BERNARDO, E. R. A.

BETTIOL, W.

English

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Control of citrus black spot (Guignardia citricarpa) by biological control agents and other alternative products.

P71 CONTROL OF CITRUS BLACK SPOT {GUIGNARDIA CITRIC ARP A) BY BIOLOGICAL CONTROL AGENTS AND OTHER ALTERNATIVE PRODUCTSWagner Bettiol, Eduardo R. A. BernardoLaboratory o f  Environmental Microbiology, Embrápa Environment, CP 69, 13820-000 Jaguariúna, São Paulo, Brazil, e-mail: bettiol@cnpma.embrapa.br.Citrus black spot (CBS) has been responsible for substantial damage in citrus, in different countries. In Brazil, the disease occurs in several municipalities in the State of São Paulo, in an area that is highly representative of the state’s citriculture. Black spot control basically relies on the use of protective or systemic fungicides, applied at 28-day intervals. The objective of this work was to evaluate the effects of biocontrol agents (Bacillus snbtilis and Trichoderma sp.) and other alternative products (cow milk and biofertilizer) to control CBS in organic and conventional systems.In the first experiment, the following treatments were done: B. subtilis (107 and 108 UFC/ml); autoclaved Milhocina (0.5%) + Molasses (0.5%); Trichodemia sp. (106 conidia/ml); cow milk (5%) and Microgeo® (commercial biofertilizer currently used by citrus organic growers). All treatments, except Microgeo®, were sprayed at scheduled intervals (0, 28, 56, 84, 112, 140, and 168 days) from December 8, 2004 (bloom period) to August 28, 2005 (fruit harvest). The Microgeo® treatment was sprayed along all year at a monthly interval. The experiment was conducted in a completely randomized blocks design with 5 treatments and 15 replication plants (‘Pera’). The severity of the disease on 50 fruits at harvest stage collected randomly from each replication plant were evaluated by means o f a six-category scale, where 1=0.5%, and 6=49% of fruit area with lesions. The percentage of fruits classified at class 1, 2 and 3 to 6 were calculated. The milk and B. subtilis (108) treatments did not differed significantly from each other and presented the higher percentage of fruits classified at class 1 (26.3% and 19.4%, respectively) and the lower percentage of fruits at class 3 to 6 (29.9% and 35.6%, respectively). The milk and B. subtilis treatments were significantly superior to Microgel® treatment (10.9% e 50.8%, respectively for fruits at class 1, 2 and 3 to 6).In the second experiment, in a ‘Valência’, on conventional system orchard, different doses (0, 2.5, 5, 7.5, and 10% v/v) of a biofertilizer (produced by aerobic fermentation of a mixture of molasses, compost cattle manure, earthworm humus, yeast and water) were sprayed at the same dates as the first experiment and compared with a standard fungicide treatment. The % of fruits classified as 1 and 2 were 4.4, 8.0, 5.8, 6.6, 4.9 and 12.8, respectively for the treatments 0, 2.5, 5.0, 7.5 and 10% of biofertilizer and fungicide. The percentage of fruits classified as 5 and 6, for the same treatments were 38.4, 29.5, 27.8, 28.4, 28.0, and 19.4. The results show the potential of bio fertilizer, milk and B. subtilis as an alternative for citrus black spot control, especially in organic agriculture.139International Organisation for Biological and Integrated Control of Noxious Animals and Plants (IOBC)West Paiaearctic Reg/on a! Section (WPRS)Organisation Internationa le de Lutte B io log ique e t Intégrée contre les An im aux e t les Plantes Nuisib les (01LB)Section Régionale Ouest Pe/èarctique (SROP)Bettiol Wagner Embrapa Environment Rod. SP 340, Km 127,5, Caixa Postal 690 Jaguariüna BrazilSpa, September 10, 2006Proof of participation at the lOBC/wprs Workshop “Fundamental and practical approaches to increase biocontrol efficacy”Spa, Belgium, September 6-10, 2006To whom it may concernThis is to certify that Bettiol Wagner actively participated at the IOBC workshop, held on September 6-10, 2006 in Spa, Belgium.At the workshop, Bettiol Wagner presented a poster/©#a+ presentation with the following title: Control of Citrus black spot (Guignardia citricarpa) by biological control agents and other alternative productsIn view of his/her active contribution to the programme, his/her presence at the IOBC workshop was highly appreciated.Yours sincerely,Prof. Monica HöfteLocal organizer IOBC workshop

Control of citrus black spot (Guignardia Citricarpa) by biological control agents and other alternative products.

http://www.alice.cnptia.embrapa.br/bitstream/doc/1027809/1/2006RA062.pdf

Control of citrus black spot (Guignardia Citricarpa) by biological control agents and other alternative products.

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