The use of phenological data to calculate chilling units in Olea europaea L. in relation to the onset of reproduction

Abstract

The aim of this study was to develop a practical method to evaluate the effective relationship between the amount of winter chilling and the response expressed as the spring reproductive re-starting dates in the olive (Olea europaea L.). Two olive cultivars growing in a special olive orchard in Umbria (central Italy) were studied over a 3-year period (1998-2000): the cultivar Ascolana, typical of central Italy, and the cultivar Giarraffa, typical of southern Italy. The spring reproductive restarts were assessed using data from detailed phenological observations made on 60 trees of each cultivar in an effort to establish the exact date of reproductive bud swelling. The chilling phenomenon was evaluated by using 341 functions derived from a formula developed by researchers at Utah State University to calculate chilling units. The mathematical functions are defined, and show the very close relationship between the amount of winter chilling and the spring reproductive response in the two cultivars in the orchard studied. The results can be used to define the relationship between local climate and plant development, and the mathematical approach can be used to draw maps that can show the suitability of different cultivars on the basis of local climatic conditions.

Two statistical approaches to forecasting the start and duration of the pollen season of Ambrosia in the area of Lyon (France)

“…Many authors have forecast the SDP of various plants, using meteorological parameters; regardless of the procedure, temperature was the most frequently used parameter (Lejoly-Gabriel 1978;Niqueux and Arnaud 1981;Törnevik 1982;Richardson and Anderson 1986;Linvill 1990;Andersen 1991;Frenguelli et al 1991;Sutra et al 1992;Larsson 1993;AntØpara et al 1995;Recio et al 1997;Gonzales Minero et al 1999;Garcia-Mozo et al 2000;Orlandi et al 2002). On rare occasions, radiation or evapotranspiration (Durand 1967), or sometimes several meteorological factors like temperature, wind and rainfall (Mandrioli et al 1993;Fornaciari et al 1998;Laaidi 2001a, b) were used.…”

The detection of climate impacts: some methodological considerations

“…Less than 10 years of results have been used in many published studies (e.g. Veit et al, 1997;Koontz et al, 2001;Martin, 2001;Orlandi et al, 2002;Sergio, 2003;Sainio et al, 2004) and 8 years have been used as a minimum series length to qualify as 'long-term' (e.g. Wiens, 1984;Houlahan et al, 2000).…”

Phenology, aerobiology and production of an olive grove in Almodóvar del Campo (Castilla-La Mancha)

“…Han estudiado la fenología del olivo, entre otros, ALCALÁ & BARRANCO, 1992;BARRANCO & al, 1994;NIEDDU & al, 1997;FORNICIARI & al, 2000;ORLANDI & al, 2002. La aerobiología se ocupa del estudio de las partículas bióticas en la atmósfera y de la influencia de las variables meteorológicas sobre el nivel de cada tipo.…”