Control Of Anthracnose Research Articles

In vitro response of Colletotrichum to chitosan. Effect on incidence and quality on tropical fruit. Enzymatic expression in mango

Colletotrichum is considered one of the fungal genera with the greatest diversity of species of phytopathogenic fungi and with a wide range of hosts including tropical fruits. In this study, the concentration of chitosan applied was a key factor in the in vitro inhibition of the three Colletotrichum isolates with the most sensitive being the one from banana. Germination was the development stage most affected by the application of this polymer. At the end of 10 days of storage, control of anthracnose in soursop, mango and banana fruit was considerable with the application of 1 % chitosan, with 80 to 100 % inhibition. Likewise, the ripening process of fruit with and without chitosan was generally similar. Activity of the peroxidase (POD) and polyphenol oxidase (PPO) enzymes was observed only in fruit of mango cv. 'Tommy Atkins,' inoculated and non-inoculated with C. gloeosporioides, the activity of both enzymes was higher in the chitosan treatments and the 1.0 % concentration was able to induce gene expression of POD and PPO, occurring until 24 h.

Ripening of ‘Kumagai’ guavas and anthracnose control as affected by methyl jasmonate

ABSTRACT Methyl jasmonate (MJ) is an endogenous regulator that can influence fruit ripening and the defense system against pathogens. This work verified the influence of this regulator on postharvest physiology, control of anthracnose and physicalchemical attributes of ‘Kumagai’ guava (Psidium guajava L.). Guavas harvested at mature-green and ripe stages were treated with 0, 1 and 10 μmol∙L−1 MJ as gas in hermetic containers (200 L) with air circulation for 24 h. Fruit were inoculated with Colletotrichum gloeosporioides spore suspension (105 spores∙mL−1) 24 and 48 h after treatment. During ripening, at 25 °C and 80 – 90% of relative humidity, respiration, ethylene production, anthracnose incidence, severity and quality of guavas were assayed. Data were subjected to analysis of variance and means, compared by Tukey’s test (p ≤ 0.05 and 0.10). The application of 1 and 10 μmol∙L−1 MJ had little influence on ripening of ‘Kumagai’ guava with a slight increase in respiration, ethylene production and yellowing of fruit harvested at ripe stage. Treatments with 1 and 10 μmol∙L−1 MJ did not reduce the severity and incidence of C. gloeosporioides when applied in fruit harvested at ripe and mature-green stages and inoculated 24 or 48 h after MJ treatment. In conclusion, the MJ treatment, at 1 and 10 μmol∙L−1 concentrations, had little influence on ripening and did not control anthracnose in ‘Kumagai’ guavas.

セルリー萎縮炭疽病の生態解明と防除に関する研究

セルリー萎縮炭疽病の生態解明と防除に関する研究

Phosphites for the control of anthracnose in common bean

Abstract: The objective of this work was to evaluate the effect of phosphites in the protection of common bean (Phaseolus vulgaris) against anthracnose. Different phosphite formulations were evaluated by quantifying peroxidase and polyphenol oxidase activity, total phenols, and lignin content. The treatments consisted of sprayings, in the V4, R5, and R7 stages, with: the K, Zn, Mn, K+Mn, K+salicyclic acid, and Cu phosphites; salicylic acid; acibenzolar-S-methyl; the fungicide azoxystrobin; besides a control, without sprayings. The area under the disease progress curve was lower in plants that received applications of the K and Mn phosphites, whose values ranged between 74 and 81%, compared with the control. The K, Zn, and K+salicyilic acid phosphites were effective in controlling the disease. In addition, disease severity was lower with the application of the K, Zn, and Mn phosphites than with the control. Enzyme (peroxidases and polyphenol oxidases) activity and levels of soluble phenols were higher in common bean plants treated with the K and Mn phosphites, although no change was detected in the levels of soluble lignin in the same tissue. Phosphite application reduces the severity of the disease, can enhance enzymatic activity, and is an effective alternative for the control of anthracnose in common bean.

Comparative Reliability of Screening Parameters for Anthracnose Resistance in Water Yam (Dioscorea alata).

