Modeling the phenology of ¿royal gala¿ and ¿fuji suprema¿ apple trees in function of the climate, in the Vacaria region, Brazil / Modelagem aplicada à fenologia de macieiras Royal Gala e Fugi Suprema em função do clima, na região de Vacaria, RS

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2011

RESUMO

The production of apple in Southern Brazil is limited by climate conditions. Low and continuous air temperature during winter seasons are indispensable to plants for initiating a new vegetative cycle, and for an adequate budding and flowering. Besides of low temperature in winter, thermal conditions in spring and summer seasons have also influence in plant development. Therefore, the phenology of apple trees depends on climate conditions. The main objective of this work was to adjust models for estimating the occurrence of phenological stages of ¿Royal Gala¿ and ¿Fuji Suprema¿ apple trees in function of climate conditions, in the Vacaria region, Brazil. Meteorological data of the 1983-2009 series were provided by Embrapa Uva e Vinho. Mean values from that period were compared to climate means (1931-1960 and 1961-1990), and temporal trends were tested. A phenological data base was collected in six different locations, from the 2003/2004 to 2009/2010 cropping seasons. A mean crop phenology was characterized in terms of number of days and degree-days. Regression models were adjusted for estimating the number of days between bud breaking treatment and several phenological events as a function of the hibernal cold, degree-days and air temperature. The annual mean precipitation was higher than the climate normal means, and a tendency of increasing rainfalls was detected for spring seasons. Temporal tendencies of increasing minimum air temperature, as well as reducing number of cold hours were detected. The availability of hibernal cold showed high variability among years, and the months from May to July have the highest contribution. The requirement of cold units for breaking of bud dormancy in ¿Royal Gala¿ and ¿Fuji Suprema¿ apple trees is not achieved, even in the coldest winters. Estimation of initiate blooming as function of the accumulated cold is not possible if the orchard received bud break treatments. The apple phenology varied among cropping seasons, in particular due to conditions of air temperature. The duration of phenological stages increases as the air minimum temperature decreases. The occurrence of phenological events after bud break treatment can be estimated as function of accumulated degree-days. However, the precision of the estimative is higher if including the minimum and mean air temperatures to degree-days.

ASSUNTO(S)

maçã zoneamento climático vacaria (rs) fenologia meteorologia

ACESSO AO ARTIGO

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