Restrição hídrica em teste de sanidade e microbiolização com Trichoderma sp. em sementes de níger (Guizotia abyssinica)

Abstract

Niger (Guizotia abyssinica) is an oilseed plant, originally from Ethiopia, and its expansion in Brazil demand good quality seeds physical, physiological and sanitary. In seed health testing is common to use water restriction to inhibit germination and contamination between seeds with the external environment, it is imperative that these treatments do not interfere with the growth of target organisms evaluation. The use of the technique of seeds microbiolization with some Trichoderma species has been successful in controlling fungi and their effectiveness is unknown in Niger. Aiming to contribute information to meet these demands, there were two laboratory experiments. The first was to evaluate the efficiency of water restriction on the inhibition of germination of seeds for adaptation of the method of incubation on filter paper in sanity. The second assessed the efficiency of seed microbiolization with Trichoderma sp. For the analysis of sanity, seeds were placed in Petri dishes on three sheets of filter paper moistened with solutions of KCl, NaCl and mannitol at the potentials of -0.6, -0.8, -1.0 and -1 2 MPa and two additional treatments: incubation method on filter paper and the method of freezing. To Microbiolization, niger seeds were immersed in a suspension of 106 conidia / ml of Trichoderma sp., Followed by health analysis and physiological seed quality. The method of incubation on filter paper modified with water restriction reduced the germination of seeds of the niger and not changing significantly the incidence of fungi in sanity. The KCl in the potential of -1.2 MPa was the solute had the highest percentages of reduction in germination and shorter length of primary root. The microbiolization reduced the incidence of fungi associated with seeds and plants produced greater height and dry matter.