LEVANTAMENTO FITOSSOCIOLOGICO DE PLANTAS DANINHAS

Abstract

The experiment was installed totaling 40 plots, each experimental plot with a size of 2m x 0.8m totaling 1.6m, consisting of five rows of 2m long with 0,20m spaced border between lines, occupying an area of 64m. The first survey was performed at V approximately 25 days after emergence of the crop (25 DAE), while the second was performed at V at 47 days after emergence approximately (47 DAE). In the analyzed parameters the following formulas were used: Frequency (F) = square number where the species was found ÷ total square number; Relative Frequency (Fr) = species frequency x 100 ÷ total species frequency; Density (D) = total number of individuals of the species ÷ total square number; Relative Density (Dr) = species density x 100 ÷ total species density; Abundance (A) = total number of individuals of the species ÷ total number of squares where the species was found; Relative abundance (Ar) = species abundance x 100 total species abundance and Relative importance index (Ir) = relative frequency + relative density + relative abundance. The weeds were identified and quantified by the inventory square method, where a 1.0 x 1.0m square was casually released. A total of 19 species were identified, grouped in 17 families. In the first survey it was noticeable the predominance among the families Amaranthaceae, Euphorbiaceae and Grasses, 2 species each, making a total of 13.33%, and the others accounted for 1 species each, reaching 6.66%. In the second survey only the families Amaranthaceae and Gramineae remained with 2 species each, reaching the amount of 11.11%, and the remainder accounted for only 1 species, totaling 5.55%. Being evidenced the numerical superiority of the dicotyledonous species, both in the first and in the second survey both with 66.66%.