Progress 09/01/07 to 08/31/10
Outputs
OUTPUTS: Fungal diseases and insect pests of mango inflorescences were evaluated during two blooming seasons at the Agricultural Experiment Station of the UPR. Inflorescences were collected from four mango cultivars at seven flowering stages. Necrosis, powdery mildew and tip blight were the predominant symptoms observed in the field. Malformation was not observed on inflorescences. Necrosis was observed at the very early developmental stages whereas powdery mildew was observed from green colored to full bloom stage. Disease severity was higher in full bloom stage. Thirty six fungal species were identified from mango inflorescences at different developmental stages. Among them Albonectria rigidiuscula (= Fusarium decemcellulare), Alternaria alternata, A. infectoria, A. tenuissima, Bipolaris spp., Botryosphaeria dothidea, B. parva, B. rhodina (syn. Lasiodiplodia theobromae), B. ribis, Cladosporium cladosporioides, Cochiliobolus lunatus, Corynespora casiicola, Curvularia pseudorobusta, Cylindrocladium pacificum, Diaporthe sp., Fusarium chlamydosporum, F. equiseti, F. moniliformis, F. oxysporum, F. solani, Gelasinospora sp., Glomerella cingulata (= Colletotrichum gloeosporioides), Humicola sp., Leptosphaerulina chartarum, Neofusiccocum mangiferae, Nigrospora oryzae, Oidium mangiferae, Periconia macrospinosa, Pestalotiopsis mangiferae, Phoma exigua, P. sorghina, Phomopsis longicolla, Phomopsis sp., Pyrenochaeta romeroi, Thielaviopsis sp. and member of the order Xylariales. Under field conditions, twelve fungal species were evaluated during pathogenicity tests on mango inflorescences. B. rhodina and N. mangiferae caused tip blight. A. rigidiuscula caused vascular necrosis and flower abortion. Eliptical lesions and cankers were caused by Alternaria spp. and P. sorghina. G. cingulata, Phomopsis spp., B. dothidea, B. ribis and B. parva, caused localized necrosis. Differences were observed among fungal isolates and mango cultivar evaluated. Insects belonging to the Order Diptera prevailed during the surveys (70%) followed by the Order Thysanoptera (16%), Hymenoptera (9%), Homoptera (4%) and others such as Colepotera, Lepidoptera and Neuroptera (1%). Gephyraulus mangiferae caused 50% of inflorescences damage. Insects belonging to the Order Thysanoptera identified were: Rhamphothrips sp., Haplothrips gowdeii and Frankliniella bruneri. Rhamphothrips sp. was the most abundant species. Three Lepidotera specimens were collected: Phidotricha erigens (Fam. Pyralidae) and two unknown specimens belonging to the Geometrida and Tortricidae families. Apanteles sp., Pholeteson sp. and Phanerotoma sp. (Fam. Braconidae) were found parasitic to Lepidopteran. Interaction between thrips and fungal pathogens were evaluated under field conditions. The highest disease severity was observed in inflorescences inoculated with fungi with artificial wounds and inoculation of fungi with thrips infestation. Inflorescences treated with thrips and B. ribis, B. dothidea, B. rhodina, N. mangiferae, P. sorghina and P. longicolla caused up to 100% disease severity. Management strategies in the field should emphasize thrips and disease control to reduce flower and eventually fruit damage. PARTICIPANTS: Professional development: Oral and poster presentations were made by undergraduate and graduate students at the Annual Meeting of the Joint American Phytopathological Society-Caribbean Division (APS-CD) with the International Integrated Pest Management Meeting held at Nicaragua from March 19 to 22, 2010 on project advances. Project leader participated in Symposium of Molecular techniques to diagnose phytopathogenic fungi of tropical crops presented at the Annual meeting of the Joint APS-CD with the IPM Meeting held at Nicaragua. Project advances were presented to a Central American audience. Parter organizations: Arturo Roque Fellowship (Agricultural Research Station-UPR) and PRLS-AMP (NSF grant HRD 0601843) sponsored undergraduate student (Laura Berrios) research collaboration in the project. TARGET AUDIENCES: Change of knowledge: Five species of necrotrophs belonging to the Botryosphaeriacea family: Botryosphaeria dothidea, B. parva, B. rhodina (syn. Lasiodiplodia theobromae), B. ribis and Neofusiccocum mangiferae were identified using molecular techniques and their implications as fungal pathogens were addressed. Gephyraulus mangiferae (Diptera: Cecidomyiidae) was reported causing 50% of inflorescences damage. Insects belonging to the Order Thysanoptera were identified (Haplothrips gowdeii, Frankliniella bruneri and Rhamphothrips sp.). Three Lepidotera specimens were collected: Phidotricha erigens (Fam. Pyralidae) and two unknown specimens belonging to the Geometrida and Tortricidae families. Apanteles sp., Pholeteson sp. and Phanerotoma sp. (Fam. Braconidae) were found parasitic to Lepidopteran. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A diverse group of fungi and insect pest were identified from mango inflorescences in the current study. Five species belonging to the Botryosphaeriacea family were identified using molecular techniques and their implications as fungal pathogens were addressed. Combination of DNA analysis with morphological data resulted in a more accurate diagnose of fungal species. Insects belonging to diverse Orders were identified. Diptera prevailed during the surveys (70%). Gephyraulus mangiferae was reported causing 50% of inflorescences damage. Insects belonging to the Order Thysanoptera identified were: Haplothrips gowdeii, Frankliniella bruneri and Rhamphothrips sp., Three Lepidotera specimens were collected: Phidotricha erigens (Fam. Pyralidae) and two unknown specimens belonging to the Geometrida and Tortricidae families. Apanteles sp., Pholeteson sp. and Phanerotoma sp. (Fam. Braconidae) were found parasitic to Lepidopteran. Correct identification of mango inflorescences fungal pathogens and pests is important when quarantine regulations are applied. In addition, this information will help us to develop better management strategies of the different fungal and pests species in mango orchards.
