scholarly journals Prohexadione-calcium Decreases Fall Runners and Advances Branch Crowns of `Chandler' Strawberry in a Cold-climate Annual Production System

2004 ◽  
Vol 129 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Brent L. Black
Keyword(s):  
Production System ◽  
Foliar Spray ◽  
Plant Morphology ◽  
Cold Climate ◽  
Gibberellin Biosynthesis ◽  
Primary Concern ◽  
Nursery Plant ◽  
Crown Formation ◽  
Prohexadione Calcium ◽  
Branch Crown

Balancing vegetative growth with fruiting is a primary concern in strawberry (Fragaria ×ananassa Duch.) production. Where nursery plant selection and preconditioning are inadequate for runner control, additional approaches are needed. The gibberellin biosynthesis inhibitor prohexadione-Ca (commercial formulation Apogee) was tested over two seasons for suppressing fall runners of `Chandler' plug plants in a cold-climate annual hill production system. Prohexadione-Ca was applied as a foliar spray at active ingredient concentrations ranging from 60 to 480 mg·L-1, either as a single application 1 week after planting, or repeated at 3-week intervals. The lowest rate resulted in inadequate runner control, with some runners producing malformed daughter plants. Higher rates resulted in 57% to 93% reductions in fall runner numbers, with a concomitant increase in fall branch crown formation. There were no effects of the prohexadione-Ca treatments on plant morphology the following spring, and no adverse effects on fruit characteristics or yield. Chemical names used: prohexadione-calcium, calcium 3-oxido-4-propionyl-5-oxo-3-cyclohexene-carboxylate.

Leaf removal and prohexadione-calcium can modify Camarosa strawberry nursery plant morphology for plasticulture fruit production

2005 ◽  
Vol 85 (3) ◽  
pp. 665-670 ◽  
Author(s):  
J. Y. Reekie ◽  
P. R. Hicklenton ◽  
J. R. Duval ◽  
C. K. Duval ◽  
P. C. Struik
Keyword(s):  
Active Ingredient ◽  
Plant Morphology ◽  
Fruit Production ◽  
Gibberellin Biosynthesis ◽  
Fragaria Ananassa ◽  
Biosynthesis Inhibitor ◽  
Nursery Practices ◽  
Nursery Plant ◽  
Bare Root ◽  
Prohexadione Calcium

Mowing and the application of a new gibberellin biosynthesis inhibitor, prohexadione-calcium (ProCa), were studied as methods to modify the bare-root transplant morphology of Camarosa strawberry (Fragaria × ananassa Duchesne) in a Nova Scotia nursery. The effect these nursery practices had on fruit production in annual hill plasticulture was also determined. In one experiment Camarosa plants were sprayed with ProCa at an active ingredient concentration of 62.5 mg L-1 on Aug. 22, Sep. 05, or Sep. 19, 2001 and 2002, corresponding, respectively, to growing degree days (10°C base) of 800, 894 and 965 in 2001 and 726, 821 and 908 in 2002. Application on Aug. 22 increased production of daughter plants, especially those of marketable size, by increasing the number of daughters per meter of runner and allocating more dry matter to marketable daughters. In a second experiment, field plots were mowed and/or treated with ProCa at an active ingredient concent ration of 62.5 mg L-1 on Sep. 05 or Sep. 19, 2001 and 2002. All plants were dug in early October, shipped to Dover, Florida, and transplanted into plasticulture for fruit production. At digging, plants that had been mowed or treated with ProCa on Sep. 05 were reduced in plant height and total leaf area compared with untreated plants. Plants that were treated both with ProCa and mowed were the shortest. Fruit yield was higher from treated than from untreated plants. In 2001, the treatments increased early fruit production. Key words: Fragaria × ananassa, mowing, gibberellin biosynthesis inhibitor, phenology, height control

Prohexadione-calcium modifies growth and increases photosynthesis in strawberry nursery plants

2005 ◽  
Vol 85 (3) ◽  
pp. 671-677 ◽  
Author(s):  
J. Y. Reekie ◽  
P. R. Hicklenton ◽  
P. C. Struik
Keyword(s):  
Leaf Area ◽  
Growth Analysis ◽  
Foliar Spray ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Gibberellin Biosynthesis ◽  
Fragaria Ananassa ◽  
Growth Chambers ◽  
Prohexadione Calcium ◽  
Weight Allocation

