Effects of dormancy factors on the growth of vegetative buds of young apple trees

1975 ◽  
Vol 26 (6) ◽  
pp. 989 ◽  
Author(s):  
WK Thompson ◽  
DL Jones ◽  
DG Nichols
Keyword(s):  
High Temperature ◽  
Temperature Effects ◽  
Extension Growth ◽  
Bud Break ◽  
Chilling Temperature ◽  
Subsequent Growth ◽  
Apple Trees ◽  
Dormant Period ◽  
Vegetative Buds ◽  
Young Apple

Controlled temperature conditions were used to investigate the chilling requirements of potted 1-year-old apple trees cv. Jonathan. The rate of bud break, the number of buds growing and extension growth were increased by prior chilling. Temperature effects over the range 2–10°C were greatest at the lower end of the range. Chilling early in the dormant period was less effective than later chilling, and interruption of chilling with periods of high temperature reduced subsequent growth.

scholarly journals Temperature Effects on Dormancy Completion of Vegetative Buds in Apple

2003 ◽  
Vol 128 (5) ◽  
pp. 636-641 ◽  
Author(s):  
Amos Naor ◽  
Moshe Flaishman ◽  
Raphael Stern ◽  
Aharon Moshe ◽  
Amnon Erez
Keyword(s):  
High Temperature ◽  
Dominance Effect ◽  
Chilling Temperature ◽  
Flower Buds ◽  
Diurnal Cycles ◽  
Relative Contribution ◽  
Vegetative Buds ◽  
Lateral Buds ◽  
Different Temperatures ◽  
Chilling Hours

The relative contribution of various temperatures to dormancy completion of lateral vegetative apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] buds was studied quantitatively on whole container-grown trees. Trees were exposed continuously to 10 different temperatures and also to daily alternating temperatures in a 24-hour cycle. In addition, fully chilled vertically and horizontally positioned shoots were compared under forcing conditions. No budbreak occurred in shoots chilled above 12.5 °C. There was a steep increase in budbreak as the chilling temperature fell from 12.5 to 7.5 °C. There was little difference in the level of budbreak on shoots chilled between 7.5 and 0 °C. The relative contribution of temperature to chilling accumulation in apple found in our study differs from what has been proposed for stone fruit and for apple in previous studies, especially at temperatures <6 °C. The length of exposure to forcing conditions required to initiate budbreak diminished as the chilling temperature was reduced. No additional bud-break was apparent on shoots chilled longer than 2100 chilling hours. The chilling requirement found here for lateral vegetative buds is much higher than that needed for terminal vegetative and flower buds. Trees that were exposed to daily alternating temperatures had lower levels of budbreak when the high temperature in the diurnal cycle was greater than 14 °C. Practically no budbreak was apparent on trees that were exposed to diurnal cycles with a high temperature of 20 °C for 8 hours. Budbreak on horizontally positioned trees was more than twice that on the vertically positioned trees, emphasizing the magnitude of the apical dominance effect and its strong masking of the chilling effect on lateral buds in vertically grown apple trees. Based on the data collected here we propose a new response curve for vegetative budbreak in `Golden Delicious·apple, within a temperature range between 0 to 15 °C.

scholarly journals Timing of High Temperature Influences Chilling Negation in Dormant Apple Trees

1992 ◽  
Vol 117 (2) ◽  
pp. 271-273 ◽  
Author(s):  
Eric Young
Keyword(s):  
High Temperature ◽  
Shoot Growth ◽  
Extension Growth ◽  
Apple Trees ◽  
The Third ◽  
Root And Shoot Growth ◽  
Negative Effect ◽  
Chilling Period ◽  
Positive Effect

Budbreak and root and shoot extension growth of apple trees (Malus domestics Borkh. MM.111) were affected by exposure to 500 hours of higher temperatures (15, 20, or 30C) during the first, second, or third 500 hours of a 1500-hour, 5C chilling period. Exposure to 15C during the third 500 hours had a significantly positive effect on budbreak, 20C at this time had no effect, and all other treatments had a negative effect on budbreak and new root and shoot growth.

scholarly journals NOTCHING TECHNIQUES TO INCREASE BRANCHING OF YOUNG APPLE TREES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1109G-1109
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio
Keyword(s):  
Shoot Growth ◽  
Bud Break ◽  
Apple Trees ◽  
Lateral Branching ◽  
Series Of Experiments ◽  
Young Apple

A series of experiments were initiated to evaluate the influence of notching on improving lateral branching of young apple trees. Buds on 2-year-old wood of `Redspur' Delicious/MM.111 were notched at 2-week intervals from 6 weeks before bloom to 2 weeks after. Notching increased lateral branching cubically with the greatest response occurring when notching was done 2 to 4 weeks before bloom. Bud break occurred equally well and shoots grew comparably when `Redcort'/M.7 were notched at the tip, middle, or base. Bud break and shoot growth from unnotched buds was greatest at the tip, intermediate in the middle and least at the base. Limbs of `Spygold'/M.7 were spread to a 45 degree angle then one bud from each l-year-old shoot was notched at either the top, side or on the bottom of the shoot. Notching increased lateral branching from all bud positions, but the greatest response was from buds notched at the top and least from those located at the bottom of a branch. Buds of `Marshall McIntosh' were notched on either 1 or 2-year-old wood. Notching increased lateral branching more on 2-year than on 1-year old wood.

scholarly journals NOTCHING TECHNIQUES TO INCREASE BRANCHING OF YOUNG APPLE TREES

