Prohexadione-Calcium Controls Vegetative Shoot Growth in Apple

2002 ◽  
Vol 3 (1) ◽  
pp. 11-28 ◽  
Author(s):  
Stephen S. Miller
Keyword(s):  
Shoot Growth ◽  
Vegetative Shoot ◽  
Prohexadione Calcium

Shoot growth control of pear trees (Pyrus communis L.) with prohexadione-calcium

2005 ◽  
Vol 106 (4) ◽  
pp. 515-529 ◽  
Author(s):  
M. Smit ◽  
J.J. Meintjes ◽  
G. Jacobs ◽  
P.J.C. Stassen ◽  
K.I. Theron
Keyword(s):  
Shoot Growth ◽  
Growth Control ◽  
Pyrus Communis ◽  
Pyrus Communis L ◽  
Pear Trees ◽  
Prohexadione Calcium

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 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.

scholarly journals USE OF CRYOPROTECTANTS FOR FROST PROTECTION IN PEACHES

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 486c-486
Author(s):  
Gregory L. Reighard ◽  
William C. Newall ◽  
Charles J. Graham
Keyword(s):  
South Carolina ◽  
Shoot Growth ◽  
Fruit Trees ◽  
Fruit Tree ◽  
Freezing Injury ◽  
Vegetative Shoot ◽  
Flower Bud ◽  
Cold Temperatures ◽  
Red Color ◽  
Deciduous Fruit

Late spring freezes often result in significant flower bud kill in deciduous fruit trees. Some products have been marketed as frost protectant compounds which purportedly protect flower stigmas and ovaries from freezing injury and death. Two of these compounds, Frost Free and Frostgard, were tested at two locations in South Carolina over three years. Varieties `Junegold', `Loring', `Redhaven', and `Jefferson' were treated with Frost Free (FF) in years 1988-1990 and with Frostgard (FG) in 1990. Significant differences in fruit yield and vegetative growth occurred during this period, but no consistent trends were evident. In 1989, FF-treated `Redhaven' and `Jefferson' trees averaged 10.5 and 21.8 kg more fruit/tree than the controls. However, no lethal cold temperatures occurred during the bloom period. In 1990, FG-treated `Redhaven' trees averaged 8.0 kg more fruit/tree than the control trees. The fruit from FF-treated trees were lower in Brix, had less red color, and vegetative shoot growth was slightly greater than that of the FG and check trees. These data suggest that Frost Free may have plant growth regulator properties.

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.

scholarly journals Management of Fire Blight Using Pre-bloom Application of Prohexadione-Calcium

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1048-1054
Author(s):  
Anna E. Wallis ◽  
Kerik D. Cox
Keyword(s):  
New York ◽  
Tree Growth ◽  
Cell Walls ◽  
Fire Blight ◽  
Shoot Growth ◽  
New York State ◽  
Bacterial Disease ◽  
Cortical Parenchyma ◽  
Shoot Blight ◽  
Prohexadione Calcium

Fire blight, a bacterial disease of rosaceous plants caused by Erwinia amylovora, is one of the most important diseases affecting commercial apple production worldwide. Antibiotics, applied at bloom to protect against blossom infection, are the most effective means of management but raise concern due to the potential for antibiotic resistance in both the pathogen population and nontarget organisms. In addition, most fire blight outbreaks in New York State often emerge in late June to July as shoot blight, calling into question the role of blossom infections and the antibiotic applications made to manage them. Prohexadione-calcium (PhCa) is a gibberellic acid inhibitor used post-bloom to control shoot vigor and to manage shoot blight. However, the magnitude of shoot blight management is directly related to the suppression of shoot growth, which is undesirable, especially in young orchards during establishment years. PhCa is believed to control shoot blight by thickening cell walls in cortical parenchyma, preventing invasion of host tissues by E. amylovora. We hypothesize that PhCa applied pre-bloom could similarly prevent invasion of blossom pedicels following infection, leading to reduced disease incidence. We evaluated novel pre-bloom PhCa programs for their effects on disease management (blossom and shoot blight) as well as their impact on shoot growth for three years in a mature ‘Gala’ orchard in New York. In all three years of the study, all PhCa programs resulted in less than 27% incidence (71% control) of blossom blight and less than 13% incidence (77% control) of shoot blight with minimal effect on tree growth. Inclusion of a biopesticide during bloom further reduced the incidence of blossom blight in one year of three. Using light microscopy, we found that cell walls in the cortical parenchyma of fruitlet pedicels on trees receiving pre-bloom PhCa applications were significantly thicker than those of untreated trees 40 days after full bloom and inoculation. Overall, we found that pre-bloom applications of PhCa had utility in reducing blossom blight and shoot blight with minimal impacts on tree growth. These pre-bloom programs would fit with standard production practices and may contribute toward the development of fire blight management programs without the use of antibiotics.

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.

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