Prohexadione-calcium (ProCa) at an active ingredient concentration of 62.5 mg L-1 was applied as a foliar spray to Camarosa and Sweet Charlie strawberry (Fragaria × ananassa Duchesne) plants in growth chambers to assess its effects on dry weight allocation and growth over 42 d. The height, leaf number, leaf area, and specific leaf area (SLA) of daughter plants and the total dry weights of their leaves, stems and roots were all affected by ProCa treatments. Treated plants weighed less than untreated plants for the first 28 d after treatment, but by 42 d, all plants were similar in total weight regardless of treatment. ProCa-treated plants consistently allocated more dry weight to roots, and proportionally less to shoots, and were reduced in height, leaf area and SLA. ProCa increased net photosynthesis in plants grown in growth chambers and in the field. Plants grown in the field responded to ProCa earlier, and their photosynthetic rates were higher (i.e., 23–34% higher in daught ers and 34–41% higher in mothers) than those grown in growth chambers. Key words: Fragaria × ananassa, gibberellin biosynthesis inhibitor, growth analysis, net photosynthesis

scholarly journals Natural variation in the control of flowering and shoot architecture in diploid Fragaria species

2021 ◽  
Author(s):  
Guangxun Fan ◽  
Javier Andres ◽  
Klaus Olbricht ◽  
Elli Koskela ◽  
Timo Hytonen
Keyword(s):  
Late Summer ◽  
Expression Level ◽  
Flower Initiation ◽  
Cool Temperature ◽  
Axillary Shoots ◽  
Shoot Architecture ◽  
Crown Formation ◽  
Branch Crown ◽  
Short Days ◽  
Fragaria Species

In perennial fruit and berry crops of the Rosaceae family, flower initiation occurs in late summer or autumn after downregulation of a strong repressor TERMINAL FLOWER1 (TFL1) and flowering and fruiting takes place the following growing season. Rosaceous fruit trees typically form two types of axillary shoots, short flower-bearing shoots called spurs and long shoots that are respectively analogous to branch crowns and stolons in strawberry. However, regulation of flowering and shoot architecture differs between species and environmental and endogenous controlling mechanisms have just started to emerge. In woodland strawberry (Fragaria vesca L.), long days maintain vegetative meristems and promote stolon formation by activating TFL1 and GIBBERELLIN 20-OXIDASE4 (GA20ox4), respectively, while silencing of these factors by short days and cool temperatures induces flowering and branch crown formation. We characterized flowering responses of 14 accessions of seven diploid Fragaria species native to diverse habitats in the northern hemisphere, and selected two species with contrasting environmental responses, F. bucharica Losinsk. and F. nilgerrensis Schlecht. ex J. Gay for detailed studies together with F. vesca. Similar to F. vesca, F. bucharica was induced to flower in short days at 18°C and regardless of photoperiod at 11°C after silencing of TFL1. F. nilgerrensis maintained higher TFL1 expression level and likely required cooler temperatures or longer exposure to inductive treatments to flower. We also found that high expression of GA20ox4 was associated with stolon formation in all three species, and its downregulation by short days and cool temperature caused branch crown formation in F. vesca and F. nilgerrensis, although the latter did not flower. F. bucharica, in contrast, rarely formed branch crowns, regardless of flowering or GA20ox4 expression level. Our findings highlighted diploid Fragaria species as a rich source of genetic variation controlling flowering and plant architecture, with potential applications in breeding of Rosaceous crops.

scholarly journals Influence of gibberellin inhibitors applied during flowering of nonirrigated 'Hass' avocado trees

2018 ◽  
Vol 53 (8) ◽  
pp. 918-923 ◽  
Author(s):  
Bruna do Amaral Brogio ◽  
Simone Rodrigues da Silva ◽  
Tatiana Cantuarias-Avilés ◽  
Sérgio Figueiredo Angolini ◽  
Edypol Guilherme Baptista ◽  
...  
Keyword(s):  
Shoot Growth ◽  
Block Design ◽  
Fruit Shape ◽  
Persea Americana ◽  
Fruit Yield ◽  
Gibberellin Biosynthesis ◽  
Alternate Bearing ◽  
Water Control ◽  
Hass Avocado ◽  
Prohexadione Calcium

