Weed Interference in the Morphophysiological and Nutritional Characteristics of Erva-Mate (<i>Ilex paraguariensis</i>)

Abstract

The erva-mate (Ilex paraguariensis) represents an alternative crop for agricultural exploitation in South Brazilian farms with potential to export the harvested product. However, there is scarce information about the interference caused by weeds on this crop. The objective of this work was to evaluate the interference of weed species on the morphophysiological and nutritional characteristics of erva-mate. The experiment was installed in greenhouse at the Federal University of Fronteira Sul (UFFS), Campus Erechim/RS, Brazil, in randomized blocks design, arranged in a 4 × 6 factorial scheme, with four replications. In factor A, weed species (Urochloa plantaginea-Alexandergrass, Bidens pilosa-Hairy beggarticks, Ipomoea indivisa-Morning glory and Conyza bonariensis-Hairy fleabane) were allocated, and in B the populations of these species competing with the erva-mate (0, 1, 2, 3, 4 and 5 plants per pot) were considered. The variables evaluated in erva-mate were sub-stomatal CO 2 concentration, photosynthetic rate, CO 2 consumed, stomatal conductance, transpiration rate, water use efficiency, height, stem diameter, leaf area and shoot dry mass. Concentrations of nitrogen (N), phosphorus (P), calcium (Ca) and magnesium (Mg) were also evaluated. Overall, all weed species and densities among the tested ones harmed the development of erva-mate plants, which was considered as low competitive with weeds.

Growth and development of yerba mate seedlings associated with different winter cover species

“…The reduction in the photosynthetic rate of yerba mate intercropped with black oat represents competition for water and light factors, as previously observed when yerba mate was grown in the presence of the weed species Bidens pilosa and Ipomoea indivisa (David et al, 2018). The photosynthetic rate is directly related to the availability of water and light incidence on the plants (Devin et al, 2023).…”

Fatores que afetam a produtividade na cultura da erva-mate

“…Isso indica que os produtores percebem a necessidade de aplicação dessa prática, provavelmente pressionados pela baixa reposição nutricional dos ervais, como visto acima. De fato, a competição com plantas daninhas é um fator importante para a erva-mate, afetando tanto os aspectos fisiológicos como os nutricionais(DAVID et al, 2018), principalmente nas fases mais jovens da cultura.Por outro lado, a proteção das mudas após o plantio e a eliminação de ramos doentes ou atacados por pragas tiveram baixa adoção, embora crescente com o aumento do nível de produtividade (Tabela 3). A proteção de mudas no plantio consiste na colocação de controle de pragas e doenças da erva-mate.…”