Abstract
The objective of this study is to evaluate the interference of reduced spacing in the physiological and characteristics production components of maize hybrids (Zea mays L.). Four line spacings (95, 80, 60 and 40 cm) were tested using three commercial hybrids (H1, H2 and H3) in Senador Guiomard, Acre, Brazil. The experimental design of randomized complete blocks was used in subdivided plots. The experiment lasted four months, where the parameters measured were CO2 assimilation and gas exchange, water use and carboxylation efficiencies and productivity. Reduction in spacing did not influence the photosynthesis, with slightly differences at stomatal conductance and transpiration. However, it was observed that the H3 presented higher efficiency of water use and carboxylation at the larger spacings. Moreover, there was an increase in the number of ears and grain yield per hectare in reduced spacing, with H3 plants presenting a superior mass of 100 grains among the cultivars. It is concluded that H3 (P4285YHR) presents essential physiological characteristics favouring yields at reduced spacings compared to crops requiring larger spacing. In addition, reduced spacing lines for the maize crop do not reduce atmospheric CO2 assimilation, resulting in larger productivity per cultivated area among the three tested hybrids. Key words: Production, photosynthesis, Zea mays.  
Highlights
Maize is widely cultivated around the world, in many different soils and climate, mainly because of its large domestication
The objective of this study is to evaluate the interference of reduced spacing in the physiological and characteristics production components of maize hybrids (Zea mays L.)
There was an increase in the number of ears and grain yield per hectare in reduced spacing, with H3 plants presenting a superior mass of 100 grains among the cultivars
Summary
Maize is widely cultivated around the world, in many different soils and climate, mainly because of its large domestication. At the level of world production, Brazil takes the third place, standing behind United States and China (ABIMILHO, 2017). Brazilian states with the largest production of maize grains in 2015/16 were Mato Grosso do Sul (9000 kg ha1), followed by Paraná (7953 kg ha-1) and Goiás (7800 kg ha-1). At the North region, Acre state is in an intermediary position, which had a productivity of 2350 kg ha-1, in the same period (CONAB, 2017). The low productivity of Acre can be attributed to use of low-yield cultivars by the producers in addition to inadequate use of plant spacing among lines, reaching one meter (Queiroz et al, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