Anthracnose, caused by Colletotrichum gloeosporioides, is one of the major constraints limiting water yam (Dioscorea alata) production in the tropics. In this region, yam anthracnose control is mostly achieved by the deployment of moderately resistant yam genotypes. Therefore, screening for new sources of anthracnose resistance is an important aspect of yam research in the tropics. The reliability and applicability of different yam anthracnose rating parameters has not been fully examined. Disease severity on detached leaves in the laboratory and leaf severity, lesion size, and spore production on whole plants in the greenhouse were used to screen an F1 yam population and correlate screening results with field evaluations. Anthracnose lesion size had the smallest predicted residual means but whole-plant severity and detached-leaf severity had the best variance homogeneity and relatively small predicted residual means. The concordance correlation coefficient (rc) and κ statistic were used to determine the agreement between anthracnose rating parameters and field evaluations. Detached-leaf (rc = 0.95, κ = 0.81) and whole-plant (rc = 0.96, κ = 0.86) evaluations had high positive agreement with field evaluation but spore production (κ = 0.69) and lesion size (κ = 0.57) had moderate positive agreement. These results suggest that all the evaluated rating parameters can be used to successfully screen yam germplasm for anthracnose resistance but lesion size and spore production data may need to be transformed.

Foliar N Concentration and Reflectance Meters to Guide N Fertilization for Anthracnose Management of Annual Bluegrass Putting Green Turf

Site‐specific management using objective assays to determine N requirement based on canopy reflectance could improve current recommendations for cultural control of anthracnose (Colletotrichum cereale Manns sensu lato Crouch, Clarke, and Hillman). The objectives of this study were to determine the relationships among foliar sap nitrate–nitrogen (NO3–N) concentrations, canopy reflectance indices (normalized difference vegetation index [NDVI] and chlorophyll index [CI]), foliar total N concentrations, and N rate on anthracnose severity in annual bluegrass (ABG), Poa annua L. f. reptans (Hausskn) T. Koyama. A 2‐yr field study was conducted on ABG putting green turf in Storrs, CT. Nitrogen treatments were applied as urea at 0.0 to 36.8 kg ha−1 every 14 d in spring and summer of 2011 to 2012. Anthracnose severity declined linearly with increasing biweekly N rate from 0 kg ha−1 up to the estimated critical level of 12.8 kg ha−1. A minimum critical foliar N concentration of 33.5 g kg−1 maintained anthracnose at ≤32% plot area. Canopy reflectance indices were correlated with foliar N concentration. Anthracnose severity decreased linearly as relative NDVI and relative CI increased. Maintaining relative NDVI between 0.94 to 0.98 through N fertility alone would provide a ∼76 to 93% probability of maintaining ≤32% turf area infested, or relative CI range of 0.73 to 0.93 had the same result ∼40 to 98% of the time.

Management of Anthracnose in Soybean using Fungicide

Experiments on soybean (Glycine max L. Meril) were carried out aiming to control anthracnose (pod blight) caused by fungus, Colletotrichum truncatum with five treatments represented by different fungicidal sprays against control receiving no spray with three replicates of each under field conditions during two consecutive years from 2012 to 2013. In 2012, the higher Percent Disease Control (PDC) and Percent Yield Increase (PYI) were estimated in plot treated with SAAF (Carbendazim 12% + Mancozeb 63%) followed by Mancozeb fungicides. The mean Pod Infection (PI) was low in plots treated with SAAF followed by Mancozeb. Almost similar trends of disease control were observed in 2013. The lower Percent Disease Index (PDI) was 46.25% and mean PI was 29.67% with higher yield value of 2431.25 kg/ha obtained from the plots sprayed with SAAF then by Mancozeb. The results showed that, the combined treatment with fungicides, SAAF followed by Mancozeb were effective to control anthracnose or pod blight disease of soybean to increase the yield.Journal of Nepal Agricultural Research Council Vol.1 2015 pp.29-32

Cassava starch coatings for postharvest control of papaya anthracnose

The effects of coating papaya fruit ( Carica papaya ) with cassava starch were studied, to determine the best concentration and mode of action of this material in postharvest control of anthracnose. The concentrations of starch tested were 1%, 2%, 3% and 4%. These were prepared to give gel consistency. Surface sterilized papaya fruits were inoculated with conidia of Colletotrichum gloeosporioides and incubated for 48 h in a moisture chamber. The were then treated with cassava fruit gels and dried. During the following 14 d storage period, fruit maturation and anthracnose on the fruits were assessed, and electron microscopy was used to examine fruit epicarps. All cassava starch coating concentrations reduced fruit maturation and anthracnose, with the 2%, 3% or 4% coatings giving 100% disease control. The 2% starch coating is likely to be optimum, considering the lower cost efficiency of disease control. The mechanism of disease control provided by the coating is likely to be related to delay of ripening and the formation of a protective layer over the fruit.

