Biblioteca Digital do Instituto Politécnico de Bragança   Instituto Politécnico de Bragança

Biblioteca Digital do IPB >
Escola Superior Agrária >
Produção e Tecnologia Vegetal >
PTV - Artigos em Revistas Indexados ao ISI >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10198/4236

Título: Apple orchard frost protection with wind machine operation
Autor: Ribeiro, A.C.
Abreu, J.P. Melo e
Snyder, R.L.
Palavras-chave: Frost protection
Malus pumila Mill.
Wind machine
Night cooling
Freeze damage
Issue Date: 2006
Editora: Elsevier
Citação: Ribeiro, A.C.; De Melo-Abreu, J.P.; Snyder, R.L. (2006) - Apple orchard frost protection with wind machine operation. Agricultural and Forest Meteorology. ISSN 0168-1923. 141:2-4, p. 71-81
Resumo: Research has shown that wind machines are more effective under conditions of strong thermal inversions. Quantitative relationships between the level of protection and inversion strength, however, are not well known, and there are few reports on the effect of fan operation on energy balance. Whether the wind machines should be started before surface cooling causes turbulence damping and atmospheric stratification or if it is possible to delay starting until just before the critical temperature occurs remains a matter of discussion. Therefore, experiments were conducted on 11 spring frost nights during the 1999 and 2000 to assess the effectiveness of a fan operation on frost protection of an apple orchard under different microclimatic conditions. The 11 frost events were characterized by light winds (0.58–1.92 m s−1) and clear skies for most of the night, resulting in an average accumulated radiative loss of 2.67 ± 0.38 MJ m−2. The air temperature increased immediately after the wind machines were started and the temperature rise depended on inversion strength. For each 1 °C increase in temperature inversion strength between 1.5 and 15 m height, wind machine operation caused a 0.3 °C increase of air temperature at a 1.5 m height within the main area affected by the fan operation. Using multiple regression, the area protected was significantly related to the temperature increase and the inversion strength. Wind machine operation reduced flower damage by 60% in 1999 and 37% in 2000. Distribution of flower damage varied spatially, and it was related to wind drift.
Arbitragem científica: yes
URI: http://hdl.handle.net/10198/4236
Versão do Editor: http://www.sciencedirect.com/science/journal/01681923
Appears in Collections:PTV - Artigos em Revistas Indexados ao ISI

Files in This Item:

File Description SizeFormat
Ribeiro AC.pdf942,53 kBAdobe PDFView/Open
Restrict Access. You can request a copy!
Ribeiro - resumo.pdf74,04 kBAdobe PDFView/Open

Statistics
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpaceOrkut
Formato BibTex mendeley Endnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 


  © Instituto Politécnico de Bragança - Biblioteca Digital - Feedback - Statistics
  Estamos no RCAAP Governo Português separator Ministério da Educação e Ciência   Fundação para a Ciência e a Tecnologia

Financiado por:

POS_C UE