds (VOCs) produced by MarR44 inhibited mycelial growth and conidial germination of C. nymphaeae by 34.52% and 82.81%, respectively. However, inhibition percentage of mycelial growth of pathogen by culture filtrates of the strain MarR44 was lower (23.07%) than that for the two dual culture and volatile compounds assay tests. Moreover, the cell-free-culture filtrates of this strain reduced the biomass and conidial germination of pathogen by 91.89% and 41.10%, respectively. Also, the strain MarR44 was capable of producing protease, chitinase, HCN, siderophore, IAA, gibberellin, and biofilm. The living cells and volatile compounds of the strain MarR44 reduced anthracnose disease at post-harvest on fruit by 52.45% and 72.17%, respectively. Furthermore, disease severity of strawberry anthracnose was reduced using drenching soil and inoculated plants methods by 77.77 and 72.22%, respectively, 60 days after inoculation. The VOCs released by strain MarR44 were analyzed by Gas chromatography-mass spectroscopy (GC–MS). Out of 24 identified VOCs, Mesityl oxide (81.436%), Acetic acid, 2-methylpropyl ester (3.442%), 4-Methyldecane (1.837%), 4-Penten-2-one,4-methyl- (1.739%), Toluene (1.248%), and o-Xylene (1.24%) were the major components. The mode of action of S. sciuri MarR44 on the C. nymphaeae was through the production of antifungal volatile compounds (Antibiosis), which inhibited mycelial growth and conidial germination of pathogen in vitro and fruit decay development in vivo. To the best of our knowledge, this is the first report of S. sciuri having antifungal activity against causal agent strawberry anthracnose. These results indicated that the VOCs of S. sciuri strain MarR44 are promising biofumigant for management of strawberry anthracnose.

Role of Adjuvants in the Management of Anthracnose-Change in the Crystal Morphology and Wetting Properties of Fungicides.

The hydrophobic wax layer of pepper fruit (Capsicum frutescens L.) increases the importance of selecting adjuvants that improve the wetting property of droplets on the target organism and increase the effective utilization of fungicides. In this study, the effect of adjuvants including nonionic, cationic, organosilicone, and oils on the wettability of fungicides was determined. The critical micelle concentrations for S903 (organosilicone), 1227 (cationic), AEO-5 (nonionic), GY-Tmax (oil), and XP-2 (oil) were 25, 1000, 100, 200, and 500 mg/L, respectively. Interface behaviors and in vivo tests suggested that adjuvants at appropriate concentrations (S903, 2.5 mg/L; 1227, 100 mg/L; AEO-5, 1 mg/L; GY-Tmax, 50 mg/L; and XP-2, 5 mg/L) resulted in optimum efficiency. Adjuvants significantly increased the inhibitory activity of pyraclostrobin against the mycelial growth, spore germination, and germ tube elongation of Colletotrichum scovillei by 41.3-58.8%, 28.2-44.6%, and 27.8-39.8%, respectively. Pyraclostrobin amended with S903 and XP-2 showed higher efficacy against anthracnose than the fungicide alone on pepper fruit. The increased efficacy may have resulted from the changed crystal morphology (ellipses of similar sizes), improved wettability, and rainfastness. A structural equation model indicated that surface tension and retention play the most important roles in the application properties of fungicide. In field experiments, the efficacy of pyraclostrobin with adjuvants showed no significant difference with pyraclostrobin alone, which indicated that, except for adjuvants, other spraying technologies are important for improving the field performance of fungicides. These results provide a foundation for the synthesis of highly efficient fungicides based on crystal structure and for the sustainable management of pepper anthracnose.

Genome Sequence Resource of the Wide-Host-Range Anthracnose Pathogen Colletotrichum siamense.

Colletotrichum siamense causes fruit or foliar disease called anthracnose on a variety of plant hosts such as vegetables, fruits, ornamental plants, and others, including chili pepper, apple, American cranberry, mango, orange, papaya, guava, rubber plant, jasmine, coffee berry, and tea plants. Here, we report the first Illumina-sequenced draft genome assembly of C. siamense strain ICMP 18578 and its annotation. This genome sequence provides a unique resource that will be useful for future research on the evolution of Colletotrichum spp. and improvement of anthracnose management strategies.