Use of chitosan for the control of postharvest anthracnose and quality in avocados

Use of chitosan for the control of postharvest anthracnose and quality in avocados

Disease risk perception and diversity of management strategies by farmers: The case of anthracnose caused by Colletotrichum gloeosporioides on water yams (Dioscorea alata) in Guadeloupe

Disease perception and adequate management practices are two essential issues faced by farmers, especially in the current context of climate change which may potentially increase disease risk. We investigated the diversity of water yam cropping systems in Guadeloupe through interviews, how producers and international yam research scientists perceived anthracnose, and how this perception correlated with farmers’ risk management strategies. We found that disease perception by farmers is very close to perception by international yam experts, as both have the same perception of the hierarchy of factors translating into disease. Three different yam production strategies coexist at a local scale, where agronomic practices and socio-economic profiles are distinct and consistent with attitude toward anthracnose risk management. Six factors were perceived as decreasing the disease: associated crop species; crop rotation; staking; weeding; crop monitoring and varietal admixture. Yam producers raising crops more intensively were risk prone, while others usually sought practices to manage disease appearance and spread. Both cumulative risk and past anthracnose epidemic experiences translated into heavier reliance on chemicals. These results have practical implications for designing best yam crop management systems and control of yam anthracnose.

Control of Colletotrichum fructicola on strawberry with a foliar spray of neutral electrolyzed water through an overhead irrigation system

Neutral electrolyzed water (NEW: pH 6.5–7.5) applied through an overhead irrigation system was evaluated for control of strawberry anthracnose caused by Colletotrichum fructicola. Conidia of the pathogen were completely killed by a 10-s exposure to 10.0 mg/L of available chlorine in the NEW. Disease suppression was significantly higher using the NEW treatment through overhead irrigation, either alone or combined with fungicides, than using conventional fungicides. Plants had no visible phytotoxicity after the NEW treatment, even when combined with fungicides. Thus, the NEW treatment was effective at controlling anthracnose caused by C. fructicola.

Biocontrol potential of two novel grapevine associated Bacillus strains for management of anthracnose disease caused by Colletotrichum gloeosporioides

ABSTRACTA study was conducted to identify bacterial antagonists for biological control of anthracnose which is one of the economically important diseases of grapes. In India, it is caused by Colletotrichum gloeosporioides. Two hundred and ninety-three bacteria were isolated from the grape ecosystem of 43 spatially distant vineyards in peninsular India. Of these, 25 bacteria substantially inhibited the radial growth of C. gloeosporioides in in vitro studies and 18 bacteria significantly reduced infections in vivo. Of these 18 bacteria, 5 and 3 bacteria also significantly reduced percent disease index (PDI) of downy and powdery mildew diseases, respectively. These bacteria were labelled as strains, DR-38, DR-39, TL-171, DRo-198, TS-204, TS-205, and DR-219, and were identified as Bacillus species based on morphological and molecular characterisation. Aqueous suspensions of all these strains applied as foliar sprays at 1×108 cfu/ml on field grown vines significantly lowered the PDI and the AUDPC (area under disease progress curve) of anthracnose when compared with the untreated control, except DRo-198. Strains TS-204 and TL-171 recorded lower PDIs and AUDPC when compared with the other five strains, and TS-204 could effectively suppress ripe rot of berries, too, in vivo. Strains TS-204 and TL-171 are identified for biocontrol of anthracnose in grapes.

Investigation into various fungicides and alternative solutions for controlling postharvest diseases in papaya fruit

In Australia, Sportak® (a.i., prochloraz) has been registered since the early 1980's for the postharvest control of both anthracnose and stem-end rots in papaya fruit, despite the persistence of fruit breakdown due to disease during transit and at market destinations. Consequently, the Australian papaya industry has been concerned over the efficacy of prochloraz and whether substitute or alternative solutions were available for better disease control, particularly during times of peak disease pressure. This study therefore investigated the effects of various postharvest treatments for disease control in papaya. Fruit were harvested at colour break from coastal farms in Far North Queensland and treated with commercial rates of various fungicides, including prochloraz, imazalil, thiabendazole and fludioxonil. Additional solutions known to inhibit disease were examined, including chitosan and carnauba wax both with and without ammonium carbonate (AC). Following treatment, fruit were ripened and assessed for quality over their shelf life. Fludioxonil when applied as a hot dip was found to be a more efficacious treatment for control of disease in papaya than prochloraz. The other fungicides were moderately effective, as both thiabendazol and prochloraz exhibited an intermediate response and imazalil was the least effective. Disease severity was lowest in fruit treated with AC followed by chitosan, whilst chitosan delayed degreening. Overall, the study found that hot fludioxonil provided an effective replacement of the currently registered chemical prochloraz, and that alternate solutions such chitosan and AC may also be beneficial, particularly for low chemical input farming systems.

