Cucurbitaceae net spot distribuition in the Santa Catarina coast and Leandria momordicae soil survival under controlled conditions

Abstract

The design of strategies to control Leandria momordicae, an inducer fungus of leaf lesions in cucurbits, is difficult due to the limited knowledge on the pathogen survival standard. With the purpose of reducing such defficiency, the fungus was evaluated for its sporulation and establishment capacities in mineral and organic soils contained into 90mm Petri dishes, sterilized and natural, moisturized up to field capacity, under temperature of 18 and 25oC, and 12 hour photoperiod. From January 2000 to June 2002 a survey was performed on fields of cucurbits
infected and non-infected by the fungus in a 150km land strip and zero to 500m altitude, from South to North and from East to West direction, respectively, starting from Florianopolis, Southern Brazil. The pathogen established in both sterilized soils, regardless of the inoculum sourse and of the temperature without sporulation. In 40% of
the samples in mineral soil not sterilizede, incubated at 18oC, the fungus estabitished without sporulation when infested by infected leaves.