Effects of autumn on the induction of dormancy in apple and peach seedlings and their subsequent regrowth in spring

Abstract

Apple and peach seedlings were grown for 8 weeks under various regimes: two photoperiods (16 and 8 hr), two air temperatures (12.8° and 18.3°C) and three root temperatures (12.8°, 18.3° and 23.9°C). After the leaves were removed the seedlings were chilled in the dark at 5.6° for three periods (apples 750, 1500 and 2500 hr; peaches 750, 1500 and 2000 hr) and then grown in a glasshouse for 7 weeks during which bud break and extension growth were measured. Growth of apple seedlings (cv. Granny Smith) stopped in an air temperature of 12.8� irrespective of photoperiod and root temperature. At 18.3° growth continued, but was retarded by short days and a root temperature of 12.8°. Peach seedlings (cv. Elberta) did not grow after any of the treatments. Extension growth and bud break in both species increased with increased hours of chilling. Pre-dormancy factors had no effect on bud break in apples, but low air temperature and short days prior to chilling increased bud break in peaches, although the effects decreased as chilling increased. Low pre-dormancy air temperature increased the growth of both species after chilling. Photoperiod produced opposite effects in the two species. Thus short days increased the growth of peaches while long days were effective with apples. Apples grew best at a root temperature of 12.8°, and peaches grew better at this temperature than at 18.3° but not as well as at 23.9°.

Chilling Requirements and Blooming Dates of Leading Peach Cultivars and a Promising Early Maturing Peach Selection, Momo Tsukuba 127

“…It has been reported that warm periods during pre-chilling result in reduced bud break in peaches (Nichols et al, 1974) and that extended chilling results in reductions in the heat requirements of peach buds (Citadin et al, 2001;Scalabrelli and Couvillon, 1986). Furthermore, in our experiment there was signif- Table 4.…”

“…The data obtained in this experiment were likely to be affected by many environmental factors at each location and during each season. For example, it has been reported that bud break of peach and nectarine may be influenced by photoperiod (Nichols et al, 1974) and water conditions (Gilreath and Buchanan, 1981a) as well as temperature. It is also possible that the high RMSE values were affected by differences in temperature between the research locations and their neighboring AMeDAS observatories.…”

The Dormancy Status of Apple Buds as Determined by an In Vitro Culture System1

“…Chilling intact 'Delicious' trees 6 and 8 weeks before bud explants were taken resulted in greater bud burst than the longer chilling periods of 14 and 21 weeks. In contrast, other workers (10,14) have reported that 14 weeks chilling was more effective than shorter chilling periods for promoting growth of buds on intact trees of other cultivars. Why bud burst declined with longer chilling periods in the present experiments with 'Delicious' is not clear.…”

Efeito da aplicação de baixa temperatura em plantas de macieira sobre o crescimento durante a aclimatização

“…O efeito das baixas temperaturas por um período mais prolongado (2.500 horas) já havia sido revelado por Nichols et al (1974), ocasionando maior brotação e crescimento das mudas de macieira da cultivar Granny Smith. Ribas & Zanette (1992) também observaram os efeitos positivos das baixas temperaturas sobre o crescimento de mudas de macieira durante a aclimatização.…”