Due to concurrent plant competition, crop yield losses generally increase as their morphophysiological characteristics become more similar. The objective of this research was to evaluate the competitive effects of soybean cultivars mimicking dicotyledonous weed species on soybean cultivars holding dissimilar plant characteristics. Thus, a field experiment was carried out in Eldorado do Sul-RS. The factors and treatments compared were: three competition conditions (absence of competing plants and presence of the soybean cultivar "BRS 205" or "Cobb"), and four soybean cultivars reagents to competition ("IAS 5", "BR-16", "CD 205", and "Fepagro RS-10"). Variables related to cultivar yield and other correlatives were evaluated. Dissimilar characteristics in soybean plant cultivars such as height and maturity length, resulted in differentiated competitive ability with concurrent plants. The cultivar CD 205 of high stature and late maturity showed high competitive ability while IAS 5, of low stature and early maturity, showed low tolerance to competition, and BR16 and Fepagro RS-10 showed intermediate tolerance. Soybean cultivars holding high competitive ability as well as tolerance to competition, thus preserving their yield potential, also suppressed grain yield of competing plants.
competition; soybean cultivars; plant characteristics; competitive ability; crop yield
