African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6693

Full Length Research Paper

Phytosociology and weed interference in okra under organic cropping system

Raimundo Nonato Viana Santos
  • Raimundo Nonato Viana Santos
  • Graduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65054-970, Brazil.
  • Google Scholar
Antonia Alice Costa Rodrigues
  • Antonia Alice Costa Rodrigues
  • Graduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65054-970, Brazil.
  • Google Scholar
Maria Rosangela Malheiros Silva
  • Maria Rosangela Malheiros Silva
  • Graduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65054-970, Brazil.
  • Google Scholar
Maria Jose Pinheiro Correa
  • Maria Jose Pinheiro Correa
  • Graduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65054-970, Brazil.
  • Google Scholar
Mario Luiz Ribeiro Mesquita
  • Mario Luiz Ribeiro Mesquita
  • Graduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65054-970, Brazil.
  • Google Scholar


  •  Received: 31 October 2016
  •  Accepted: 21 December 2016
  •  Published: 26 January 2017

Abstract

A research was carried out to study phytosociology and to determine the periods of weed interference in the okra crop in organic cropping system. The experiment was laid out in a randomized complete block design with 20 treatments and four replications. The treatments were 10 periods of weed coexistence with the crop during 0-7, 0-14, 0-21, 0-28, 0-35, 0-42, 0-49, 0-56, 0-63 and 0-74 days after crop emergence (DAE) and 10 periods weed free during 0-7, 0-14, 0-21, 0-28, 0-35, 0-42, 0-49, 0-56, 0-63 and 0-74 DAE. The weeds were evaluated by the number of individuals and accumulated dry biomass of each population in the treatments. The relative frequency, relative density, relative dominance and importance value index of each species were used to determine the effect the weeds. The most important weeds based on the Importance value index were Commelina benghalensis L., Cynodon dactylon (L.) Pers., Eleusine indica L., Phyllanthus niruri L. and Alternanthera tenella Colla. The period prior to interference and the total period of interference prevention were respectively of 12 and 36 days after emergence. The weed community caused yield losses of around 51%. In okra organic cropping system, weed control should be done early to boost okra plant growth in order to provide shade on the weeds to reduce the need for long control period.

 

Key words: Abelmoschus esculentus (L.) Moench, competition, weed community.