QUALIDADE FISIOLÓGICA DE SEMENTES DE DUAS VARIEDADES DE GIRASSOL SUBMETIDAS A DIFERENTES ARRANJOS ESPACIAIS

Abstract

Sunflower (Helianthus annuus L.) cultivation has an important role in the production of food, feed and biofuels from its seeds in several tropical regions of the world. The use of spatial arrangements that promote a better physiological quality in sunflower seeds contributes to the maximization of productivity, better performance of the seedlings and their growth characteristics in the field. In this sense, the objective was to evaluate the physiological quality of seeds of sunflower (H. annuus) varieties submitted to different spatial arrangements. The experiment was conducted from August to November 2017 at the Laboratory of Seed Analysis (LAS) belonging to the Department of Plant Science and Environmental Sciences (DFCA) of the Federal University of Paraíba (UFPB), Campus II, Areia-PB. The seeds selected for the physiological quality evaluations were obtained from an experiment carried out in an area belonging to the Agricultural Sciences Center (CCA) of the UFPB, with two varieties of sunflower (black seeds and bursts) and three spacings (0.70 x 0.30 ; 0.80 x 0.30 and 0.90 x 0.30). For each treatment, 50 seeds were used, conditioned on washed sand substrates and autoclaved in the plastic trays, for determination of the tests and physiological analyzes. The statistical design was completely randomized, with treatments distributed in a 2 x 3 factorial scheme, with four replications. First counting tests, emergency speed index, emergence, green and dry matter weight, root and shoot length were determined. In the summary of the analysis of variance, significant effects of 1% of probability between varieties and 5% of probability in the interactions of the treatments were observed. In the average results of the experiment, it was verified that the seeded variety had a longer seedling length, in all the spacings tested. For the weight of green matter of seedlings, higher values were verified when the spacing of 0,90 x 0,30 m was used in the variety of bursted seeds. The use of sunflower berry seed varieties and the adoption of larger spacings favors a higher physiological quality of the seeds.