Basal temperature and thermal sum in phenological phases of nectarine and peach cultivars

Adilson Pacheco De Souza,Andréa Carvalho Da Silva,Sarita Leonel

doi:10.1590/s0100-204x2011001200002

Adilson Pacheco De Souza, Andréa Carvalho Da Silva + Show 1 more

Open Access

https://doi.org/10.1590/s0100-204x2011001200002

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Abstract

The objective of this work was to evaluate basal temperature, thermal sum at different phenological stages, phenological phase duration, yield and seasonality of one nectarine and 14 peach cultivars, between 2006 and 2009. The considered phenological phases were: pruning-sprouting; sprouting-flowering, from swollen bud to open flower; flowering-fruiting, from petal fall to medium-sized fruit; and ripening. Minimum basal temperatures (Tb) obtained were: pruning-sprouting, 8°C, irrespective of the cultivars; sprouting-flowering, 10°C, except for 'Cascata 968', which required 8°C Tb; flowering-fruiting, 12°C, except for 'Oro Azteca', which required 14°C Tb; ripening, 14°C, except for 'Sunblaze', 'Diamante Mejorado' and 'Precocinho' with 12°C Tb. For most cultivars, the maximum basal temperatures were 30, 34, 34 and 28ºC for phases pruning-sprouting, sprouting-flowering, flowering-fruiting and ripening, respectively. 'Turmalina', 'Marli' and 'Tropic Beauty' showed average yields of 3,945.0, 3,969.3 and 3,954.0 kg ha-1, respectively, in 2009, while the nectarine 'Sunblaze' showed around 3,900 kg ha-1 in 2008 and 2009. The cultivars differed for their total cycle and for the accumulated thermal sums which varied, respectively, from 245 days and 1,881.4 degree-days for 'Oro Azteca', to144 days and 1,455.7 degree-days for 'Precocinho'.

Highlights

The advance in peach and nectarine production, in regions of subtropical climate with milder winters, is related to the development of specific cultivars, their behavior in different localities, and the use of special auxiliary techniques for cultivation
There was a slight difference in the standard deviation, in days (Figure 1), for the preestablished temperatures, due to the low variability of data on maximum, minimum and mean temperatures in the four productive cycles, except for the sprouting‐flowering phase, which occurred between the middle of September and the end of October for most evaluated cultivars, when the monthly mean values of air temperature had the greatest variation
According to Souza et al (2009), the pruning time does not interfere with the values of the basal temperatures for the same cultivar

Summary

Introduction

The advance in peach and nectarine production, in regions of subtropical climate with milder winters, is related to the development of specific cultivars, their behavior in different localities, and the use of special auxiliary techniques for cultivation. The cultivars developed for SP, with varied fruit ripening cycles, meet market demands from September to February, providing consumers with different types of peaches and nectarines (Barbosa et al, 1997; Ramos & Leonel, 2008). 2011 million plants, including nectarine, which accounts for 15% of the peach culture in number of plants (Barbosa et al, 2003; Pedro Júnior et al, 2007). The expansion of these cultures has been limited by certain major factors, such as insufficient regional tests to indicate which cultivars are adapted to different ecological regions, as well as the lack of phenological characterization for the existent genotypes, and the thermal requirements as to chilling hours for the normal vegetative and flower development. The ripening time depends on the flowering time and on the duration of fruit development, which is regulated by the thermal range from flowering to ripening and by the cultivar response to temperature (Marra et al, 2002; Day et al, 2008)

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