Avaliação de parâmetros de crescimento da alface (lactuca sativa) inoculada com Azospirillum brasiliense estirpe sp. 245.

Abstract

The cultivation of lettuce (lactuca sativa) is very common throughout the country, being an important source of income, mainly in family agriculture. The vegetable industry in Sergipe in recent years has been increasing production, contributing to the balance of supply and demand in the domestic market, with Itabaiana being one of the main producing municipalities. This municipality is inserted in the Central Agreste Territory of the State of Sergipe, where it exerts a strong influence in the neighboring municipalities. However, agricultural practices such as intensive cultivation of the soil, monoculture and frequent use of pesticides still predominate in the municipality of Itabaiana and region, often disregarding socioenvironmental factors. The objective of this work was to evaluate lettuce growth parameters from the inoculation or non-inoculation of the Azospirillum brasiliense strain sp. 245 in a commercial area of a farmer of the Agreste-ASPOAGRE Association of Organic Producers. The parameters evaluated were: root volume (VR), shoot diameter (DPA), total fresh matter (MFT), total dry matter (MST), root length (CR), nitrogen content in shoot and shoot height (APA). Two experiments were carried out between October 2018 and February 2019. Experiment 1 started on 29/10/2018 and ended on 12/01/2019. In the first stage, growth parameters of curly lettuce were evaluated under field conditions. The experimental design was a randomized block design with four treatments and four replications, according to a factorial model, 2 x 2, that is, with two different substrates (one commercial and the other prepared by the producer) and the presence or absence of the inoculant based on the sp. strain 245 of A. brasiliense. Each plot was 5.2 m long by 0.7 m wide, and the plots consisted of 1.3 m long, 0.7 m wide, where it allowed the planting of 10 seedlings in each plot and 40 per plot, and the inoculant based on the Azospirillum brasiliense strain sp. 245had a positive influence on practically all parameters analyzed. Experiment 2 began on 01/14/2019 and was terminated on 02/02/2019. The seedlings were produced using a 200-cell plastic tray with two substrate types: commercial organic substrate (SOC) in the first half of the tray and organic substrate produced in the other half (SOP). The experimental design was a completely randomized (DIC), with eight treatments, according to a factorial model, 2 x 2 x 2, that is, with two different substrates, the presence or absence of the inoculant with the Azospirillum brasiliense strain sp. 245 and the two groups of lettuce (crisp and American). In the second part, some parameters of the seedling stage were evaluated, observing that the effect of all the treatments used on the MFT variable is similar. However in the APA variable there was a significant effect of the treatments where the inoculation was based on the Azospirillum brasiliense strain sp. 245.