Utilização de silício na germinação de sementes e crescimento de plântulas de milho submetidas a deficiência hídrica

Abstract

Water deficiency compromises adequate germination and, consequently, plant growth and development. Studies attest how silicon is able to mitigate the effect of water deficiency in plants. The objective was to evaluate the effect of silicon on the germination andgrowth of corn seedlings submitted to water deficiency. The experimental design wascompletely randomized (DIC) (factorial 3x4), with three concentrations of calcium silicate(0.0; 1.0 and 2.0 mM) and 4 water deficiency levels simulated by different osmotic potentials (0.0; -0.3; -0.6; -0.9 MPa) generated by PEG-6000. The germination percentage, the germination speed index, the average germination time, the percentage of non-germinated and abnormal germinated, the length and dry matter of the aerial part, root and total seedlings were evaluated. The water deficiency negatively affected the germination test, reduced the speed and increased the average time, since the seeds without deficiency germinated normally while those submitted to deficiency did not have normal germination. It also reduced the production of shoot, root and total dry matter by approximately 93%, 81% and 87%, respectively of seedlings subjected to deficiency compared to seedlings without deficiency.As for the length of the aerial part, root and total, there was a reduction of approximately 87%, 70% and 77%, respectively among seedlings submitted to deficiency in comparison to seedlings without deficiency.The use of calcium silicate in corn seeds did not alleviate the stress caused by water deficiency in terms of germination parameters and in terms of growth and dry mass production parameters.