Physiological Response of Maize and Weeds in Coexistence

Abstract

-This study aimed at evaluating the physiology of maize and weeds when living under different densities. The randomized block design with 4 replications was used. The factorial scheme 5 x 2 + 1 and 5 x 3 was adopted, for maize and weeds respectively, corresponding to weed species (Bidens pilosa, Commelina benghalensis, Urochloa brizantha, Sorghum arundinaceum and Ipomoea triloba) and infestation density (control, 15 and 30 plants m -2 ). Weeds were kept in coexistence with the maize hybrid DKB 390 PRO 2, with an additional treatment for maize plants absent of competition. It was kept in coexistence with maize hybrid DKB 390 PRO 2 besides an additional treatment with maize plants absent of competition. On day 45 and 60 after maize planting (DAP) physiological reviews were performed within the culture, and 38 days after weed transplanting (DAT), an infrared gas analyzer (IRGA) was used. There were physiological changes in maize due to the coexistence with weeds. On day 45 DAP, the competition, regardless of the weed species, caused less photosynthetic rate in maize coexisting with 15 plants m showed lower transpiration rate. U. brizantha and S. arundinaceum showed reduction in photosynthesis and transpiration, due to increased density and coexistence with maize. Keywords

Phytosociology and Behavior of Weeds in Maize as Influenced by Spatial Arrangements

“…Moreover, the narrower row and higher plant density approach of maize can reduce transpiration and photosynthesis of weeds. Barros et al (2017) described in their study the physiological response of maize and weeds living under different densities and their results further support the idea of reducing row spacing and increasing plant density on weed control. The results of our study are in agreement with those of previous and recent research (Chauhan & Johnson, 2011;Johnson & Hoverstad, 2002;Mhlanga, Chauhan, & Thierfelder, 2016;Mohammadi, Ghobadi, & Shaekheh-Poor, 2012).…”

“…The total production of maize in Brazil in the year of 2015-2016 reached 48.2 million tons and the state of Piauí represented 3.65% of that yield (CONAB, 2016). Increasing maize productivity depends directly on the technological level used in its cultivation, climate, fertilization and weed management (Barros, Faria, Tuffi Santos, Azevedo, & Governici, 2017). These factors may compromise crop development.…”

CRESCIMENTO DE MUDAS DE Peltophorum dubium (Spreng.) Taub. SOB INTERFERÊNCIA DE PLANTAS ESPONTÂNEAS E FORRAGEIRAS

“…A B. decumbens já vem sendo discutida em diversos programas de restauração em áreas degradadas, principalmente no bioma Cerrado, onde o seu controle é imprescindível, sendo apontado como um dos principais desafios para o sucesso das técnicas e um dos principais custos elencados na recuperação. U. brizantha também requer atenção, sendo apontada por apresentar redução na fotossíntese e transpiração de culturas em função do aumento da densidade e do convívio com essas espécies (BARROS et al, 2017).…”

The Phytotoxicity of Microencapsulated Peppermint Oil on Maize (Zea mays L.) Depending on the Type of Growth Substrate and Maize Cultivar

“…In the present experiment, the inhibiting effect of the substrate applied MPEO toward maize was visible already at maize emergence. Early and uniform emergence of maize is one of the crucial factors that support maize in its competitive efforts toward weeds [33][34][35][36] and ensures a high yield of maize [37]. The observed delays of emergence caused by the MPEO negatively affected maize performance also in the later stages of development (the second-leaf stage).…”