scholarly journals Controlling Floral Initiation and Vegetative Growth of Apple with Prohexadione Calcium (BAS-125W), an Experimental GA-biosynthesis Inhibitor

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 557E-558 ◽  
Author(s):  
Christopher L. Owens ◽  
Eddie W. Stover
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Tree Size ◽  
Floral Initiation ◽  
Biosynthesis Inhibitor ◽  
Nursery Stock ◽  
Bud Set ◽  
Terminal Bud ◽  
Prohexadione Calcium ◽  
Ga Biosynthesis

Early fruit production and control of tree size are important factors in the economic viability of high-density apple orchards. A horticultural tool permitting growers to induce terminal budset should provide greater control over the balance between vegetative growth and reproduction, increasing orchard production and profitability. With this goal, the experimental GA-biosynthesis inhibitor, BAS-125W, is being evaluated for effects on enhancing floral initiation and controlling tree size in young orchards. In nursery stock, the effect of inducing earlier terminal budset is also being studied for influence on storage carbohydrates and performance after planting. Studies in 1996 showed that 250 ppm BAS-125W induced terminal bud set on actively growing second-leaf `Macoun', `Delicious', and `Fuji' trees. Seven application dates from 17 June to 9 Sept. were compared to determine how time of treatment would effect degree and distribution of flowering the following year. Terminal budset typically occurred 2 weeks after application, with shoot growth resuming in 4 to 5 weeks. At two dates, treatment of growing tips only was compared with entire tree application to distinguish the direct effect of GA-inhibition on floral initiation from the effect of redistributing photosynthate. Treatment from 17 June to 29 July significantly reduced total annual shoot growth compared to the untreated controls, while later treatments had no significant effect on shoot length. Treatments of nursery stock with BAS-125W on 1 Sept. accelerated terminal bud set by at least 7 days compared to untreated controls of both `Fuji' and `Golden Delicious'. Effects of treatments on flowering and tree growth in 1997 will be discussed.

Performance of prohexadione-calcium on shoot growth and fruit quality of apple — Effect of spray surfactants

2008 ◽  
Vol 88 (1) ◽  
pp. 165-174 ◽  
Author(s):  
J. A. Cline ◽  
C. G. Embree ◽  
J. Hebb ◽  
D. S. Nichols
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Management Practice ◽  
Fruit Size ◽  
Growth Control ◽  
Growth And Yield ◽  
Control Treatment ◽  
Royal Court ◽  
The Us ◽  
Prohexadione Calcium

Vegetative growth control of apples (Malus × domestica Borkh.) is necessary to maintain a balance between growth and cropping. Pruning is a labour-intensive management practice to achieve this and intrinsically stimulates new growth. Prohexadione-calcium (PC) is a plant bio-regulator that effectively regulat es the shoot extension growth of apples and other tree fruits. Previous research has demonstrated that its efficacy can vary based on the use of spray surfactants and adjuvants. This study investigated the efficacy of two rates of Apogee™, the commercial form of PC, used in combination with the spray surfactants Sylgard 309 and LI 700, on extension shoot growth and yield parameters. Experiments were conducted in Ontario on Empire and Nova Scotia on Royal Court™ Cortland apples. Treatments of 0, 75 or 125 mg L-1 PC, with and without either 0.5% (vol/vol.) LI 700 surfactant or 0.05% (vol/vol) Sylgard 309 surfactant were applied to Empire trees, and 75 or 125 mg L-1 PC, with or without 0.5% (vol/vol) LI 700, were applied to Royal Court™ trees. An untreated control treatment was also included for comparison purposes. A total of two sprays were applied to the Empire trees and a total of three sprays were applied to the Royal Court™ trees. PC significantly decreased the vegetative growth of Empire and Royal Court™ trees by approximately 18 to 44%, respectively, and the efficacy of PC was enhanced when combined with either Sylgard 309 or LI 700 surfactant. No additional benefit in vegetative growth control was gained when using Apogee™ at rates of 125 mg L-1 PC, relative to 75 mg L-1 PC. The rate of Apogee™ did not influence the number of fruit or yield per tree or mean fruit size of either cultivar. For Empire, LI 700 and Sylgard 309 significantly reduced the number of fruit per tree, resulting in lower yields and crop densities. In addition, higher mean fruit weights, and a greater distribution of fruit in the larger size categories were observed for LI 700. Fruit from Royal Court trees treated with the highest rate of Apogee™ had higher crop densities, poorer coloured fruit, and a higher percentage of fruit less than 60 mm in diameter. These data provide support for the use of alternative surfactants with Apogee™ other than those listed on the US and Canadian product labels. Key words: Apogee™, Empire, Cortland, Regalis, calcium 3-oxido-5-oxo-4-propionylcyclohex-3-enecarboxylate, surfactant

scholarly journals Vegetative Response of Vitis vinifera to Prohexadione-calcium

HortScience ◽  
2003 ◽  
Vol 38 (7) ◽  
pp. 1435-1438 ◽  
Author(s):  
Danielle Lo Giudice ◽  
Tony K. Wolf ◽  
Richard P. Marini
Keyword(s):  
Vitis Vinifera ◽  
Crop Yield ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Field Experiments ◽  
Field Conditions ◽  
Cabernet Sauvignon ◽  
Cabernet Franc ◽  
Primary Shoot ◽  
Prohexadione Calcium