Efficacy and economics of fungicides for management of mango anthracnose

Mango anthracnose, caused by Colletotrichum gloeosporioides Penz., has become a potentially destructive disease both under field and post harvest storage conditions. To devise effective management strategy against mango anthracnose, twenty fungicides were evaluated both under in vitro and in vivo conditions. In vitro evaluation studies indicated that propiconazole 25% EC, azoxystrobin 25% EC, trifloxystrobin 25% WG + tebuconazole 50% WG, azoxystrobin 25% EC + difenoconazole 25% EC and pyraclostrobin 12.8% WG + boscalid 25.2% WG completely inhibited the mycelial growth of C. gloeosporioides. Field evaluation studies revealed that three consecutive sprays at 15 days interval, starting from the first appearance of disease, with trifloxystrobin 25% WG + tebuconazole 50% WG (@ 0.04%) was found most effective in lowering the disease severity up to 6.78% in comparison to 62.11% in unsprayed check and also enhanced the fruit yield (106 kg/plant). The most economic fungicide were trifloxystrobin + tebuconazole and azoxystrobin 25% EC + difenoconazole 25% EC with cost–benefit ratio of 1:16.57 and 1:10.04, respectively.

Induction of resistance to Colletotrichum truncatum in lima bean

ABSTRACT: Anthracnose (Colletotrichum truncatum) is one of the major diseases of the lima bean culture, found in production fields, causing decrease in productivity. The objective of this study was to evaluate the effect of abiotic and biotic inducers applied in lima bean plants to reduce anthracnose severity. Lima bean accessions were used and treated with: the abiotic inducers calcium silicate (Agrosilício Plus) and silicate clay (Rocksil), using the 3 g dose.L-1; the biotic inducer citric biomass extract (Ecolife), at the dose of 3 mL.L-1; and distilled water as control. To evaluate the resistance induction, the results of severity and degree of resistance of fava bean at 7, 11, 15, 19 and 23 days after inoculation were considered according to the scale of grades and classes of reactions. The design was a randomized block in a factorial arrangement 4 × 15 (treatments × hits) with four blocks. Resistance inducers Agrosilicon Plus, Ecolife and Rocksil have potential to be used in the management of anthracnose in fava bean. The studied accesses showed degree of resistance, being able to be explored in relation to obtaining anthracnose resistant cultivars in future breeding programs of this crop.

Genetic variation of Colletotrichum magnum isolated from Carica papaya as revealed by DNA fingerprinting.

Mexico is one of the five largest producers of papaya worldwide, but losses caused by pathogens, mainly fungus, at the pre- and post-harvest stages are often more than 50% of the crop. Papaya anthracnose, caused by three different species of the Colletotrichum genus in Mexico, occupies a preponderant place in this problem. Although two of these species, C. gloeosporiodes and C. truncatum, have been characterized morphologically and genotypically, this has not occurred with C. magnum, the third species involved, about which there is very little information. Because of this, it is vital to know its genetic characterization, much more so considering that the studies carried out on the other two species reveal a wide genetic diversity, differences in pathogenicity and in the response to fungicides of the different strains characterized. In this work, Colletotrichum spp. isolates were collected at different papaya orchards in the south-southeast of Mexico. C. magnum isolates identified by species-specific primers were characterized by morphological and molecular approaches. Differences in colony characteristics resulted in five morphological groups. AP-PCR, DAMD and ISSR markers were found to be very efficient for revealing the interspecific variability of this species. The high genetic variability found in the accessions of C. magnum was linked to the geographical area where they were collected. Isolates from Chiapas State were the most variable, showing point mutations in the ITS1-ITS2 region. These results will enable a better phytosanitary management of anthracnose in papaya in this region of Mexico.

Efficacy of citronella essential oil for the management of chilli anthracnose

The potential of citronella essential oil for the management of chilli anthracnose caused by Colletotrichum acutatum was investigated. In in vitro tests, citronella essential oil inhibited mycelial growth at 0.25, 1.25 and 2.5 μL citronella/mL water, reduced conidial germination, and inhibited germ tube elongation at 1.25 μL/mL. Citronella essential oil applied as a protective or curative treatment to chilli cv. Django fruits reduced anthracnose infection. Efficacy of citronella essential oil was substantially effective to chemical fungicides and relatively superior to a biofungicide in both protective and curative tests. However, citronella essential oil at 2.5 μL/mL was phytotoxic to chilli fruits. Therefore, the most effective rate of citronella essential oil was at 1.5 μL/mL with inhibition of pathogen growth, reduction of anthracnose symptoms, and no observable phytotoxic response on chilli fruits. Citronella essential oil may be a viable alternative to chemical fungicides for the management of chilli anthracnose.

