Phytophthora palmivora em solos de pomares de mamoeiro no Sul da Bahia

The root rot of papaya caused by Phytophthora palmivora has contributed for the increase of the production costs in Brazil mainly in Bahia State. Seeking to diagnose the infestation level of areas cultiveted with papaya in the Extreme South of Bahia, samplings were performed in 33 commercial orchards of papaya, cultivated with the varieties Formosa, Golden and Sunrise Solo randomly selected in the municipalities of Eunapolis, Porto Seguro, Teixeira de Freitas, Mucuri, Prado, Nova Vicosa, Alcobaca and Santa Cruz de Cabralia. The soil samples (five) were collected in a depth of 0-20 cm, composed each one for three sub-samples, randomly obtained in each area. The simple samples were homogenized, mixed to obtain a composed sample of each the five collected points of the orchard. The composed samples were placed in polyethylene bags and properly labeled. At the Laboratory of Phytophthora at CEPEC/CEPLAC, two methodologies were used to isolate the pathogen from soil samples: dilution plates with selective medium (PARPH) and soil baits with disks (1cm) of green papaya fruits. Phytophthora palmivora was detected in 31 of the 33 orchards evaluated. There were no significant differences for the pathogen incidence in relation to the papaya varieties planted in the orchards. Phytophyhora. palmivora was detected in the orchads of all eight municipalities, attesting its wide distribution in southern Bahia State