Abstract Background Phytosociological surveys of weeds in agricultural regions, such as the coffee growing Cerrado Mineiro Denomination, are essential for understanding the predominant species in a cultivation area. Objective This study aimed to determine the predominant weed species in coffee crops in Cerrado Mineiro through phytosociological surveys during two periods of the year. Methods 26 coffee farms in 12 municipalities within the Cerrado Mineiro Denomination of Origin of were visited. The inventory square method was used for the phytosociological surveys. In each area, 40 m2 was evaluated and divided into two study periods (summer and winter). Calculations of the variables were performed using the following data: frequency, density, abundance, importance value index, similarity coefficient, rarefaction curve, Shannon index, and hierarchical grouping analysis using Jaccard’s similarity. Results In the summer (rainy period), 54 species from 16 families were found, with Poaceae, Asteraceae, and Amaranthaceae predominating. In winter (dry season), 56 species from 16 families were found, predominantly Asteraceae, Poaceae, and Brassicaceae. There was a predominance of 17 and 16 species, with similarity levels (Jaccard) of 45.58% and 40.78% for summer and winter, respectively. Conclusions The weed community in the Cerrado Mineiro coffee plantation is dominated by two main families, Poacaeae and Asteraceae, with Eleusine indica (summer) and Conyza spp. (winter) being the species with the highest importance values.

O uso do herbicida glifosato afeta o balanço nutricional, a nodulação, fatores bioquímicos, fisiológicos e consequentemente podem afetar os componentes de produção da cultura da soja RR®. Foi objetivo neste trabalho, avaliar o efeito de doses de glifosato sobre a fitotoxidade e os caracteres agronômicos cultivares de soja RR®. O delineamento experimental utilizado foi em blocos casualizados, dispostos em esquema fatorial 3 x 6, com três repetições. Os tratamentos foram constituídos por três cultivares de soja RR® (CD 250, TMG 1174 e V-MAX) e seis doses do herbicida glifosato (0, 960, 1920, 2880, 3840, 4800 g e.a. ha-1), utilizou-se o produto comercial Roundup Ready®. Foram avaliadas: matéria seca aérea, fitotoxidade, altura das plantas, inserção da primeira vagem, massa de mil grãos e produtividade de grãos. A aplicação de doses crescentes de glifosato até 4800 g e.a. ha-1 ocasionou fitotoxidade em plantas de soja, todavia, não causaram injúrias suficientes a ponto de reduzir os caracteres agronômicos da soja. A maior produtividade dos grãos, foi verificado para a cultivar TMG 1174 RR em Lavras e para a cultivar V-MAX RR em Patos de Minas.

The use of glyphosate herbicide affects nutritional balance, nodulation, biochemical, physiological factors and consequently can affect the components of production of the RR®soybean crop. The objective of this work was to evaluate the effect of glifosato doses on the phytotoxicity and agronomic traits of RR® soybean cultivars. The experimental design was in randomized blocks, arranged in a 3 x 6 factorial scheme, with three replications. The treatments consisted of three RR® soybean cultivars (CD 250, TMG 1174 and V-MAX) and six doses of the herbicide glifosato (0, 960, 1920, 2880, 3840, 4800 g e.a. ha-1), were used Roundup Ready® commercial product. They were evaluated: aerial dry matter, phytotoxicity, plant height, first pod insertion, one thousand grain mass and grain yield. The application of increasing doses of glifosato up to 4800 g e.a. ha-1 caused phytotoxicity in soybean plants, however, they did not cause enough damage to reduce the agronomic characteristics of soybean. The highest productivity of the grains was verified for cultivar TMG 1174 RR in Lavras and for cultivar V-MAX RR in Patos de Minas.