Phytosociology of weed community in no-burn sugar cane agroecosystems

Planta Daninha

Alves, P.L.C.A.¹  Salgado, T.P.¹  Kuva, M.A.¹  UNESP, Jaboticabal¹  Herbae Consultoria e Projetos Agrícolas Ltda, Jaboticabal¹  Pitelli, R.A.¹ 

关键词: Cyperus rotundus;    Ipomoea spp.;    aggregation index;    similarity index.;   

DOI  :  10.1590/S0100-83582007000300009

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

A study was carried out in northeastern São Paulo, Brazil to evaluate the similarity between species composition and phytosociological index in weed communities of no-burn sugar cane crop harvest at different times and number of cut-cycles. Assessments were carried out in twenty-eight sugar cane plots in the Ribeirao Preto-SP region. In each plot, collection and evaluation areas were established, two per hectare, kept without control and used as weed sampling sites. The samplings were made using squares (0.5 x 0.5 m), randomly cast twice in each area. Weed density and biomass were evaluated per species 120 days after sugar cane harvesting. The phytosociological studies showed that Cyperus rotundus presented the highest values of relative density, dominance, frequency and relative importance index. The seed-propagated dycot plants also presented high values for phytosociological index, mainly the species belonging to the families Euphorbiaceae and Convolvulaceae. On the other hand, the grass weeds, traditionally found in burned sugar cane areas, had very little relevance under the no-burn system. The diversity index (Shannon - H) varied from 0 to 1.61 and the similarity index(S) was low, except when groups of weeds were compared. The majority of the weed populations showed geographic distribution in match pattern. Areas with high infestation of C. rotundus and/or Convolvulaceae species showed the highest aggregation index.

【 授权许可】

Unknown