High Sunflower Densities as a Weed Control Strategy in an Integrated Crop-Livestock System

Abstract

Sunflower is an important crop for Integrated Crop-livestock Systems (ILCS), and one of the main management difficulties identified in this crop is weed control, especially under no-till conditions when chemical weed control is not allowed. Therefore, the aim of this research was to evaluate the effect of greater sunflower population density on weed control, and its impact on sunflower yield, in an ILCS with eucalyptus in an Environmental Protection Area. Two population densities were tested (45 and 90 thousand pl. ha-1) in two crop systems (sunflower monoculture and sunflower-eucalyptus integration). An additional treatment was provided in the sunflower-eucalyptus integration, and 5 positions (2,4; 4,8; 7,2; 9,6; and 12 m) between the tree rows were evaluated. In a randomized block design, with eight repetitions, weed density and weed dry matter were determined at 40, 70 and 100 days after crop emergence. Also, phytosociological indices were calculated. The following yield components were evaluated: head diameter, number of achenes per head, and 1000-achene weight. There was lower weed infestation on the high density treatment in both systems. There was no difference of weed occurrence in the 5 positions between the tree rows. Sunflower yield was higher in the greatest population density in both systems. Increasing population density in sunflower crop is a practicable management to control weeds and to gain higher yield under free-herbicide conditions.

Fitossociologia de plantas daninhas em área de patoreio no Município de Caturité, Região do Cariri Paraibano, Brasil

“…A predominância de espécies daninhas das Famílias Poaceae e Asteraceae como infetantes nos sistemas agropecuários já foi observada por outros autores (Lamengo et al, 2015;Rodrigues et al, 2017;Dominschek et al, 2019). De acordo com Braga et al (2012) estas duas famílias estão entre as mais representativas quando se fala em plantas daninhas na lavoura e na pecuária, sendo por esse motivo consideradas as principais famílias de plantas daninhas do Brasil (Oliveira e Freitas, 2008).…”

Land-Use Intensification Trends in the Rio De La Plata Region of South America: Toward Specialization or Recoupling Crop and Livestock Production

“…Integrated production of beef cattle and eucalypts has been shown to be profitable and to provide ecological benefits [53] . In addition, integration of cash crops and livestock with trees can be an effective way to diversify production and income, which could be important to the Rio de la Plata region considering that commercial wood plantations (mainly eucalypts) have been increasing in the region [54] . The integration of animals (mainly sheep) grazing interrow/undercanopy vegetation in vineyards and orchards has been a trend in other parts of the world [55] , but the existence of this ICLS model remains anecdotal in Rio de la Plata and consists of an opportunity for research and development.…”