Avaliação Fenológica Das Diferentes Estruturas De Frutificação Das Macieiras 'Gala' E 'Fuji' Na Região De Caçador-Sc

Abstract

PHenologicAl evAluAtion of different fruiting HAbits of 'gAlA' And 'fuJi' APPles in tHe soutHern brAZilAbstrAct -Apple shows two distinct phases that characterizes its annual cycle: dormancy and vegetative/ reproductive growth. The importance of knowing the influence of climate conditions on tree reproductive processes and furthermore, developing technologies that minimize the future effects increases upon the global warming predictions becomes concerning. The goal of this study was to characterize the behavior of the main phenological events of apple, from bud break to harvest, on different fruiting habits under the subtropical climatic conditions of the South of Brazil. The experiments were carried out on nine year old 'Gala' and 'Fuji' apples in the Experimental Station of EPAGRI (Brazil -26°50'S, 50°58'W, altitude 950m) during two different growing seasons, 2011/12 and 2013/14. Date and days after dormancy breaking treatment and heat requirements of the main phenological stages from bud break to harvest were evaluated. Evaluations were performed on each fruiting habit: spur buds, terminal and axillary buds on long shoots. Differences found on the onset of bud break and flowering among fruiting habits greatly depended on climate conditions of the particular year. High temperatures conditions after the dormancy breaking treatment induced to a phenological synchrony among fruiting habits, and vice versa. From dormancy breaking treatment, spur buds, especially 'Gala' buds, required less heat accumulation to bud break. Terminal buds of long shoots required higher amount of heat than spur buds to start flowering. index terms: Malus domestica Borkh., degree-days, bud break, flowering.

Thidiazuron with Mineral Oil as Alternative Bud Break Promoter for Apple Trees

“…Petri et al [7] observed that bud break promoters mixed with MO advanced apple tree flowering. There were small variations in the number of days from the beginning to the end of flowering between the years studied and these differences found in the beginning of sprouting and flowering depended on the climatic conditions of the year, and the variation in the number of cold units that occurs in winter, influences the flowering period [16]. However, the control treatment always had a longer flowering period.…”

“…Usually the terminal buds, as they are floriferous, sprout more than the axillary buds, due to t requirement and apical dominance [19]. According to Francescatto et al [16], the lack of axillary bud break favors the terminal bud break and compromises the formation of reproductive organs, favoring excessive vegetative development.…”

“…According to Francescatto et al [16], the lack of axillary bud break favors the terminal bud break and compromises the formation of reproductive organs, favoring excessive vegetative…”

Plant Growth Regulators in Flowering Alternation of the Fuji Suprema Apple Tree

“…In floral induction, hormonal exchanges occur that define whether the bud remains vegetative or become a flower bud for the next cycle, all commanded by genes. In apple trees, this process usually occurs 6 to 8 weeks after full bloom, but in subtropical climate conditions, it can continue until post-harvest, mainly in axillary buds, although the greatest intensity is in this period [2]. Also, several factors can influence floral induction, such as plant management and environmental factors.…”

“…The floral differentiation is often associated with the stoppage of the growth of the shoot buds. In mild winter conditions and where there is no water deficit, in general, spur buds stop growth two to four weeks after flowering, while long shoot buds depend on plant and environmental conditions and often extend to post-harvest [2]. Considering the vegetative growth antagonistic to the formation of flower buds, however, it does not necessarily occur in all cultivars.…”