Abstract

GUZMAN-MENDOZA, R.; HERNANDEZ-HERNANDEZ, V.; SALAS-ARAIZA, M. D.  and  NUNEZ-PALENIUS, H. G.. Diversity of weeds species in three monocultures from Bajio, Mexico. Polibotánica [online]. 2022, n.53, pp.69-85.  Epub Apr 04, 2022. ISSN 1405-2768.  https://doi.org/10.18387/polibotanica.53.5.

Weeds are a strong competitor for crops but, they also are an essential part of the agroecosystems, so it is better to know their ecology. The aim was to compare the abundance, richness and, diversity of weeds from monocultures of corn (mz), wheat (tg) and sorghum (sg). From November 2018 to May 2019 the crops were visited three times a month, the sampling was made by quadrants of 2 m2. All plants were identified at the species level and organized by their immigration status. Diversity index, accumulation curves were calculated, also a Kruskal Wallis test and Discriminant analysis were made to compare between weeds populations. 28 species were found, the total richness was obtained for mz and tg but it did not for sg. The corn was the cropping with more species (S= 26) and, a significantly high diversity (H= 2.94), it also was observed in native and exotic weed (H = 1.91 y H = 1.94, respectively). The weed abundance was significantly high in mz. The composition of weed populations was different between crops, the AD with 83% of variance explained separated three groups according to the type of crop, which was reflected in the structure of the weed populations. Plant communities are different between crops despite being in a spatially homogeneous environment. Hence, factors associated with the crops are influencing the diversity patterns observed. Species richness is inside of range of other agroecosystems but, diversity is higher than some studies reported for traditional and intensive farming systems. The present of native species in local diversity is a positive ecological indicator for crops.

Keywords : weeds; agroecology; agrobiodiversity.