although, grapevines do not have a high chilling requirement, its fulfillment is critical for normal development of the vines. in tropical and subtropical regions such as farrashband, in the south of iran, there is no adequate winter chilling to release bud dormancy in grapevines. so it is necessary to consider the effect of chemical dormancy–breaking agents on bud dormancy. in the present rese...

in this research, chilling and heating requirements of six local cultivars of apricot (jafari, ghavami, jahangiri, khiari, khiveaee and rajabali) were evaluated under field and lab conditions. under lab condition, ‘rajabali’ and in some extent ‘johangiri’ began flowering after 500 hours in 4°c. other cultivars except ‘khiari’ flowered at 750 h. ‘khiari’ flowered at 1000 h. in field, due to litt...

no sufficient of chilling is a major problem in producing temperate fruit in warm climates. so determination of chilling requirement of different cultivars of grape is important. the aim of this research was determination of chilling requirement of four grape vine commercial cultivars including: kolahdary, red rasin, yaghoti and white rasin that factorial experiment based on a completely random...

Determining of chilling and heat requirements of olive cultivars growing in Fars Province is important for the selection of cultivars that will exhibit satisfactory growth and development. The purposes of this study were determining the chilling and heat requirements of olive and comparison of Utah and Positive Utah Chill unit (PCU) models for determining the chilling requireme...

With global warming, an advance in spring leaf phenology has been reported worldwide. However, it is difficult to forecast phenology for a given species, due to a lack of knowledge about chilling requirements. We quantified chilling and heat requirements for leaf unfolding in two European tree species and investigated their relative contributions to phenological variations between and within po...

It is usually thought that adequate winter chill is required for the full flowering of many temperate woody species. This paper investigates the sensitivity of blackcurrant bud burst and flowering to natural weather fluctuations in a temperate maritime climate, and compares a range of chill models that have been proposed for assessing the accumulation of winter chill. Bud break for four contras...

In Liquidambar sfyraciflua L., 1200 to 1600 hours of chilling (3 D C) resulted in rapid resumption of growth under greenhouse forcing conditions. Long photoperiods were effective substitutes for chilling. Plants from southern Alabama (Lat. 31°) had a lower chilling requirement than those from western Tennessee (Lat. 36°). Growth rate of plants under long photoperiod varied directly with degree ...

Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff...