Abstract

CARVALHO, Ruy Inacio Neiva de  and  ZANETTE, Flávio. Dormancy dynamics of 'Imperial Gala' apple tree buds during autumn and winter in a region of low chill occurrence. Rev. Bras. Frutic. [online]. 2004, vol.26, n.1, pp. 65-68. ISSN 0100-2945.  http://dx.doi.org/10.1590/S0100-29452004000100018.

This work aimed to evaluate the dormancy dynamics of one year old apple tree buds with or without supplementary chill during autumn and winter, in a region of low chill occurence. The stems were collected in Porto Amazonas, Parana State, Brazil, at intervals of 21 days from April to August (04/19, 05/10, 05/31, 06/21, 07/12, 08/02 and 08/23) and were treated or not with 1,440 hours of chill (4 to 7° C). The evaluation of dormancy was observed by the biological test of single node cuttings under controlled conditions (25° C and long days of 16 hours) by following parameters: average time for budburst (TMB), velocity of budburst (VB), final rate of budburst (TF), rate of vigorous budburst (TBV) and average time for appereance of opened leaves (TMFA). The more intense dormancy occured on July, 12. The chill treatment with 1,440 hours (4 to 7° C) was effective in reducing the average time for budburst. The use of TBV in single node cuttings test was an important method to evaluate the real capacity of bud development, reducing the interference of cut like an initial development estimulator.

Keywords : Malus domestica Borkh; budburst; ecophysiology; endodormancy.