Publications
- Berrios, L. and L.I. Rivera-Vargas. 2010. Phytopathogenic fungi of immature mango (Mangifera indica L.) fruits. Phytopathology (Abstract). Cabrera Asencio, I., L.I. Rivera-Vargas and A.L. Velez. 2009. First report of mango blossom midge Gephyraulus mangiferae (Felt) (Diptera: Cecidomyiidae) in Puerto Rico. J. Agric. Univ. P.R. 93(3-4):255-257. Perez, M. and L.I. Rivera-Vargas. 2007. Mycoflora associated with mango inflorescences at the Agricultural Experiment Station germplasm collection in Juana Diaz, Puerto Rico. IX Mycology Symposium, Catholic University-Ponce Campus. Ponce, P.R. (Abstract).
- Perez, M. and L.I. Rivera-Vargas. 2008. Symptomatology of fungal diseases in mango inflorescences of commercial cultivars. Proc. of the Puerto Rican Society of Agricultural Sciences. Aguadilla, P.R. (Abstract).
- Perez, M. 2010 Etiology of mango (Mangifera indica L.) inflorescence's diseases. M.S. Thesis. Dept. Crops and Agroenvironmental Sciences. UPR-Mayaguez Campus. 88 pp.
- Zayas Garcia, E.J. 2011. Identification and population dynamics of thrips occurring in mango (Mangifera indica L.) inflorescences and their relation to phytopathogenic fungi. M.S. Thesis. Dept. Crops and Agroenvironmental Sciences. UPR-Mayaguez Campus. (in progress).
- Zayas Garcia, E.J., I. Cabrera-Asencio and L.I. Rivera-Vargas. 2010. Interactions between thrips and plant pathogenic fungi in mango inflorescences. Phytopathology. (Abstract).
- Zayas Garcia, E.J., I. Cabrera-Asencio and L.I. Rivera-Vargas. 2009. Identification of thrips from mango (Mangifera indica L.) inflorescences. Proc. of the Annual Meeting of the Puerto Rican Society of Agricultural Sciences (SOPCA), Hato Rey, P.R. (Abstract).
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Fungal diseases and insect pests of mango inflorescences were evaluated during two blooming seasons: November 2007 to April 2008 and January to February 2009 at the Agricultural Experiment Station of the UPR located at Juana Diaz, Puerto Rico. Necrosis, powdery mildew and tip blight were the predominant symptoms observed in the field during the surveys. Malformation of mango inflorescences was never observed. Necrosis was observed at the very early developmental stages whereas powdery mildew was observed from green colored stage to full bloom. A diverse group of fungi were morphologically and molecularly characterized from mango inflorescences of different developmental stages. Among them were Albonectria rigidiuscula, Alternaria spp., Botryosphaeria spp., Cladosporium Cochiliobolus lunatus, Colletotrichum gloeosporioides, Corynespora sp., Curvularia spp., Fusarium spp., Humicola sp., Lasiodiplodia sp., Leptosphaerulina sp., Neofusiccocum mangiferae, Nigrospora oryzae, Oidium mangiferae, Periconia sp., Pestalotipsis mangiferae, Phoma exigua, P. sorghina, sp., Phomopsis spp. and Thielaviopsis sp. Experiments conducted to chemically induce mango inflorescence in six-month-old seedlings under greenhouse conditions to be used for pathogenicity tests were ineffective. Under field conditions, eleven fungal species were selected and evaluated for pathogenicity tests which were conducted in December 2009. Inflorescences from red colored to full bloom stages were superficially sterilized and inoculated with fungal conidial suspension (105 conidia/ml) or mycelium of mango cultivars Haden and Parvin. Albonectria rigidiuscula and Botryosphaeria rhodina were virulent on mango inflorescences causing 100% severity in cultivar Haden, eight days after inoculation as compared with 36% severity in cultivar Parvin. Phomopsis longicolla, B. ribis and Fusarium moniliformis were virulent on mango inflorescences of cultivar Parvin with 100% severity, five to eight days after inoculation. Alternaria infectoria, A. alternata, Botryosphaeria ribis, B. parva, Fusarium moniliformis and Leptosphaerulina sp. were less virulent with severity ranging form 0 to 25%. Haplothrips gowdeii, Frankliniella bruneri and Rhamphothrips sp. belonging to the Order Thysanoptera were collected from mango inflorescences during a survey conducted from January to February 2009. Rhamphothrips sp. was the most abundant species. Thrips prevailed in full bloom stage. The highest peak of thrips population occurred 16 January 2009, with 2,825 specimens collected, whereas the lowest occurred on 24 February 2009 with only 39 specimens collected. Eighty-four percent of the specimens collected were females. Experiments are in progress to evaluate the pathogenicity of a diverse group of fungi and their interaction with thrips on mango inflorescences under field conditions. PARTICIPANTS: Rivera Vargas, L.I. : PI/Plant Pathologist Cabrera, I.: Co-PI/Entomologist Perez Cuevas, M. - graduate student, working in the identification of fungal isolates obtained from mango inflorescences Zayas E. - graduate student, will work in the identification of insects associated with mango inflorescence TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
A diverse group of fungi and insect pests have been identified from mango inflorescences in the current study. As an example, four Botryosphaeria spp. were identified. Misidentifications of this group of fungi from mango have been confusing when based solely on morphological criteria. The combination of DNA analysis with morphological data resulted in a more accurate information of fungal species and their pathogenicity on mango inflorescences in Puerto Rico. Correct identification of fungal pathogens and pests of mango inflorescences is important when quarantine regulations are applied. In addition, this information will help us to develop better management strategies of the different fungal and pest species in mango orchards.