Prohexadione-calcium (prohexadione-Ca) was evaluated for its ability to suppress vegetative growth of grapevines (Vitis vinifera L.) under field conditions. Two or three applications of 250 mg·L-1 prohexadione-Ca reduced primary shoot growth of `Cabernet Sauvignon', but had little effect on other canopy characteristics or cane pruning weights. The reduction of shoot growth was not persistent and shoot hedging was ultimately needed to avoid canopy shading. Similarly, three applications of either 125, 250, or 375 mg·L-1 prohexadione-Ca reduced `Cabernet franc' shoot growth, but again did not eliminate the need for shoot hedging. Cane pruning weights of `Cabernet franc' were unaffected by treatment, and canopy characteristics were generally not improved. Two prebloom and one postbloom application of 250 mg·L-1 prohexadione-Ca were evaluated on `Cabernet franc' and `Chardonnay' in separate field experiments. The prebloom treatments retarded shoot growth of `Chardonnay', but had no effects on `Cabernet franc' shoot characteristics. To retard shoot growth, prohexadione-Ca had to be applied prior to bloom; however, prebloom applications had the potential for severe reductions in crop yield.

The Influence of Drought on Growth and Gas Exchange in Fraxinus species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 539c-539
Author(s):  
R.E. Schutzki ◽  
R.T. Fernandez
Keyword(s):  
Shoot Growth ◽  
Dry Weight ◽  
Green Ash ◽  
Leaf Photosynthesis ◽  
Active Growth ◽  
Leaf Emergence ◽  
Randomized Design ◽  
Bud Set ◽  
Terminal Bud ◽  
Completely Randomized Design

Fraxinus americana, F. pennsylvanica, and F. nigra were subjected to short-term drought of 4, 8, and 16 days. Seedlings were obtained from a commerical nursery and grown in 4:1 pine bark:sand media for 3 months prior to the onset of the stress. Seventy-two trees with six replicates per stress treatment were arranged in a completely randomized design. Following each stress period, the appropriate trees were well watering and monitored through recovery. Leaf photosynthesis, shoot growth, leaf emergence, terminal bud set, trunk caliper and soil moisture content were measured through the stress and recovery periods. Drought suppressed shoot growth and leaf emergence in all species; however, Green Ash maintain active growth at higher rates than either White or Black. Leaf photosynthesis was reduced in both White and Black following 4 days of drought whereas Green ash was not adversely effected until day 10. Trees were harvested following recovery and dry weight fractions of leaves, stems, and roots recorded.

Managing Vegetative Growth of Apples with Prohexadione Calcium can Influence Mid-season Spray Coverage

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 451f-452
Author(s):  
J.R. Evans ◽  
J.A. Balles ◽  
L.H. Bennett ◽  
B.A. Brinkman ◽  
A.H. Harrell ◽  
...  
Keyword(s):  
Vegetative Growth ◽  
Plant Growth Regulator ◽  
Shoot Growth ◽  
Crop Protection ◽  
Shoot Length ◽  
Tree Canopy ◽  
Apple Trees ◽  
Air Blast ◽  
Previously Treated ◽  
Prohexadione Calcium

Prohexadione calcium (BAS 125W or Apogee™) is a plant growth regulator being developed to control vegetative growth in apples. Prohexadione calcium acts within a plant by blocking the biosynthesis of growth-active gibberellin. The result is decreased cell elongation; thus, reduced shoot length. Applications of prohexadione calcium beginning when the apple trees have 2 to 15 cm of new shoot growth significantly reduce seasonal vegetative growth. Mid-season measurements of air blast spray coverage using water-sensitive cards show that trees previously treated with prohexadione calcium have greater spray coverage within the tree canopy than untreated trees. Hence, more efficient crop protection can be expected in apple trees treated with prohexadione calcium.

scholarly journals 225 Prohexadione-Ca: Reduction in Vegetative Growth and Pruning of Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 481A-481 ◽  
Author(s):  
J.R. Evans ◽  
J.A. Balles ◽  
B.A. Brinkman ◽  
V.E. Harris ◽  
J.D. Helm ◽  
...  
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Application Rate ◽  
Growth Reduction ◽  
Apple Trees ◽  
Positive Effects ◽  
Enhanced Resistance ◽  
Prohexadione Calcium ◽  
Made In

Prohexadione-Ca (BAS 12511W or Apogee™ Plant Growth Regulator) acts within a plant by blocking the biosynthesis of growth-active gibberellin. The result is decreased cell and shoot elongation; thus, vegetative growth in apple trees can be reduced. Air blast applications of prohexadione calcium were made in the Spring 1998 in commercial orchards. Application rate was 125 ppm a.i. applied twice beginning at 5 to 12 cm of new shoot growth. Reduction of shoot growth averaged 45% across locations. As a result of reduced vegetative growth, dormant pruning was reduced. In total, significant benefits to the grower included reduced pruning costs in addition to other positive effects such as improved light penetration and enhanced resistance to some pathogens. Research will continue with the effect of prohexadione-Ca on pruning in multiple year studies.