Hydrothermal treatment in the management of anthracnose in ‘Prata-Anã’ banana produced in the semiarid region of Minas Gerais, Brazil

Abstract Anthracnose stands out among rot diseases that can occur in the post-harvest phase of banana. The aim of this study was to evaluate the thermotherapy in the control of anthracnose in ‘Prata Anã’ banana produced in northern state of Minas Gerais. Bananas ‘Prata Anã’ variety were divided into groups of three fruits and inoculated with Colletotrichum musae. Groups were submitted to thermotherapy using five temperatures (40°C, 44°C, 48°C, 52°C and 56°C) and four immersion times (4, 8, 12 and 16 minutes) and control. Treatments were repeated five times in a completely randomized design. Area under the incidence progress curve (AUIPC) and area under the severity progress curve (AUSPC) were calculated. To evaluate the thermotherapy efficiency compared to chemical control, fruits were submitted to the following treatments: thermotherapy with and without fungicide application and fruits treated with fungicide only, the control fruits without thermotherapy and without fungicide application. After fifteen days of storage, fruits were evaluated for anthracnose severity. The results of experiments were submitted to analysis of variance and regression and means were compared by the Scott-Knott test (p<0.05). Control was compared to treatments by the Dunnett test (p<0,05). The lowest anthracnose AUIPC values were observed when using temperature of 48°C for eight and 12 minutes. Thermotherapy at 52°C from eight minutes of immersion, in addition to reducing the anthracnose AUSPC in fruits up to 81.6%, delayed maturation of fruits. Fruits submitted to thermotherapy at 56°C presented higher severity of the disease and resulted in the maturation of fruits. Thermotherapy reduces anthracnose severity in fruits in a manner similar to fungicide use, but the association of both results in better control of the disease in ‘Prata Anã’ banana. Thermotherapy is an efficient technique to reduce the severity of the disease in ‘Prata Anã’ banana produced in northern state of Minas Gerais.

Toxicity and biochemical action of the antibiotic fungicide tetramycin on Colletotrichum scovillei

Tetramycin, a novel polyene macrolide antibiotic, has strong activity against a broad spectrum of fungi and may have potential uses in future agricultural applications. Thus, the antifungal activity and biochemical action of tetramycin on Colletotrichum scovillei were investigated in this study. The experimental results indicated that tetramycin had strong inhibitory activity against the mycelial growth, spore germination and germ tube elongation of C. scovillei. The baseline sensitivity curves were unimodal, with mean EC50 values of 1.98 ± 0.078 μg/mL and 0.003 ± 0.005 μg/mL for mycelial growth and spore germination inhibition, respectively. Tetramycin also inhibited the germination of spores and formation of appressoria. After tetramycin treatment, the edge of the mycelial diaphragm showed protuberances, with decreased offshoots at the top. Additionally, disruption of the membrane was detected through an increase in membrane permeability, leakage of sugars and a reduction in the ergosterol content. Tetramycin effectively controlled C. scovillei on detached pepper fruits. These results will contribute to our evaluation of the potential of tetramycin for successful management of pepper anthracnose and to our understanding of the possible biochemical action of tetramycin against C. scovillei.

Effect of Plant Extracts on the Postharvest Quality and Management of Pepper Anthracnose Incited by Colletotrichum capsici (Synd) Butler and Bisby on Pepper (Capsicum frutescens L.) Fruits

Effect of Plant Extracts on the Postharvest Quality and Management of Pepper Anthracnose Incited by Colletotrichum capsici (Synd) Butler and Bisby on Pepper (Capsicum frutescens L.) Fruits

The Effects of Host Diversity in Anthracnose Management and Race Composition of Colletotrichum sublineolum in Sorghum Lineage Mixtures

The Effects of Host Diversity in Anthracnose Management and Race Composition of Colletotrichum sublineolum in Sorghum Lineage Mixtures

