Promotores de crescimento na produção de mudas de alface com e sem fertirrigação

Abstract

Lettuce is one of the most cultivated and consumed vegetables in Brazil and in the world. And the success of your crop depends on the use of seedlings of great quality, and the production of seedlings is one of the most important steps in horticulture. In addition, it is also important to seek agronomic strategies that can contribute to a more sustainable agriculture, such as the use of microorganisms that promote plant growth in the seedling production stage. Thus, the objective of the present work was to eval- uate the effect of Trichoderma asperellum, Bacillus amyloliquefaciens and Azospirillum brasiliense as growth promoters on lettuce seedlings grown under two irrigation con- ditions (with and without fertigation). The experiment was conducted in a greenhouse, in the experimental area of the Fronteira Sul Federal University, Cerro Largo campus. The experimental design was the completely randomized design (DIC), in a 4 x 2 fac- torial scheme with three replications, totaling 24 UEs, where a factor with two levels: with fertigation and without fertigation. And another factor with four levels: control (no application), and growth promoters: Azospirillum brasilense (5X10⁸ cells per mL of product); Bacillus amyloliquefaciens (4 x 10⁹ CFU / ml) and Trichoderma asperellum (1x10¹ ° viable conidia per gram of product). The microorganisms were applied to the substrate, and 30 days after sowing as evaluated seedlings and the data obtained submitted to the Tukey test at 5% probability. The application of Trichoderma asperel- lum to the substrate showed capacity to promote plant growth, obtaining results of the same significance between seedlings with and without fertigation for the parameter of shoot height and fresh shoot mass. The bacteria Bacillus amyloli-quefaciens and Azospirillum brasiliense, when applied to the substrate, did not demonstrate capacity to promote plant growth of lettuce seedlings, demonstrating lower results among seed- lings without fertigation for the dry mass parameter of shoot.