Avaliação do potencial de uso da restrição hídrica em teste de sanidade de sementes de trigo visando à detecção de fungos

Abstract

The objective of this study was to evaluate the use of the water restriction technique as an alternative to deep freezing for inhibiting wheat seed germination during blotter test incubation. The two techniques were compared using sixty seed samples collected in different areas of Minas Gerais state and other regions of Brazil. The water restriction established was determined by using manitol, at a potential of -1.10 MPa, based on the results of preliminary essays. The mean incidence of B. sorokiniana was not affected by any of the two techniques. Values for the incidence of Pyricularia grisea, Aspergillus ochraceus, Cladosporium cladosporioides and Epicoccum purpuracens were higher when water restriction was used. On the other hand, values for the incidence of Alternaria alternata, Drechslera tritici-repentis and Fusarium graminearum were lower with water restriction. Elongation of the seed radicle can be tolerated to a certain degree during blotter test incubation and the water restriction technique is a potential alternative of the freezing technique for detecting most of the fungi associated with wheat seeds.