scholarly journals A REVIEW OF METHODS TO CONTROL VEGETATIVE GROWTH OF APPLE TREES

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 482c-482
Author(s):  
Duane W. Greene

The trend toward planting high density apple orchards continues. Closer tree spacing requires a greater degree of growth control to reduce shading and to prevent the decline in fruit quality and productivity as the planting become older. Chemical, rootstock, pruning, and management techniques will be reviewed that may control growth directly by reducing vegetative growth or indirectly through effects on increasing flower bud formation and fruit set. Pruning and management techniques will be discussed that can selectively reduce vigor in the tops of trees while allowing growth of the less vigorous lower portion of a trees to continue.

1990 ◽  
Vol 115 (2) ◽  
pp. 212-218 ◽  
Author(s):  
D.C. Elfving ◽  
R.A. Cline

Beginning in 1982, daminozide (DZ) was applied annually for 5 years to whole, 5-year-old `Northern Spy'/MM.106 (Malus domestics Borkh.) trees: a) shortly after bloom, b) together with ethephon (ETH) 6 to 7 weeks after bloom, or c) after harvest. Controls were unsprayed. One-half of the trees receiving each growth regulator treatment were summer-pruned after terminal-bud formation each year. Postharvest DZ reduced shoot numbers, mean shoot length, trunk enlargement, and fruit size, but had little or no effect on bloom, fruit set, or yield. Postbloom DZ, summer DZ plus ETH, and summer-pruning reduced vegetative growth and time required for dormant-pruning, but only postbloom DZ and summer DZ plus ETH increased spur density in the tree. Postbloom DZ and summer DZ plus ETH increased both flowering and cropping in 3 of the 5 years, with little effect on fruit set. Fruit size was reduced only in years when cropping was enhanced. Total yields (1982-86) were increased 34% and 36% by postbloom DZ and summer DZ plus ETH, respectively. Summer-pruning had no effect on fruit size in any year, but reduced yields in 1984 and 1986. Year-to-year fluctuation in yield was unaffected by any treatment. Growth-control treatments had no direct effect on foliar or fruit macronutrient concentrations. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); 2-chloroethylphosphonic acid (ethephon).


2017 ◽  
Vol 25 (1) ◽  
pp. 47-54 ◽  
Author(s):  
A. Nilgün Atay ◽  
Fatma Koyuncu

Abstract Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis) on reproductive and vegetative growth, return bloom, fruit set, and also fruit quality in ‘Golden Delicious’ apple grafted on M.9 rootstock, an experiment was performed during 2010-2012. The applications of 125 mg dm-3 Pro-Ca on the same trees in each year resulted in a 40-43% shoot length reducing. Internodes length decreased with Pro-Ca at about 30%, while total node number was unaffected. Results indicate that Pro-Ca applications have no effects on tree trunk growth, flowering, yield, fruit set and development. Pro-Ca also didn’t have any negative impact on fruit quality during the three consecutive years. Moreover, Pro-Ca resulted in higher fruit size compared to control in the third year of trial. The results of this experiment clearly suggest that fruit growers can use Pro- Ca for the control of vegetative growth without having any negative effects on fruit quality and yield parameters. Once a full canopy has been achieved, annual shoot growth can be suppressed in the range of 20 to 30 cm with 125 mg dm-3 Pro-Ca treatment in ‘Golden Delicious’ apple trees.


HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 699-700 ◽  
Author(s):  
Steven J. McArtney ◽  
Shao-Hua Li

`Braeburn' apple trees were treated with GA3 or GA7 at either 100, 200, or 400 mg·L-1, 2 years after being grafted onto 4-year-old `Royal Gala'/MM.106 trees in order to evaluate their effects on flower bud formation. Inhibition of flowering was observed on 1-year wood only and not on spurs in response to GA treatments applied later than 6 weeks after bloom. GA7 was a more potent inhibitor of flowering than GA3. These results indicate that GA treatments may provide a useful technology for the selective removal of flowers from 1-year wood in apple and may also provide a useful tool for overcoming biennial bearing in apple by inhibiting flower bud formation when applied in the light-cropping year of the biennial cycle.


1961 ◽  
Vol 39 (7) ◽  
pp. 1733-1739 ◽  
Author(s):  
I. V. Hall ◽  
R. A. Ludwig

A study of the effect of environmental factors on the growth and development of the lowbush blueberry was carried out using clonally propagated plants. In a preliminary study a definite photoperiodic response was found. Under 8-hour days flower buds were formed and no vegetative growth occurred. Under 16-hour days vegetative growth resulted and no flower bud formation occurred. In a replicated greenhouse experiment, seven clones produced flower buds with 8-, 10-, and 12-hour days, but produced none with 14- or 16-hour days. One clone produced flower buds with 8-, 10,- 12-, and 14-, but none with 16-hour days. Two clones were able to produce flower buds under all five photoperiods. Under 8- and 10- hour photoperiods no vegetative growth occurred. Under 12, 14, and 16 hours progressively more vegetative growth occurred. In an experiment on the interaction of temperature and photoperiod, vegetative growth was significantly greater at 70° F than at 50° F with the differences being accentuated by day length. Flower bud formation occurred with 11- and 13-hour photoperiods regardless of temperature, but was more pronounced at the higher temperatures. At 70° F, 15-hour photoperiod, no flower buds were formed while at 50° F, 15 hours, three clones produced no flower buds and six clones produced an abnormal type of inflorescence. Similar abnormal inflorescences were produced by giving plants 2, 3, or 4 weeks of 8-hour days. Six weeks of 8-hour days was sufficient to initiate normal inflorescences. Shade, provided by two layers of cheesecloth, significantly reduced the number of flower buds compared with full sunlight. The growth of the lowbush blueberry under field and laboratory conditions is discussed in relation to environmental factors.


HortScience ◽  
1994 ◽  
Vol 29 (9) ◽  
pp. 997-998 ◽  
Author(s):  
K.D. Patten ◽  
J. Wang

Percentage of fruiting uprights, fruit set, number of fruit per upright, and flower bud formation of `McFarlin' and `Stevens' cranberries (Vaccinium macrocarpon Ait.) were reduced by removal of old leaves, new leaves, or both on the upright. Results varied slightly, based on which leaves were removed, time of removal, cultivar, year, and bog site. Percentage of fruiting uprights, flowers and fruit per upright, and fruit set were higher on uprights with a terminal bud size >1 mm in diameter in September than for those <1 mm in diameter. Effects were cultivar and site dependent. Terminal bud size of `McFarlin' was negatively related to the subtending number of fruit and positively related to leaf fresh weight of the upright.


HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1292-1295 ◽  
Author(s):  
Duane W. Greene

A range of concentrations and timings of CPPU application were evaluated in attempt to identify situations in which fruit size, flesh firmness, and soluble solids could be increased while minimizing increased incidence of fruit asymmetry and reductions in flower bud formation and fruit surface red color on 'McIntosh' apples (Malus×domestica Borkh.). The greatest response to CPPU for most attributes evaluated occurred when it was applied at fruit size between 6 mm and 16 mm. The conclusion from this series of experiments is that differential response to CPPU could not be established by altering the time of application. The response to CPPU is linear with increasing concentration. Results suggested that use of 4 to 6 mg·L-1 CPPU on apples to increase fruit size was the maximum and appropriate range to use without causing fruit asymmetry. Chemical name used: N-(2-chloro-4-pyridyl)-N′-phenyl urea (CPPU)


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