The competitive ability of crops against weeds depends on factors related to their ability to maintain productivity or eliminate them in a situation of interference. This study aimed to evaluate the effects of competition between three varieties of maize and six weed species on the growth and dry mass allocation by plants. A factorial scheme 3 x 6 + 9 was arranged consisting of a combination of three genotypes of maize (DKB 390 YG, variety and hybrid AL 25 SHS 4080) in competition with six weed species (Bidens pilosa, Cenchrus echinatus, Brachiaria brizantha, Commelina benghalensis, Brachiaria plantaginea and Euphorbia heterophylla), plus nine treatments corresponding to the maize and weed cultivars under no competition. Both treatments were designed in randomized blocks with four replicates and each pot (containing 5 dm3) was an experimental unit. The period of coexistence among the maize and weed cultivars was 60 days after emergence, and thereafter the plant material collected was evaluated to assess the dry mass distribution among different organs (roots, leaves and stems). The maize cultivars presented lower dry mass accumulation when in competition with the weed species. The leaves and stems were the main organs negatively affected. On the other hand, the roots of the competing species were, in general, the most affected. AL 25 genotype was the least tolerant maize variety in competition with weeds and B. plantaginea was the least competitive weed. B. brizantha and C. benghalensis proved to be the species with the greatest capacity to compete with maize.
Bidens pilosa; Cenchrus echinatus; Brachiaria brizantha; Commelina benghalensis; Brachiaria plantaginea; Euphorbia heterophylla
