Search results for " growing degree hours"
showing 4 items of 4 documents
Heat requirements for loquat fruit development may be assessed with a Beta model approach
2018
In Mediterranean areas, loquat trees (Eriobotrya japonica Lindl.) typically bloom in fall and fruits develop during the winter period, reaching their ripening in spring. So far, little interest has been driven towards models capable of estimating heat requirements for the accomplishment of fruit development in the winter period. In this work, we verified whether in Mediterranean areas the heat accumulation (GDH) needed for loquat fruit growth, may be precisely described using a Beta model, a flexible mathematical function which, in the past, has been successfully used in peach. BBCH phenological stages of ‘Algerie’ trees were recorded in two experimental sites: Palermo, Italy (38°04’N, 13°2…
THERMAL TIME REQUIREMENT AND HARVEST TIME FORECAST FOR PEACH CULTIVARS WITH DIFFERENT FRUIT DEVELOPMENT PERIODS
2002
Non-linear models using growing degree hours (GDH), based on the choice of base, critical and optimum temperatures, have been successfully applied to calculate thermal time required for spring bud burst in deciduous fruit trees. The flexibility of the model can fit the wide range of temperatures that occur during the peach fruit development period (FDP), which takes place from early spring to late summer. In this experiment, fruit growth was studied in relation to thermal time accumulated from bloom to fruit harvest for peach and nectarine cultivars whose fruit development period range from 70 to 150 days. Thermal time was calculated in terms of degree days (DD) (base temperature 7 °C, and …
Estimation of chilling and heat requirements of six sweet cherry (Prunus avium L.) cultivars
2022
Warmer winters without sufficient chilling due to climate change in Mediterranean regions represent a threat for deciduous fruit tree species such as sweet cherry (Prunus avium L.) with high chilling requirement, since it will affect fruit tree phenology leading to dramatic yield reduction and fruit industry income loss. Quantifying chilling requirements to overcome winter dormancy is crucial for identifying suitable cultivars for a given site, for predicting the necessity and timing applications of rest-breaking chemicals and the possible consequences of climate change. The aim of the following study was to determine the chilling and heat requirements of six sweet cherry cultivars grown in…
Esigenze bio-termiche e stima del periodo di sviluppo del frutto in cultivar di pesco a differente epoca di maturazione
2009
In this experiment carried out in Sicily (37.35N 12.58E), fruit growth was studied in relation to thermal time accumulated from bloom to fruit harvest for peach cultivars whose fruit development period ranges from 76 to 170 days. Thermal time was calculated in terms of GDH (base temperature 6.2-10 °C, optimum temperature 23.3-24.5 °C and critical temperature 33.7-39.4 °C) by the use of non-linear models. Climatic and phenological data (bloom and harvest dates) were considered for a minimum of four to a maximum of six years. Taking into account the whole FDP, the accuracy of the GDH model in predicting harvest time ranged from 0.6 day, in the early ripening peach cultivar Anita, to 6.4 days …