Seasonal changes in cold hardiness, sucrose and sorbitol in apple trees treated with plant growth regulators

1992 ◽  
Vol 67 (3) ◽  
pp. 429-435 ◽  
Author(s):  
W. K. Coleman ◽  
E. N. Estabrooks ◽  
M. O’hara ◽  
J. Embleton ◽  
R. R. King
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Seasonal Changes ◽  
Cold Hardiness ◽  
Apple Trees

AN EVALUATION OF THE EFFECT OF PLANT GROWTH REGULATORS ON COLD HARDINESS IN APPLE TREES

1988 ◽  
Vol 68 (3) ◽  
pp. 859-869
Author(s):  
WARREN K. COLEMAN ◽  
EVANS N. ESTABROOKS
Keyword(s):  
Low Temperature ◽  
Plant Growth ◽  
Multiple Regression ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Cold Hardiness ◽  
Apple Trees ◽  
Independent Variables ◽  
Air Temperatures ◽  
Vapor Gard

Two-year-old apple trees (cv. Spur Mac/M.106) were treated once during September 1985 and again in 1986 with the plant growth regulators thidiazuron and EL-500® in the presence or absence of the antitranspirant Vapor Gard®. Seasonal changes in the low temperature exotherms of twig samples, percent moisture, relative dormancy intensity, percent injury levels at stress temperatures of −15, −25 and −35 °C and daily maximum/minimum air temperatures were recorded. On a seasonal basis during the 1986–1987 season, the hardiness level of the trees increased until mid-February and then decreased regardless of treatment. During the acclimation period of September 1986 to mid-February 1987, a significant multiple regression equation was obtained between percent injury at a stress temperature of −35 °C and the following independent variables: percent shoot moisture, previous mean maximum and mean minimum air temperatures. During the deacclimation period of late February to May 1987, a significant regression equation was obtained between percent injury at a stress temperature of −35 °C and the independent variables, percent shoot moisture and previous mean maximum air temperatures. On a daily basis, fluctuating cold hardiness levels were correlated with prior chemical treatment, prior air temperatures, percent shoot moisture levels and low temperature exotherm. The pronounced fluctuations in percent injury at a stress temperature of −35 °C appeared to be primarily related to the previous mean maximum 3-d air temperatures when the multiple regression equations were examined for the major contributing variables. Thidiazuron in the presence or absence of Vapor Gard® was effective in increasing cold hardiness on a number of occasions and appears to warrant further evaluation.Key words: Malus × domestica, apple, cold hardiness, thidiazuron, EL-500®

Metamitron and Different Plant Growth Regulators Combinations in the Chemical Thinning of ‘Eva’ Apple Trees

2017 ◽  
Vol 18 (2) ◽  
pp. 1-6 ◽  
Author(s):  
Carolina Goulart ◽  
Suélen Andrade ◽  
Angelica Bender ◽  
Andressa Schiavon ◽  
Gabriel Aguiar ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Apple Trees

Seasonal Changes of Plant Growth Regulators in Corylus

1991 ◽  
Vol 138 (1) ◽  
pp. 29-32 ◽  
Author(s):  
Ana RodríGuez ◽  
María JesúS CañAl ◽  
Ricardo SáNchez-TaméS
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Seasonal Changes

scholarly journals Enhancing Branching of Apple Trees in the Nursery with Plant Growth Regulators

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 842D-842 ◽  
Author(s):  
Tadeusz Jacyna
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Pattern ◽  
Tree Height ◽  
Shoot Formation ◽  
Apple Trees ◽  
Lateral Shoot ◽  
Shoot Production ◽  
Nursery Trees

Nursery trees of new, promising apple selections [NY-75334-35 (A), NY-75414-1 (B), and NY-75413-30 (C)] from the Geneva breeding program exhibit a distinct apical dominant growth pattern characterized by poor lateral-shoot formation (feathering). To induce feathering, the trees were foliar-treated singly or sequentially with various concentrations of Promalin (1.8%w/w GA4+7 + 1.8%w/w 6BAP) and Accel (0.18% w/w GA4+7 + 1.8% w/w 6BAP), by themselves and in combination. Regardless of branching agent, concentration, and type of application, treated trees, as compared to the control, on average, induced 11.3 vs. 2.2, 6.6 vs. 0.4, and 6.6 vs. 2.0 feathers/tree for selections A, B, and C, respectively. In most instances, higher concentrations of both chemicals induced more feathers than lower concentrations. Tree height and caliper were less affected than lateral-shoot production.

Enhancement of cold hardiness in apple trees by paclobutrazol, thidiazuron and flurprimidol

1992 ◽  
Vol 72 (4) ◽  
pp. 1267-1274 ◽  
Author(s):  
W. K. Coleman ◽  
E. N. Estabrooks
Keyword(s):  
Growth Regulators ◽  
Seasonal Changes ◽  
Cold Hardiness ◽  
Multivariate Analyses ◽  
Apple Trees ◽  
Chemical Treatments ◽  
Test Stress

Two-year-old apple trees (cv. Spur McIntosh/MM.106) were treated once during September 1987 and again in September 1988 with the growth regulators paclobutrazol, thidiazuron or flurprimidol alone or in different combinations. Seasonal changes in electrolytic leakage at test stress temperatures of −15, −25 and −35 °C were recorded from October to May. During the 2-yr study, there was a well-defined acclimatization phase until early February followed by a deacclimatization phase during February–May. The treatment that produced greatest increases in apple twig hardiness was a mixture of paclobutrazol, thidiazuron and flurprimidol. In 93% of the test dates, this treatment gave a lower injury value than the control at the −25 °C stress temperature and 66% gave significantly (P < 0.05) lower injury levels. Chemical treatments increased the hardiness of apple wood throughout the fall, winter and spring periods without altering the pattern of seasonal changes in hardiness level. Multivariate analyses indicated that treated shoots were less sensitive than the controls to mild temperatures during the winter period.Key words: Apple, cold hardiness, growth regulators

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