HortScience ◽  
1990 ◽  
Vol 25 (6) ◽  
pp. 624e-624
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio
Keyword(s):  
Shoot Growth ◽  
Bud Break ◽  
Apple Trees ◽  
Lateral Branching ◽  
Series Of Experiments ◽  
Young Apple

A series of experiments were initiated to evaluate the influence of notching on improving lateral branching of young apple trees. Buds on 2-year-old wood of `Redspur' Delicious/MM.111 were notched at 2-week intervals from 6 weeks before bloom to 2 weeks after. Notching increased lateral branching cubically with the greatest response occurring when notching was done 2 to 4 weeks before bloom. Bud break occurred equally well and shoots grew comparably when `Redcort'/M.7 were notched at the tip, middle, or base. Bud break and shoot growth from unnotched buds was greatest at the tip, intermediate in the middle and least at the base. Limbs of `Spygold'/M.7 were spread to a 45 degree angle then one bud from each 1-year-old shoot was notched at either the top, side or on the bottom of the shoot. Notching increased lateral branching from all bud positions, but the greatest response was from buds notched at the top and least from those located at the bottom of a branch. Buds of `Marshall McIntosh' were notched on either 1 or 2-year-old wood. Notching increased lateral branching more on 2-year than on 1-year old wood.

Effects of succinic acid-2,2-dimethyl hydrazide (Alar) or scoring on growth and flower initiation of young apple trees

1972 ◽  
Vol 12 (54) ◽  
pp. 89 ◽  
Author(s):  
N Veinbrants
Keyword(s):  
Succinic Acid ◽  
Growth Retardant ◽  
Extension Growth ◽  
Flower Initiation ◽  
Apple Trees ◽  
Foliar Sprays ◽  
Young Apple

Foliar sprays of the growth retardant succinic acid-2,2-dimethyl hydrazide (Alar) applied early in the spring on young non-bearing Delicious, Granny Smith, and Gravenstein apple trees reduced the extension growth and increased the amount of bloom in the following spring. Scoring (a knife cut completely around the trunk) in late October and during November on Granny Smith, and Gravenstein trees increased the amount of bloom in the following year. When scoring has performed in early December the response to flowering on Gravenstein variety was greatly reduced. Scoring reduced the extension growth on Granny Smith but not on Gravenstein variety. The use of either Alar or scoring offer practical ways of promoting earlier flowering and cropping of young non-bearing apple trees.

scholarly journals NOTCHING TECHNIQUES TO INCREASE BRANCHING OF YOUNG APPLE TREES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1109g-1109
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio
Keyword(s):  
Shoot Growth ◽  
Bud Break ◽  
Apple Trees ◽  
Lateral Branching ◽  
Series Of Experiments ◽  
Young Apple

A series of experiments were initiated to evaluate the influence of notching on improving lateral branching of young apple trees. Buds on 2-year-old wood of `Redspur' Delicious/MM.111 were notched at 2-week intervals from 6 weeks before bloom to 2 weeks after. Notching increased lateral branching cubically with the greatest response occurring when notching was done 2 to 4 weeks before bloom. Bud break occurred equally well and shoots grew comparably when `Redcort'/M.7 were notched at the tip, middle, or base. Bud break and shoot growth from unnotched buds was greatest at the tip, intermediate in the middle and least at the base. Limbs of `Spygold'/M.7 were spread to a 45 degree angle then one bud from each l-year-old shoot was notched at either the top, side or on the bottom of the shoot. Notching increased lateral branching from all bud positions, but the greatest response was from buds notched at the top and least from those located at the bottom of a branch. Buds of `Marshall McIntosh' were notched on either 1 or 2-year-old wood. Notching increased lateral branching more on 2-year than on 1-year old wood.

scholarly journals Environmental effects on photosynthetic capacity of bean genotypes

2004 ◽  
Vol 39 (7) ◽  
pp. 615-623 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Mauro Guida dos Santos ◽  
Gustavo Maia Souza ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira ◽  
...  
Keyword(s):  
High Temperature ◽  
Natural Condition ◽  
Temperature Effects ◽  
Environmental Changes ◽  
Photosynthetic Capacity ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Fluorescence Yield ◽  
Environmental Condition ◽  
Response Curves

Photosynthetic responses to daily environmental changes were studied in bean (Phaseolus vulgaris L.) genotypes 'Carioca', 'Ouro Negro', and Guarumbé. Light response curves of CO2 assimilation and stomatal conductance (g s) were also evaluated under controlled (optimum) environmental condition. Under this condition, CO2 assimilation of 'Carioca' was not saturated at 2,000 µmol m-2 s-1, whereas Guarumbé and 'Ouro Negro' exhibited different levels of light saturation. All genotypes showed dynamic photoinhibition and reversible increase in the minimum chlorophyll fluorescence yield under natural condition, as well as lower photosynthetic capacity when compared with optimum environmental condition. Since differences in g s were not observed between natural and controlled conditions for Guarumbé and 'Ouro Negro', the lower photosynthetic capacity of these genotypes under natural condition seems to be caused by high temperature effects on biochemical reactions, as suggested by increased alternative electron sinks. The highest g s values of 'Carioca' were observed at controlled condition, providing evidences that reduction of photosynthetic capacity at natural condition was due to low g s in addition to the high temperature effects on the photosynthetic apparatus. 'Carioca' exhibited the highest photosynthetic rates under optimum environmental condition, and was more affected by daily changes of air temperature and leaf-to-air vapor pressure difference.

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