Semente de Urochloa ruziziensis tratada com diferentes fungicidas e doses

Abstract

The initial protection of plants through the use of fungicides has been efficient for a good sanitary management. However, some molecules used in seed treatment have a varied physiological effect on germination and initial development. The present work aimed to test different fungicides and doses in the treatment of two lots of Urochloa ruziziensis seeds, with high and low cultural value, on the health and physiological effects caused on the seed. The experiment was developed at the Phytopathology Laboratory of the Federal University of Mato Grosso, Campus Cuiabá, and conducted in two tests, each evaluated a seed lot: U. ruziziensis 48% VC (Test I). U. ruziziensis 72% VC (Assay II). Both experiments were carried out in a completely randomized design, with the treatments arranged in a double factorial scheme (3x3 + 1), with three active ingredients (Carbendazim; Carbendazim + Tiram; Carboxine + Tiram), three doses (50%; 100% and 150 % in relation to the recommendation of the manufacturer of each product) and a control treatment, with four repetitions. After the application of the products and doses, parameters related to physical purity, mass of a thousand seeds, moisture content and the effect of the best combination between product and dose in relation to the health and physiological quality of the seeds compared to the control treatment were measured. The collected data were collected through analysis of variance and regression at 5% probability. For seeds of U. ruziziensis 48% and 72% VC, treatment with Carboxine + Tiram or Carbendazim + Tiram is recommended for the control of pathogens associated with the seeds. The ingredient ingredient Carbendazim promoted better control over the increase of fungi associated with seeds of low and high cultural value. The length of the aerial part and root, dry mass of seedlings of U. ruziziensis 48% VC is increased when the active ingredient Carboxina + Tiram is used with 50% of the recommended dose. Seed treatment with Carbendazim reduces germination, shoot length, root and dry mass of seedlings of U. ruziziensis with low cultural value. Despite less control over the incidence of fungi, a dose of 50% of the fungicide Carbendazim is effective in the treatment of seeds of U. ruziziensis 72% VC, contributing to a lower percentage of abnormal seedlings, greater root length and percentage of germination at the first count do aging test. The ingredient ingredient Carboxina + Tiram is not indicated for use in U. ruziziensis seeds of high cultural value, as it has a negative effect on root length and increased abnormality in the germination test.