Initial Development of Sunflower (Helianthus annuus L.) under Weed Competition with Different Species of Grasses
Lara Maisa da Silva Alcântara
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
Lucas Aparecido Manzani Lisboa *
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil and São Paulo State University (UNESP), College of Technology and Agricultural Sciences, Dracena, São Paulo, Brazil
Silvia Maria Marinho Storti
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
Ana Eliza da Silva Lima
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
Nubia Priscila de Olibveira Crispim
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
Gabriel Geminiano da Silva
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
Alan dos Santos Cardoso
Integrated College Stella Maris (FISMA) and Educational Foundation of Andradina (FEA), Andradina, São Paulo, Brazil
*Author to whom correspondence should be addressed.
Abstract
Introduction: All cultivated plants are subject to intra and interspecific grass competition, once this competition may gradually increase within the crop cycle.
Objective: In view of the above, this work aims to evaluate the initial development of sunflower, when submitted to competition with different species of grasses.
Material and Methods: A randomized block design was installed in a 2x4 factorial scheme, with two grass species, Urochloa decumbens cv. Basilisk and Panicum maximum cv. Mombasa, with four densities of competition with grasses, plus a control group (absence of grass) and four replications, total of 36 plots.
Results and Discussion: During the sowing of the grasses, the following densities were considered: low; average; high and very high density of competition. While there was an increase in density of competition, sunflower development was impaired.
Conclusion: The initial development of sunflower was impaired, with a yield of 49.06 cm2 for each weed and Panicum maximum species caused greater damage to the crop. The aerial part and the sunflower stomata were compromised.
Keywords: Urochloa decumbens, Panicum maximum, weed, stress