Efficacy of ginger oil and extract combined with gum arabic on anthracnose and quality of papaya fruit during cold storage.

Effect of 2.0% ginger oil (GO) and 1.5% ginger extract (GE) in combination with 10.0% gum arabic (GA) was evaluated for the postharvest control of anthracnose and maintaining quality of Eksotika II papaya fruit during storage at 12±1°C and 80-85% RH. Antifungal compounds present in GO and GE were analyzed using gas chromatography and GO was found to contain α-pinene, 1, 8-cineole and borneol, while only borneol was present in GE due to different extraction methods applied. The highest antifungal activity was shown in 2.0% GO combined with 10% GA, which significantly (P<0.05) inhibited spore germination by 93%. Based on the physicochemical properties tested, 2.0% GO combined with 10% GA significantly delayed the ripening of papaya. These results show that 10.0% GA combined with 2.0% GO is an effective postharvest biofungicide for papaya.

Fungicide association in the control of anthracnose in the soybean in Mato Grosso do Sul

The soybean is a worldwide agricultural product, and therefore justifies investments in reducing those factors that are unfavourable to production, such as anthracnose caused by Colletotrichum truncatum. Three experiments were carried out with the aim of evaluating the control of anthracnose by fungicides, either singly or in combination, in soybean shoots sown on two dates in the 2011/12 season, under the conditions found at Dourados and Maracaju in the State of Mato Grosso do Sul. An experimental design of randomised blocks with five replications was used. The treatments were: control, carbendazim 250 g a.i. ha-1, pyraclostrobin 66.5 g a.i. ha-1 + epoxiconazole 25 g a.i. ha-1, picoxystrobin 60 g a.i. ha-1 + cyproconazole 24 g a.i. ha-1, carbendazim 250 g a.i. g-1 + pyraclostrobin 66.5g a.i. ha-1 + epoxiconazole 25 g a.i. ha-1 and carbendazim 250 g a.i. ha-1 + picoxystrobin 60 g a.i. ha-1 + cyproconazole 24 g a.i. ha-1. Two fungicide applications were performed, the first when the disease was detected at development stage R2, and the second 19 days later. The following were evaluated: incidence and average severity, defoliation, plant height, first pod height, number of pods, productivity and thousand grain weight. Seed pathology was carried out focusing on the incidence of C. truncatum. The use of carbendazim, singly or combined, controlled anthracnose in the shoots and seeds of the soybean. The application of fungicides resulted in reduced defoliation, a lower percentage of diseased petioles, a greater number of pods, greater plant height and gains in productivity. Carbendazim + cyproconazole + picoxystrobin occasionally displayed greater control than did single carbendazim.

Biological control of anthracnose of soybean

Soybean (Glycine max L. Meril) is one of the most important and well recognized oil seed and grain legume crops of the world. A field experiment was conducted to investigate the efficacy of BAU-Biofungicide (Trichoderma harzianum), Trichoderma based IPM Lab bio-pesticide and Bavistin against anthracnose of soybean. Five soybean cultivars viz. Sohag, BARI Soybean-6, BINA Soybean-1, BINA Soybean-2 and BINA Soybean-3 were used in this experiment. The field experiment was carried out following Randomized Complete Block Design in the field laboratory of the Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh. Anthracnose infections were found initially lower at 80 DAS, moderate infections were found at 95 DAS and the highest infections were recorded at 110 DAS in case of all the tested five soybean varieties. The highest percent reduction of anthracnose infected plants/plot over control was observed in Bavistin treated plot (76.25%) that was near to BAU Biofungicide treated plots. All the growth parameters of soybean plants such as plant height, number of pods/plant, seed weight/plant, yield/plot and yield/ha were increased significantly in BAU-Biofungicide treated plots that showed best performance in compare to IPM Lab bio-pesticide (2%) and Bavistin @ 0.2% when these treatments were applied two times with 15 days interval. However, anthracnose incidence was reduced significantly when all the treatments applied in this experiment and the effect of BAU-Biofungicide was found almost similar to Bavistin in reduction of anthracnose of soybean.Res. Agric., Livest. Fish.2(3): 419-426, December 2015

Evaluation of the endophytic nature of Bacillus amyloliquefaciens strain GYL4 and its efficacy in the control of anthracnose.