Abstract: The objective of this work was to evaluate the effect of different gibberellin biosynthesis inhibitors on shoot growth above the panicle, as well as on fruit yield, size, and shape of nonirrigated 'Hass' avocado (Persea americana) trees. The experiment was carried out in a randomized complete block design, with five treatments, four replicates, and 40 trees. From 2013 to 2015, the following treatments were applied at full bloom, as foliar sprayings: water (control), 250 mg L-1 prohexadione-calcium, 2,500 mg L-1 trinexapac-ethyl, 1,750 mg L-1 paclobutrazol, and 350 mg L-1 uniconazole; the first two are acylcyclohexanediones and the last two, triazoles. Fruit yield, yield efficiency, and alternate bearing were not affected by the application of plant growth regulators. However, the gibberellin inhibitors increased fruit size and modified the fruit shape of nonirrigated 'Hass' avocado. Uniconazole reduces shoot growth above the panicle, and this effect may vary depending on environmental conditions, especially water supply.

Abnormalities in growth, development and physiological responses to biotic and abiotic stress in potato (Solanum tuberosum) transformed with Arabidopsis ETR1

2003 ◽  
Vol 141 (3-4) ◽  
pp. 333-347 ◽  
Author(s):  
M. M. HAINES ◽  
P. J. SHIEL ◽  
J. K. FELLMAN ◽  
P. H. BERGER
Keyword(s):  
Solanum Tuberosum ◽  
Receptor Gene ◽  
Plant Morphology ◽  
Transgenic Potato ◽  
Potato Industry ◽  
Primary Concern ◽  
Biotic And Abiotic Stress ◽  
Tuber Dormancy ◽  
Ethylene Action ◽  
Pleiotrophic Effects

Sprouted potato tubers lose nutritional value, and their increased content of reducing sugar renders them unsuitable for the french fry and chipping industries. Thus, tuber sprouting in storage is a primary concern of the potato industry, and is currently controlled by application of chemical sprout suppressants. Such suppressants are subject to widespread regulation by governmental agencies. The present study was initiated to investigate the role of the plant hormone ethylene in potato (Solanum tuberosum L.) tuber dormancy release. To this end, potato cv. ‘Russet Burbank’ was transformed with ETR1, an ethylene receptor gene from Arabidopsis. The resulting clones were genetically characterized to verify integration and expression of the ETR1 mRNA and protein. Transgenic clones showed developmental and morphologic changes in plant and tuber, and differing responses to environmental stress and pathogen attack relative to untransformed controls. Lengthening of dormancy was also observed in ETR1 antisense clones stored at 4 °C. Transgenic potato clones treated with solutions of silver thiosulfate (STS), an ethylene action inhibitor, showed restoration of normal plant morphology, while controls were unaffected. These results demonstrate the pleiotrophic effects of ethylene in potato, and identify a need for additional studies on the relationship between ethylene and tuber dormancy.

scholarly journals The Effects of Conditioning Strawberry Plug Plants under Altered Red/Far-red Light Environments

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1263-1267 ◽  
Author(s):  
Brent L. Black ◽  
Harry J. Swartz ◽  
Gerald F. Deitzer ◽  
Bryan Butler ◽  
Craig K. Chandler
Keyword(s):  
Production System ◽  
Day Treatment ◽  
Red Light ◽  
Field Performance ◽  
Cold Climate ◽  
Plant Performance ◽  
First Year ◽  
Greenhouse Production ◽  
Plastic Films ◽  
Short Day

The effect of altered red/far-red light environment on subsequent field performance of strawberry plug plants was tested. Two wavelength-selective plastic films were compared to neutral shade and full-sun control for conditioning `Chandler' strawberry plug plants before transplanting to a winter production system. The following year, plug plants of `Chandler', `Sweet Charlie', and `Allstar' were conditioned under the same treatments, with the addition of a continuous incandescent light and a short-day photoperiod, and plant performance was followed in the winter production system in Florida, a cold-climate annual hill system in Maryland, and in a low-input greenhouse production system. During the first year, the red light-filtering film slightly advanced fruiting in Florida. However, during the second year, the effect of the red light-filtering film was not significant, and a short-day treatment resulted in a greater reduction in runnering and increased early crown and flower development. For June-bearing strawberry plants maintained above 20 °C, altering the red/far-red environment did not consistently advance flowering.

scholarly journals The Use of Leaf Removal and Prohexadione-Ca to Modify `Camarosa' Strawberry Nursery Plant Morphology for Plasticulture Fruit Production

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 820B-820
Author(s):  
Julia Reekie* ◽  
Peter Hicklenton ◽  
John Duval ◽  
Craig Chandler ◽  
Paul Struik
Keyword(s):  
Plant Morphology ◽  
Plant Size ◽  
Fruit Production ◽  
Fruit Yield ◽  
Synthesis Inhibitor ◽  
Total Leaf Area ◽  
Growing Seasons ◽  
Nursery Plant ◽  
Nursery Field ◽  
Time Of Harvest

Our previous work on modifying strawberry plant morphology used either mowing to remove the leaf laminas and part of the petioles on `Camarosa', or a new reduced-risk gibberellin synthesis inhibitor, Prohexadione-Ca (ProCa), to restrict cell elongation in `Sweet Charlie'. These early studies showed promising results in acheiving desirable plant size and increasing fruit yield in annual hill plasticulture. Therefore, in the growing seasons of 2001 and 2002, we used `Camarosa' to explore the possibility of combining mowing and ProCa as a means of modifying strawberry transplant morphology in the nurseries, and studied its effect on fruit production in annual hill plasticulture. Plants were mowed and treated with 62.5 μL·L-1 of ProCa in a nursery field in Nova Scotia (45°26'N, 63°27'W). Treatments consisted of either mowing, the application of ProCa, or a combination of mowing and ProCa on one of two dates, 5 or 19 Sept. ProCa application early in the growing season had increased the production of daughter plants in the nursery. All plants were harvested in early October, and immediately transplanted in Dover, Fla. (28°00'N, 82°22'W). Fruits were collected twice weekly from late November to February or March. At time of harvest, both mowing and ProCa reduced plant height and total leaf area; plants which were treated with ProCa and mowed were the shortest. On average, treated plants had higher fruit yield as compared to untreated plants. In 2001, early fruit production in December was increased significantly in treated plants.

scholarly journals Vegetative Growth Responses of Citrus Nursery Trees to Various Growth Retardants

2010 ◽  
Vol 20 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Smit le Roux ◽  
Graham H. Barry
Keyword(s):  
Vegetative Growth ◽  
Foliar Application ◽  
Shoot Length ◽  
Internode Length ◽  
Citrus Limon ◽  
Gibberellin Biosynthesis ◽  
Growth Responses ◽  
Biosynthesis Inhibitors ◽  
Nursery Trees ◽  
Prohexadione Calcium

As part of a larger study to improve rind color of citrus (Citrus spp.) fruit, this initial study was conducted to determine the concentration of various gibberellin-biosynthesis inhibitors required to elicit a biological response in citrus trees, as measured by vegetative growth. Paclobutrazol and GA3 were included as control treatments at concentrations known to elicit growth-retarding or growth-promoting effects, respectively. Repeated (×4) foliar applications of GA3 (at 64 ppm) increased growth of ‘Eureka’ lemon (Citrus limon) shoots by 63%, with no significant effect on rootstock and scion diameters. Repeated foliar applications of prohexadione-calcium (ProCa) at various concentrations (100, 200, 400, or 800 ppm) as well as uniconazole (at 500 or 1000 ppm) and paclobutrazol (at 0.25%) had no effect on rootstock or scion diameters 8 months after the first application. The high concentrations of ProCa (800 ppm) and uniconazole (1000 ppm), and the paclobutrazol treatment (0.25%) reduced shoot length compared with the control. Uniconazole at 1000 ppm resulted in the most growth retardation, which resulted in 34% shorter shoot length than the control. Although the number of nodes on the longest shoot did not differ from the untreated control, internode length differed significantly among treatments. ProCa at 400 and 800 ppm, uniconazole at 1000 ppm, and paclobutrazol at 0.25% significantly reduced internode length relative to the control by 31%, 56%, 50%, and 28%, respectively. Vegetative growth of ‘Eureka’ lemon nursery trees was retarded following the repeated (×4) foliar application of gibberellin-biosynthesis inhibitors. ProCa at 400 to 800 ppm and uniconazole at 1000 ppm were identified as prospective treatments for further field studies to test their effects on rind color enhancement of citrus fruit.

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