Residue analysis of newer fungicidal molecule Azoxystrobin 8.3% w/w + Mancozeb 64.75 w/w and management of Anthracnose of Grapes

Residue analysis of newer fungicidal molecule Azoxystrobin 8.3% w/w + Mancozeb 64.75 w/w and management of Anthracnose of Grapes

Widespread Resistance to QoI Fungicides of Colletotrichum acutatum from Strawberry Nurseries and Production Fields

Strawberry anthracnose, caused mainly by the Colletotrichum acutatum species complex, is a major disease in strawberry nurseries and production fields. The use of fungicides, such as the quinone outside inhibitors (QoIs), has been extensively deployed for the control of C. acutatum for the past 20 years. C. acutatum resistance to the QoIs was first reported in 2013 in Florida strawberry production fields. In 2015, anthracnose outbreaks were reported in strawberry nurseries and production fields across the United States. To elucidate the significance and geographical extension of C. acutatum resistance, fungicide use surveys were conducted, and isolates were collected in the affected areas. QoI-resistant isolates were collected from strawberry production fields and nurseries in six states in the United States. Fungicide use surveys indicated that, in some locations, the number of QoI applications exceeded the recommendation for this fungicide group. Thus, the current situation warrants immediate changes in anthracnose management strategies that integrate other chemical as well as nonchemical strategies to limit resistant population selection and prevent future anthracnose outbreaks.

English

English

Sensitivity of Colletotrichum acutatum to six fungicides and reduction in incidence and severity of chili anthracnose using pyraclostrobin

Anthracnose, caused by Colletotrichum acutatum, is one of the most destructive diseases of chili worldwide. Fungicides including picoxystrobin, azoxystrobin, difenoconazole, thiophanate-methyl and mancozeb have been used to manage anthracnose diseases for many years. Pyraclostrobin was introduced in China in 2016 to control chili anthracnose but has not seen widespread use. In this study, 40 isolates of C. acutatum were examined for their corresponding sensitivities to these fungicides using mycelial growth and spore germination assays. In greenhouse and field trials, the duration of protection of chili fruit from infection provided by pyraclostrobin against C. acutatum was determined. In vitro experiments showed that pyraclostrobin and azoxystrobin were inhibitory to both mycelial growth and spore germination, while mancozeb was only effective in inhibiting spore germination, and difenoconazole and thiophanate-methyl were effective in inhibiting mycelial growth. The results obtained suggest that these fungicides inhibited C. acutatum. It was observed that germ tube elongation and sporulation were reduced by pyraclostrobin. Pyraclostrobin provided protective activity for up to 96 h before inoculation, as well as curative activity up to 72 h after inoculation. In field trials, pyraclostrobin was effective in reducing the incidence and severity of anthracnose, and enhanced the marketable yield of chili. These results demonstrate that pyraclostrobin is a useful fungicide for the management of chili anthracnose.

Assessment of the baseline sensitivity and resistance risk of Colletotrichum acutatum to fludioxonil

Anthracnose, which is caused by Colletotrichum acutatum, is a destructive disease of pepper. A preliminary study demonstrated that fludioxonil (a phenylpyrrole fungicide) has good activity against C. acutatum and thus has potential to be used as an alternative fungicide for the management of pepper anthracnose. However, there is no information regarding the baseline sensitivity and resistance risk of C. acutatum to fludioxonil. Thus, the sensitivities of 205 isolates of C. acutatum to fludioxonil were determined. The results showed that the frequency distributions of the EC50 values were unimodal, and the mean EC50 values for the inhibition of mycelial growth and spore germination were 0.031 μg/mL and 0.035 μg/mL, respectively. Three stable mutants with high resistance to fludioxonil were obtained in the laboratory. Two parameters, namely in vitro sporulation and the in vitro and in vivo germination of spores, showed significant difference (P < 0.01) when the mutants were compared to the sensitive isolates. Moreover, the mutants were more sensitive to osmotic stress compared to the parents. No significant differences (P ≥ 0.05) were detected in colony diameter, mycelia weight, pathogenicity or sporulation in vivo between the fludioxonil-resistant mutants and their corresponding parents. Cross-resistance occurred between fludioxonil, iprodione and procymidone. Overall, resistance risk of C. acutatum to fludioxonil was low to medium, and thus resistance management should be considered.