Publications
- Perez Cuevas, M. and L.I. Rivera Vargas. 2009. Morphological and molecular characterization of fungi in mango inflorescences of commercial cultivars. Proceedings of the Caribbean Food Crop Society. Federation of St. Kitts and Nevis (Abstract).
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Four mango cultivars (i.e., Haden, Irwin, Keitt and Parvin), selected on the basis of commercial value and genetic background, were evaluated for fungal diseases and insect pests during blooming season from August 2007 to May 2008. Eleven fungal genera were identified from symptomatic and asymptomatic mango inflorescences: Alternaria spp., Bipolaris sp., Colletotrichum gloeosporioides, C. acutatum, Curvularia spp., Fusarium spp., Nigrospora sp., Oidium mangiferae, Pestalotipsis mangiferae, Phoma sp., Phomopsis spp. and Thielaviopsis sp. According to Schoeman's classification of mango inflorescences on the basis of developmental stages, the majority of the fungi were associated with the last developmental stage: full bloom (41%). No fungi were isolated from the earliest developmental stage, bud swell to bud break. Powdery mildew (O. mangiferae) and necrosis were the most common symptoms, occurring in 69 and 54.4% of symptomatic inflorescences. Powdery mildew was observed affecting the last two developmental stages of the inflorescences: red-open and full bloom. Inflorescence malformation was not observed in the field. Flower, panicle and small fruit necrosis was associated with Alternaria, Colletotrichum spp. Curvularia sp., Fusarium sp., and Phoma sp. Six fungal genera were isolated from asymptomatic tissues: Alternaria spp., Colletotrichum spp., Curvularia spp., Fusarium spp. and Nigrospora sp. and Phomopsis sp. Forty-two percent of the fungi were associated with mango cultivar Irwin. Experiments are in progress to chemically induce mango inflorescence in six-month-old seedlings under greenhouse conditions to be used for pathogenicity tests. Insects belonging to the orders Thysanoptera, Lepidoptera, and Diptera were surveyed from mango inflorescences. Frankliniella bruneri Watson, F. occidentalis and Rhamphothrips sp. (Order Thysanoptera) were identified from mango cultivar Irwin. Frankliniella occidentalis was found associated with Haden inflorescences. Two different lepidopteran larvae associated with mango blossom drop were collected and were sent to the Systematic Entomology Lab at Beltsville, Maryland, for identification. In addition, members of the Order Tubullifera were found to be associated with mango cultivars Keitt and Haden. A new report for Puerto Rico of mango blossom midge, Gephyraulus mangiferae Felt., a dipteran from the Cecidomyiidae family, was identified and corroborated by the Systematic Entomology Lab at Beltsville, Maryland. This dipteran is considered a pest of mango inflorescences in India. Experiments are in progress to determine G. mangiferae percentage of damage to inflorescences. PARTICIPANTS: Rivera Vargas, L.I. : PI/Plant Pathologist Cabrera, I.: Co-PI/Entomologist Perez Cuevas, M. - graduate student, working in the identification of fungal isolates obtained from mango inflorescence Zayas, E. - graduate student, will work in the identification of insects associated with mango inflorescence TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Despite the relative worldwide economic importance of mango and particularly in Puerto Rico, few studies have been conducted on pests and fungal pathogen populations associated with mango inflorescences. Thus, correct identification of pest and fungal pathogens is crucial to their control, to endorsement of quarantine regulations, and to the understanding of the dynamics of the different fungal and insect pest species involved in the orchards.
Publications
- Perez Cuevas, M. and L.I. Rivera Vargas. 2008. Symptoms associated with fungal diseases in mango inflorescences of commercial cultivars. Proceedings of the Puerto Rican Agricultural Sciences Society. Aguadilla, P.R. (Abstract).
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