Control químico de la antracnosis del mango (Mangifera indica l.) en pre y postcosecha en el Municipio Cedeño, Estado Monagas, Venezuela

Bioagro 01/2007;
Source: OAI

ABSTRACT Chemical control of anthracnose during pre and postharvest in mango, in Cedeño County, Monagas State, Venezuela Currently the most important pathologies of mango in Monagas State, Venezuela, are the spots on the foliage, flower and fruits caused by anthracnose (Colletotrichum gloesporioides Penz). It has been noted that the implementation of a spraying program containing fungicides, is the most viable practice to manage the disease, due to the fact that most of the farms are established with susceptible varieties. The experiment was conducted in farm located in the area of Tarragona, Cedeño county in Monagas State, on mango trees, cultivar Haden. The fungicides Antracol 70 PM, Curacarb 50 WP, and Captan 50 PM were used to conform the following four treatments: T1, application of Antracol eight days prior to floral induction; T2, same as T1 but including a spray of Curacarb when plants initiate blooming; T3, same as T2 plus an extra spray of Curacarb at the end of blooming; and T4, same as T3 plus a spray of Captan during fruit growth. The treatments were applied every 15 days. Additionally, a test was carried out to determine the effect of three fungicides for the control of anthracnose on harvested fruits. The fungicides were Benlate WP, Funcloraz 40 CE and Amistar Xtra. In both assays the control consisted in a treatment without fungicide applications. In the field test, the best results were found in T3 and T4 for the percentage of isolation of Colletotrichum gloesporioides, panicles with fruits, and commercial fruit yield per tree. The second test showed that the fungicides Funcloraz and Amistar achieved the best anthracnose control on harvested fruits. Additional key words: Colletotrichum gloesporioides, fungicides, postharvest management

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Colletotrichum gloeosporioides is the causal agent of anthracnose in mango. Burkholderia cepacia XXVI, isolated from mango rhizosphere and identified by 16S rDNA sequencing as a member of B. cepacia complex, was more effective than 6 other mango rhizosphere bacteria in inhibiting the model mango pathogen, C. gloeosporioides ATCC MYA 456. Biocontrol of this pathogen was demonstrated on Petri-dishes containing PDA by > 90 % reduction of surface colonization. The nature of the biocontrol metabolite(s) was characterized via a variety of tests. The inhibition was almost exclusively due to production of agar-diffusible, not volatile, metabolite(s). The diffusible metabolite(s) underwent thermal degradation at 70 and 121 °C (1 atm). Tests for indole acetic acid production and lytic enzyme activities (cellulase, glucanase and chitinase) by B. cepacia XXVI were negative, indicating that these metabolites were not involved in the biocontrol effect. Based on halo formation and growth inhibition of the pathogen on the diagnostic medium, CAS-agar, as well as colorimetric tests we surmised that strain XXVI produced a hydroxamate siderophore involved in the biocontrol effect observed. The minimal inhibitory concentration test showed that 0.64 μg ml(-1) of siderophore (Deferoxamine mesylate salt-equivalent) was sufficient to achieve 91.1 % inhibition of the pathogen growth on Petri-dishes containing PDA. The biocontrol capacity against C. gloeosporioides ATCC MYA 456 correlated directly with the siderophore production by B. cepacia XXVI: the highest concentration of siderophore production in PDB on day 7, 1.7 μg ml(-1) (Deferoxamine mesylate salt-equivalent), promoted a pathogen growth inhibition of 94.9 %. The growth of 5 additional strains of C. gloeosporioides (isolated from mango "Ataulfo" orchards located in the municipality of Chahuites, State of Oaxaca in Mexico) was also inhibited when confronted with B. cepacia XXVI. Results indicate that B. cepacia XXVI or its siderophore have the potential to be used as a biological control agent against C. gloeosporioides; thus diminishing environmental problems caused by the current practices to control this disease.
    World Journal of Microbiology and Biotechnology (Formerly MIRCEN Journal of Applied Microbiology and Biotechnology) 08/2012; 28(8):2615-23. · 1.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Twenty isolates of Trichoderma were obtained from orchards located in three main mango-producing States in Mexico: Chiapas, Oaxaca, and Michoacan, which represent different agronomical management practices and levels of soil fertility. Phylogenetic analysis showed that Trichoderma isolates belong to the following taxa: Hypocrea lixii (10 isolates), Hypocrea jecorina (four isolates), Trichoderma asperellum (three isolates), Trichoderma spirale (two isolates), and Trichoderma brevicompactum (one isolate). The genus Hypocrea is the teleomorph (sexual) stage of the genus Trichoderma, anamorph stage. Seventeen Trichoderma isolates showed at least 67% growth inhibition against the phytopathogenic fungus Colletotrichum gloeosporioides ATCC MYA 456 and three Trichoderma isolates showed complete overgrowth of this pathogen. One member of this group, identified as T. asperellum T8a, was able to control C. gloeosporioides ATCC MYA 456 in vitro and in vivo, as well as five C. gloeosporioides isolates obtained from mango orchards from the State of Oaxaca. Assay of the lytic enzymes involved suggest that cellulases of T. asperellum T8a play a role in biological control against C. gloeosporioides ATCC MYA 456 more than chitinase or glucanase. Thus, native T. asperellum T8a associated with mango trees can be used to enhance mango production, controlling anthracnose through cellulase activity.
    Biological Control 01/2013; 64(1):37-44. · 1.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The temporal progress of anthracnose (Colletotrichum gloeosporioides) epidemics was studied in mango (Mangifera indica) orchards treated with fungicides from different chemical groups, mode of action, and application sequences in two regions of contrasting climates (sub-humid and dry tropics) in Guerrero, Mexico. Full flowering, initial setting, and 8-15mm Ø fruits were identified as critical stages for infection. Epidemics started 20-26 days after swollen buds, and maximum severity was attained at 40-42 days after the first symptoms were detected. The Weibull model described (r2>0.89) anthracnose epidemics in both floral and vegetative flushes. Active ingredients of different fungicide groups, mode of action, and residuality such as myclobutanil, azoxystrobin, cyprodinil+fludioxonil, quinoxyfen, and chlorotalonil + sulfur led to significantly low values (LSD<0.05%) in the Yf, AUDPC and b-1 parameters. The best strategy was to initiate a preventive treatment with a systemic ingredient, independently of its chemical group. Severity of the disease in floral (Fl) and vegetative flushing (Veg) in the sub-humid tropic was related with temperature >30ºC (rFl=0.79-0.86; rVeg=0.80-0.95) and relative humidity > 90% (rFl=0.66-0.86; rVeg=0.67-0.94). In both regions, conidial sporulation was related to temperature >30ºC (r=0.72-0.74), relative humidity <60% (r=0.66), severity (rFl=0.62-0.98; rVeg=0.75-0.97) and dew point <25ºC (r=0.68-0.69).
    Tropical Plant Pathology 12/2012; 37(6):375-385. · 0.51 Impact Factor