Authors:
Queli Ruchel
, Dirceu Agostinetto
, Renan Ricardo Zandona
, Andre da Rosa Ulguim
,
Roberto Avila Neto
, Diego Severo Fraga |
Abstract:
Production potential of soybean crops may be negatively affected by their competition with
weeds, since species that are morpho-physiologically close to these crops tend to have similar
requirements for resources, a fact that intensifies competition. Therefore, this study aimed at
evaluating the relative competitive ability of soybean (C3) against both weeds blackjack (C3) and
slender amaranth (C4), by considering growth variables. Experiments were carried out as
replacement series of soybean with blackjack (first experiment) and slender amaranth (second
experiment). Populations of plants in the first and the second experiments were 14 and 10 plants
pot-1
, equivalent to 337 and 241 plants m-2
, respectively. Ratios under investigation were 100:0
(soybean monoculture), 50:50 and 0:100% (weed monoculture). Variables under evaluation were
height, leaf area and shoot dry matter. Results show that soybean was more competitive than
blackjack, whereas slender amaranth was more competitive than soybean. In general, in the cases
of C3 species (soybean and blackjack), interspecific competition was predominant and led to
decrease in growth variables, while, in the case of slender amaranth, intraspecific competition led
to higher loss than the interspecific one. |
