Phytosociological Survey of Weeds in Cultivars of Common Beans With Different Types of Growth in the North of Minas Gerais

Abstract

-The objective of this paper was to characterize the phytosociology of weeds in function of different types of growth of common bean cultivars in the North of Minas Gerais. The study was conducted in the experimental area, located in the municipality of Janaúba, MG. The treatments consisted of eight commercial cultivars of common beans with different types of growth. The design was done in randomized blocks, with three replications. The soil preparation was conventional and the planting was done in June, with manual seeders, with a 0.5 m spacing between rows. The phytosociological survey was performed in two phases of bean cultivation, in stages V3 and R8. The method used was the square inventory one, with a 0.25 m 2 frame, randomly released once in each plot. Samples of each square were identified and quantified by family, genus and species, and the sampled plants were collected with their complete structure. Next, the material was sent to a drying greenhouse with forced air circulation at 65 o C for 72 hours, for drying and determination of weight of dry matter. We also estimated the Relative Frequency, Relative Density and Relative Abundance to determine the importance value index and similarity index. At the V3 stage, the species Sorghum halepense, Brachiaria plantaginea and Boerhavia diffusa had higher importance value indexes. At the R8 stage, the Amaranthus viridis specie showed higher importance value index and dry matter. In more prostrate cultivars, the weeds present lower importance value indexes at the R8 stage.

Periods of weed interference in cowpea crop in the semi-arid of Minas Gerais, Brazil

“…Weeds are consistent with other surveys conducted in the studied region (Batista et al 2016;Batista et al 2017;Guerra et al, 2017) indicating a seed bank in the soil where some species stand out in relation to others depending on weather conditions and cultivated crop.…”

“…For that matter, the determination of interference periods is essential to increase crop yield. Studies determined the period before interference (PBI), total interference prevention (TPIP) and critical period for weed control (CPWC) in several crops (Oliveira et al, 2016;Tursun et al, 2016;Singh et al, 2017). However, for the cowpea crop, research is still scarce (Matos et al, 1991;Freitas et al, 2009;Adigun et al, 2014;Yadav et al, 2018) and it is necessary, mainly, for the conditions of the semi-arid region from Minas Gerais.…”

Floristic study of weeds in watermelon crops in Savannah of Roraima, Brazil

“…As famílias com maior número de espécies encontradas na área foram Poaceae (5) e Fabaceae (3). Vários outros trabalhos recentes corroboram com este resultado (Batista et al, 2016;Mesquita et al, 2016;Santos et al, 2016;Evangelista et al, 2015;Albuquerque et al, 2014;Cunha et al, 2014 indivíduos.m -2 ), apesar da baixa frequência (presente em 5% das amostras). Assim, apesar de ser uma espécie com indivíduos distribuídos desuniformemente na área, nas amostras em que eram encontrados, esses indivíduos estavam em grande número, ocupando a maior parte da área amostrada.…”

Weed Vegetation Structure in an Area of Organic Acerola Cultivation, Parnaíba, Piauí, Brazil

“…The species with the highest relative cover values were Urochloa plantaginea, Commelina benghalensis, Cynodon sp., Panicum maximum, and Amaranthus spinosus (Table 1). Urochloa plantaginea is considered one of the most damaging invasive species in the Poaceae family due to its efficient environmental occupation and easy proliferation and growth, and its presence can cause agricultural damage due to competition with crops (Batista et al, 2016). The species has already been cited by Costa et al (2014) as one of the most common grasses in south and southeastern Brazil.…”

“…Species such as Amaranthus spinosus and Panicum maximum also achieved significant cover values within the studied area. The Amaranthus genus is difficult to manage because of the large number of seeds it produces and its longevity and viability in the soil, in addition to its quick development and short life cycle (Carvalho, 2013;Batista et al, 2016). The presence of Panicum maximum in arable areas can incur management costs given the difficulty of eliminating the propagules of the species that remain in the soil and can resist burning, allowing successive invasion cycles (Oliveira and Freitas, 2008).…”