Authors:
Andre da Rosa Ulguim
, Dirceu Agostinetto
, Leandro Vargas
, Renan Ricardo Zandona
, Jader
Job Franco
, Diego Severo Fraga |
Abstract:
The competition of soybean (Glycine max L.) with wild poinsettia (Euphorbia heterophylla L.)
may alter crop growth and crop yield. The objective of this study was to analyze the competitive
ability of wild poinsettia biotypes, with a low-level resistance and susceptible to glyphosate, with
soybeans. Experiments were conducted in soybean replacement series with the susceptible
biotype (11.4, from Panambi) (first experiment) or a low-level resistant biotype (21.1, from
Condor) (second experiment) in 2013/14 and 2014/15. The population of plants in the
experiments was 20 plants pot-1
(481 plants m-2
), whose tested proportions were 100:0 (soybean
monoculture), 50:50 and 0:100% (wild poinsettia monoculture). The variables were height, leaf
area and shoot dry matter. Soybeans are more competitive than wild poinsettia regardless of the
competitive biotype. The most harmful intraspecific competition was related to the culture and
the interspecific competition was related to the weed. Thus, susceptible wild poinsettia or with a
low-level resistance to glyphosate have a lower competitive ability per individual than soybeans
when they occur at the same rate. |