Endophytic bacteria are viewed as a potential new source of biofungicides because they have beneficial characteristics as control agents for plant disease. This study was performed to examine the endophytic feature and disease control efficacy of Bacillus amyloliquefaciens strain GYL4 and to identify the antifungal compounds produced by this strain. B. amyloliquefaciens strain GYL4 was isolated from leaf tissue of pepper plants (Capsicum annuum L.). Anthracnose symptoms were markedly reduced in the leaves of pepper plants colonised by GYL4. An egfp-expressing strain of GYL4 (GYL4-egfp) was constructed and reintroduced into pepper plants, which confirmed its ability to colonise the internal tissues of pepper plants. GYL4-egfp was observed in the root and stem tissues 4 days after treatment and abundantly found in the internal leaf tissue 9 days after treatment. Bacillomycin derivatives purified from the culture extract of GYL4 displayed control efficacy on anthracnose development in cucumber (Cucumis sativus L. cv. Chunsim). The present study is the first report on evaluation of the endophytic and systemic nature of B. amyloliquefaciens strain GYL4 and its potential as a biocontrol agent for anthracnose management. © 2015 Society of Chemical Industry.

Caracterização de isolados de Colletotrichum spp. associados às frutíferas no Estado de São Paulo

RESUMOO Estado de São Paulo é um dos maiores produtores de frutas no Brasil. A competitividade no comércio internacional de frutas demanda a minimização de danos pós-colheita, especialmente os causados pela antracnose. Para o controle eficaz da antracnose em uma região é necessário conhecer quais espécies estão associadas a cada hospedeiro e qual a variabilidade dos agentes causais. Este trabalho objetivou caracterizar e identificar isolados de Colletotrichum de frutíferas cultivadas no Estado de São Paulo, Brasil. Foram analisados 93 isolados obtidos de abacate, manga, maracujá e pêssego, por meio de morfometria de conídios e colônias e análise molecular (amplificação por PCR com oligonucleotídeos espécie-específicos e análise de sequências de nucleotídeos das regiões ITS e β-tubulina). Alta variabilidade morfométrica foi observada entre os isolados. A análise molecular indicou que, no Estado de São Paulo, as antracnoses do abacate, manga, maracujá e pêssego podem ser causadas por diferentes espécies do complexo C. gloeosporoides, revelando também a presença de C. boninense associada à antracnose do maracujá e de espécies não identificadas dos complexos C. acutatum e C. gloeosporioides causando antracnose em pêssego.

길항세균 Bacillus sp. KBC1004를 이용한 고추탄저병의 생물학적 방제제 개발

길항세균 Bacillus sp. KBC1004를 이용한 고추탄저병의 생물학적 방제제 개발

Avaliação de fungicidas no controle de antracnose e mancha alvo, e no rendimento da cultura da soja

Soybean is one of the main crop in the world, because is a source of food products, for animals and humans, besides its use as biofuels. Although new technologies have been used in this crop, its productivity has been limited mainly by the occurrence of diseases, such as anthracnose (Colletotrichum truncatum) and target spot (Corynespora cassiicola). Thus, the aim of this work was to evaluate the efficiency of fungicides for the control of anthracnose and target spot, applied to the leaves, in a commercial area in the north of Mato Grosso State, Brazil. The experimental design was randomized blocks with eight treatments and three repetitions. The treatments were: T1- Control; T2- 1st Application: Pyraclostrobin + Epoxiconazole, 2nd Application: fluxapyroxad + Pyraclostrobin; T3- 1st Application: Azoxystrobin, 2nd Application: Azoxystrobin; T4- 1st Application: Pyraclostrobin, 2nd Application: Pyraclostrobin + Epoxiconazol; T5- 1st Application: Fluxapyroxad + Pyraclostrobin, 2nd Application: Fluxapyroxad + Pyraclostrobin; T6- 1st Application: Trifloxystrobin + Prothioconazol, 2nd Application: Trifloxystrobin + Prothioconazol; T7- 1st Application: Picoxystrobin + Cyproconazol, 2nd Application: Picoxystrobin + Cyproconazol; T8- 1st Application: Tebuconazol, 2nd Application: Tebuconazol. The first application of fungicides was at soybean flowering and the second, 15 days after the first application. There was no statistical difference among treatments to plant height, height of 1st pod, number of pods per plant and number of grains per plant. In relation to anthracnose, treatments did not differ significantly; however, treatment T2 was more efficient in controlling target spot. The treatments that increased the weight of 1000 seeds (g) were T1, T2, T5 and T6, but there was no difference among treatments for productivity (sacks ha-1).