SciELO - Scientific Electronic Library Online

 
vol.66 issue2Influence of six rootstocks on yield of superior rubber tree clonesSoil aggregation resulting from sewage scudge application author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Bragantia

Print version ISSN 0006-8705On-line version ISSN 1678-4499

Abstract

SILVA, Alexandre de Almeida e; VARANDA, Elenice Mouro  and  RASSINI, Joaquim Bartolomeu. Weather, cultivar and density-dependent processes influence on aphid in alfalfa. Bragantia [online]. 2007, vol.66, n.2, pp.285-290. ISSN 1678-4499.  https://doi.org/10.1590/S0006-87052007000200012.

It is important to understand the effects of weather, insect density and plant cultivar on insect abundance to predict and prevent crop production loss. The present work investigated the influence of such factors on aphid in alfalfa during one year (short term). Data was collected from September/1997 to August/1998 at Canchin Farm (CCPSE-EMBRAPA), São Carlos, State of São Paulo, Brazil. Weather conditions had, in general, little effect on the variation of aphid populations, but Therioaphis maculata abundance was negatively correlated to humidity. Moreover, high maximum temperatures and low levels of rainfall possible favored T. maculata high abundance on Crioula and P3 cultivars. Therefore, appropriate management of this species is required during hot and dry periods. Population variation of Acyrthosiphon spp., T. maculata and Aphis craccivora seems to be regulated by density dependent processes. Resistant cultivar CUF 101 had a lower abundance of T. maculata and A. craccivora and a narrower population variation than the other cultivars and may reduce their abundance on field. Long-term studies on population dynamics including the effect of climatic conditions and density-dependent factors on plant quality will contribute to pest management in alfalfa fields.

Keywords : Herbivory; Hemiptera; Medicago sativa; resistance; population dynamics.

        · abstract in Portuguese     · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License