Germinação e desenvolvimento de mudas do tomateiro Super Marmande submetidos à aplicação de giberelina em diferentes níveis de sombreamento

Due to the tomato growing socioeconomic importance, issues about the germination and the vegetative growth of the species are the aim of studies focusing on its improvement, seeking mostly to increase productivity. Therefore, this work aimed to evaluate the influence of the gibberellic acid and different levels of shading in the germination and initial development of tomato seedlings from the Super Marmande variety. The experimental outline adopted was in randomized blocks, arranged in factorial scheme (2x3), managing the factor A with and without the application of the hormone, Gibberellin (GA), at a concentration of 200 mg.L-1, and the factor B in three different levels of luminous intensity (full sun (0%), 70 and 90% shading). The germination and the conduction of the experiment were carried out in polyethylene trays with commercial substrate Terral®, composed of 20 plants with 10 repetitions each and the evaluations were carried out 26 days after sowing (DAS). Analysis were led on germination rate, germination speed index, germination percentage, fresh mass, fresh mass, total dry biomass, root volume, stem diameter, root length, the height of aerial part and photosynthetic pigment. Results pointed out that only the levels of shading affected the germination. The application of gibberellic acid for the Super Marmande tomato did not reveal a significant effect. The development of seedlings in the shading of 70% and 90% was better when compared to the full sun treatment.