Soybeans Competitiveness with Morning Glory

Abstract

-Weeds interfere negatively on development, yield and quality of soybeans (Glycine max). Inadequate weed control by herbicide use can select for resistant or tolerant biotypes, leading to a shift in the weed flora. An example is the increase of incidence of morning glory (Ipomoea spp.) in soybeans growing areas in South Brazil. The aim of this study was to determine the competitiveness of soybeans intercropped with I. triloba, I. indivisa and I. purpurea through a replacement experiments series. Greenhouse experiments were conducted in a completely randomized design with four replications. The first experiment was carried out aiming to get the plant population while total plant dry mass remained constant. Other experiments were done under replacement series experiments with soybeans and morning glory ratios of 100:0, 75:25, 50:50, 25:75 and 100:0 using the 250 plant m -2 defined by the preliminary experiment. Leaf area, root and shoots dry mass were assessed. Diagrams along with index interpretation were used to performed a competitiveness analysis. Soybeans showed greater competitiveness as I. triloba, I. purpurea and I. indivisa species for the leaf area, root and shoots dry mass variables. Intraspecific competition prevails between soybean plants whilst interspecific competition prevails for morning glory.Keywords: competition, I. triloba, I. indivisa, I. purpurea, replacement series. de-viola de 100:0, 75:25, 50:50, 25:75 e 100:0, com RESUMO -As plantas daninhas interferem negativamente no desenvolvimento

Competitive interaction between soybean cultivars and Sida rhombifolia

“…This demonstrates that both species are not equal competitors for environmental resources, with soybeans being more competitive than arrowleaf sida. When soybeans competed with different species of Ipomoea spp., the crop stood out when compared to the weed, presenting greater efficiency in capturing environmental resources (Piccinini et al, 2016).…”

“…Many weed species, such as wild poinsettia, beggarticks, crabgrass, alexandergrass, tropical sipderwort, morning glory, joint-vetch and others, compete with crops for water, light, and nutrients. In addition, some can release allelopathic substances, as well as host insects and diseases, which result in great losses (Piccinini et al, 2016;Forte et al, 2017;Ruchel et al, 2019).…”

Neem (Azadirachta indica) Oil Affects Morning Glory (Ipomoea purpurea) Seedling Development

“…In addition, some biotypes in Brazil have already developed herbicide tolerance (Pazuch et al 2017) and they serve as a reservoir for plant pathogens such as bacteria Xylella fastidiosa Wells (Wistrom and Purcell 2005) and insects (Simms and Rausher 1989). In soybeans, for example, losses of 27 to 45% have been reported (Piccinini et al 2016). Such factors should be considered a warning for the future difficulty of managing this weed plant in Brazil.…”