Effects of Nitrogen Cut-off Date in Combination with Urea or Abscisic Acid (ABA) on Terminal Bud Set, Defoliation, Cold Acclimation, and Reserve Nitrogen in `Gala' Apple Nursery Stock

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 548f-549
Author(s):  
Sunghee Guak ◽  
Lailiang Cheng ◽  
Leslie H. Fuchigami
Keyword(s):  
Cold Acclimation ◽  
Cold Hardiness ◽  
Apple Trees ◽  
Total N ◽  
N Level ◽  
N Supply ◽  
Nursery Stock ◽  
Bud Set ◽  
Terminal Bud ◽  
Foliar Urea

Bench-grafted `Gala'/M26 apple trees were grown in pots and fertigated weekly with 150 ppm N starting from 10 May. N supply was terminated on 21 Aug., 18 Sept., and 9 Oct. for the early, mid, and late N cut-off treatment, respectively. Half of the trees in the early N cut-off treatment were sprayed twice with 3% urea at 6-day intervals in early October. Half of the trees in the mid and late N cut-off treatment were sprayed twice with 1000 ppm ABA at 5-day intervals in early and mid-October, respectively. Early N cut-off significantly enhanced terminal bud set, defoliation, and induction of cold acclimation compared to the late N cut-off. Foliar urea increased the reserve N level in all tissues of the early N cut-off trees, almost to the level of late N cut-off trees. Soluble protein concentrations were increased by foliar urea, which accounted for about 23%, 10%, and 17% of the increase in the total N concentration in bark, wood, and roots, respectively. ABA treatment enhanced leaf senescence and N mobilization in the mid and late N cut-off trees, but did not affect terminal bud set and cold hardiness.

Effect of daylength and temperature on flowering of the cut flower species Banksia coccinea and Banksia hookeriana

1996 ◽  
Vol 36 (6) ◽  
pp. 747 ◽  
Author(s):  
MA Rieger ◽  
M Sedgley
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Controlled Environment ◽  
Floral Initiation ◽  
Cut Flower

Vegetative growth and flowering of Banksia coccinea and B. hookeriana were investigated under controlled environment conditions of 8 and 16 h daylength at 15/10 and 25/20�C (day/night). All treatments stimulated vegetative growth of B. coccinea but the 16 h, 25/20�C treatment resulted in greatest shoot growth and highest floral initiation. Only the 8 and 16 h daylength treatments at 25/20�C stimulated vegetative growth, shoot extention and floral initiation of B. hookeriana. Comparable results for floral initiation and vegetative growth were observed with plants under outside conditions. The results indicate that vegetative growth is a prerequisite for floral initiation. Floral initiation of B. coccinea was influenced by daylength whereas B. hookeriana responded to temperature.

scholarly journals Prohexadione calcium on shoot growth of 'Starkrimson' pear trees

2017 ◽  
Vol 52 (2) ◽  
pp. 75-83 ◽  
Author(s):  
Mateus da Silveira Pasa ◽  
Todd Einhorn
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Block Design ◽  
Fruit Size ◽  
Internode Length ◽  
Soluble Solids ◽  
Cross Sectional ◽  
Growing Seasons ◽  
Return Bloom ◽  
Prohexadione Calcium

Abstract: The objective of this work was to evaluate the fruiting and vegetative growth of 'Starkrimson' pear in response to the application of prohexadione calcium (P-Ca). P-Ca (250 mg L-1) was sprayed to scaffold limbs and to whole trees in commercial orchards. A randomized complete block design was used to minimize declivity effects. Vegetative growth (length and number of shoots, increment in limb and trunk cross-sectional area, number of nodes, and internode length), production (fruit number, yield, yield efficiency, and fruit size), and return bloom were evaluated from 2010 to 2013. P-Ca efficiently controlled shoot growth in all growing seasons, when applied early in the season, due to the reduction in internode length. Production was not negatively affected by the application of P-Ca in all years and at both sites, and fruit size and return bloom were not reduced. Fruit quality attributes were also little affected by P-Ca, except for total soluble solids content, which was lower than that of the control. This shows that P-Ca is efficient to manage tree vigor in high-density 'Starkrimson' pear orchards.

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