SURVIVAL OF Fusarium subglutinans f. spp. ananas IN SOIL

Abstract

The pineapple (Ananas comosus) is one of the most important crops in the state of Pará, this being the third largest producer in the country. The increase in planted area in the state, coupled with the importation of plants not inspected, favored the spread of the fungus Fusarium subglutinans f. spp. ananas, which causes the disease called fusarium or gummosis. 0 6 aim of this study to evaluate the survival period of F subglutinans f. spp. pineapple in natural soils from different sources. The experimental design was completely randomized factorial of obeying the 3x7x10 (three provenances of soils, seven incubation periods and ten repetitions), the origins of the soils are: (1)
Salvaterra, Marajó, For (Yellow Latosso medium texture), (2) the Guama River Estuary within UFRA (Gley Little distrophic Hilmico), (3) area of land within the UFRA (Latosso Yellow Alico medium texture), with incubation periods being 0, 5, 10, 15, 20, 25 and 30 days with 10 replicates for analysis, and the analysis made in each incubation period with a repetition consists of two polyethylene containers 200 ml capacity containing 50 g of soil each. For this soil infestation a concentration of 105 conidios.m1-1 suspension was used, adding to the suspension 5M1. Assessments of pathogen survival were made every five days amid PCNB, for thirty days, and prepared two plates per replicate. The pathogen was reduced to negligible levels within thirty days their survival in natural soils. The residue of pineapple, contained in soils cultivated with culture, did not influence the survival of the pathogen after thirty days. In sterilized soil, F subglutinans f. spp. dwarf survived the saprophytic way for long periods, the type of organic matter in the soil from Salvaterra did not influence survival of F subglutinans f. spp. dwarf for soil sterilization vertical autoclave was used.