Crop management and its effects on weed occurrence

The objective was to evaluate weed phytosociology and similarities between crop management systems in the Chapadões region. The experiment was conducted at in agricultural area located in the municipality of Chapadão do Sul, MS, during the 2016/17 harvest. Three crop managements strategies were used: (1) cotton/soybean/Urochloa, (2) millet/soybean/millet and (3) millet/soybean/crotalaria. A phytosociological survey of weeds was carried out during soybean cultivation and cover crops growth, in succession. The evaluation area for each management strategy was 0.5 ha. Soybean surveys were carried out in October and January, while the cover crop surveys were performed in February and May. The relative frequency (RF), relative density (RD), relative abundance (AR), and relative importance (RI) of weeds, Venn diagram, and Jaccard and Sorenson similarity indices were evaluated. The management area represented by the cotton/soybean/Urochloa rotation had fewer weed species than others. The species Cenchrus echinatus, Digitaria insularis, Digitaria sanguinalis, Eleusine indica and Commelina benghalensis had the highest phytosociological indeces among the monocotyledons. Attention is required for managing the dicotyledons Amaranthus deflexus, Conyza canadensis and Senna obtusifolia despite their low indices because of herbicide resistant cases. The highest indeces of similarity were found between managements areas 2 and 3, which did not rely on cotton cultivation prior to soybeans.

Percepción etnobotánica de los campesinos sobre la flora arvense en fincas de la agricultura suburbana en Santiago de Cuba, Cuba / Ethnobotanical perception of the farmers about the weed flora in farms of suburban agriculture in Santiago de Cuba, Cuba

Currently the weed species are a resource to conserve. The objective was to evaluate the ethnobotanical perception of the peasants about the weed flora in farms of suburban agriculture in Santiago de Cuba, Cuba. An ethnobotanical study was developed and the percentage of known species, percentage of species per management action and the percentage of weed species with potential utility was determined. The spectrum of use, the categories of use and the species richness by category were also taken into account. The weed species found in each of the farms were identified by at least 60% of the producers conferring more than 70% of this flora potential utilities such as medicinal, animal feed and agricultural. Although different forms of management for these species were identified, more than 40% are eliminated regardless of the potential benefits that productive systems can bring to this.

Actualmente las especies arvenses son un recurso a conservar. El objetivo fue evaluar la percepción etnobotánica de los campesinos sobre la flora arvense en fincas de la agricultura suburbana en Santiago de Cuba, Cuba. Se desarrolló un estudio etnobotánico y se determinó el porcentaje de especies conocidas, porcentaje de especies por acción de manejo y el porcentaje de especies arvenses con utilidad potencial. También se tuvo en cuenta el espectro de uso, las categorías de uso y la riqueza de especies por categoría. Las especies arvenses que se encuentran en cada una de las fincas fueron identificadas por al menos el 60% de los productores confiriéndoles a más del 70% de esta flora utilidades potenciales como medicinal, alimento animal y agrícola. Aunque se identificaron diferentes formas de manejo para estas especies, más del 40% resultan eliminadas independientemente de los beneficios potenciales que puedan aportar a estos sistemas productivos.