scholarly journals Flower Bud Stage and Chill Hours Influence the Activity of GA3 Applied to Rabbiteye Blueberry

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 316-318 ◽  
Author(s):  
D.S. NeSmith ◽  
Gerard Krewer

Individual flower clusters of `Tifblue' rabbiteye blueberry (Vaccinium ashei Reade) were treated with 300 ppm GA at several flower bud stages to determine the activity of the growth regulator in promoting fruit set. Applications were made one time only at a specified stage of flower development, or once followed by a second application. A single application of GA when flower buds had elongated but corollas had not expanded (stage 5) led to the largest increase in fruit set. Two applications of GA, 10 to 18 days apart, increased fruit set compared with a single application at flower developmental stages other than stage 5. Fruit set promoted by a single spray of GA imposed on fully expanded corollas (stage 6) decreased with increasing number of chill hours (350, 520, 760, or 1150). Chemical names used: gibberellic acid (GA).

HortScience ◽  
2002 ◽  
Vol 37 (4) ◽  
pp. 666-668 ◽  
Author(s):  
D. Scott NeSmith

Experiments were conducted during 1999 and 2000 at Griffin, Ga., with rabbiteye blueberries (Vaccinium ashei Reade) to determine how the growth regulator CPPU affected fruit set, berry size, and yield. CPPU (applied at two different timings) was used alone, and in conjunction with GA3 on mature, field-grown `Tifblue' plants. A control treatment without either growth regulator was also included. The CPPU concentration used was 10 mg·L-1 (a single application per treatment), and the GA3 concentration used was 200 mg·L-1 (two applications per treatment). Results from both years showed a positive benefit of CPPU with respect to fruit set and berry size, especially in the absence of GA3. Depending on timing, berry number per plant was increased by more than 200% in 1999 using CPPU. Berry size increases of more than 30% occurred in 2000 when CPPU alone was applied at 17 d after flowering (DAF). CPPU did not increase berry size of GA3-treated plants in either year. Total yield per plant during 2000 was 5.0, 7.1, and 8.3 kg for control, CPPU applied 7 DAF, and CPPU applied 17 DAF treatments, respectively, without GA3. While CPPU did substantially increase fruit set, berry size, and yield of `Tifblue', there was a notable delay in fruit ripening. These results suggest that CPPU may be useful for increasing yield of rabbiteye blueberries under conditions of inadequate fruit set (such as occurs in much of the Southeast), but a delay in ripening will likely result. Chemical names used: N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU); gibberellic acid (GA3).


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 575d-575
Author(s):  
D. Scott NeSmith ◽  
Gerard Krewer ◽  
Orville Lindstrom

Recent research in Georgia indicated gibberellic acid (GA3) could possibly be used to induce fruit set of freeze damaged rabbiteye blueberry (Vaccinium ashei) blooms. This research was conducted to determine the subfreezing temperature limit at which GA3 could be expected to be of use in salvaging a crop with freeze-damaged flowers. Rabbiteye blueberries with flower buds at stages 5 to 6 of development (fully elongated corollas and open blooms) were exposed to temperatures of 0, –1, –3, and –4.5°C in growth chambers to simulate overnight freezing events. After cold exposure, plants were placed in a greenhouse with a hive of bumblebees. Half of the plants were treated with GA3 and half were not. The number of flowers and subsequent fruit were recorded in order to calculate fruit set. Temperatures of –1°C and below caused fruit set resulting from pollination by bees to decline compared to control plants; whereas, flowers treated with GA3 had fruit set comparable to control plants down to –3°C. Plants exposed to –3°C had 50% to 80% fruit set when treated with GA3 compared to 5% to 19% fruit set for untreated plants. Temperatures of –4.5°C caused severe flower damage, and fruit set by pollination or GA3 was very poor (<2%). These results indicate that GA3 should be useful in salvaging a blueberry crop exposed to temperatures of – 1 to –3.5°C during bloom.


2018 ◽  
Vol 40 (2) ◽  
Author(s):  
Lorena Moreira Carvalho Lemos ◽  
Luiz Carlos Chamhum Salomão ◽  
Dalmo Lopes de Siqueira ◽  
Olinto Liparini Pereira ◽  
Paulo Roberto Cecon

Abstract There are little information in the scientific literature on flowering and fruiting of ‘Ubá’ mango trees. These information enables to know the proportion of hermaphrodite flowers in inflorescence, fruit set percentage and developmental stages of the fruit. In this study evaluations on inflorescence and fruit development of the ‘Ubá’ mango tree (Mangifera indica L.) were carried out, as well as the determination of the required number of heat units for full fruit development. Thirty branches whose terminal buds were swollen were selected from five mango trees. With the aid of a camera and a caliper, the panicle and fruit development were evaluated weekly until full fruit development. A digital thermometer was used to record ambient temperatures during fruit development in order to estimate the number of heat units required for complete development of the fruits. Male and hermaphrodite flowers of the panicles were also identified and counted. The developmental cycle of ‘Ubá’ mango from the beginning of apical bud swelling to commercial harvest of the fruit lasted 168 days in 2011 and 154 days in 2012. The number of hermaphrodite flowers and the percentage of fruit set in the inflorescence in 2011 were 32.3 and 0.066%, respectively; and 122.1 and 0.099% in 2012, respectively. There was accumulation of 3,173 heat units from flower bud swelling to full development of the ‘Ubá’ mangoes.


1969 ◽  
Vol 89 (3-4) ◽  
pp. 159-168
Author(s):  
Carlos A. Flores ◽  
Winston De la Torre ◽  
Miguel Monroig ◽  
Wigmar González

Applications of gibberellic acid (GA), paclobutrazol and gibberellic acid (Paclo/GA), fluoridone and gibberellic acid (FL/GA), and abscisic acid (ABA) were made to synchronize flowering in coffee trees (Coffea arabica L.). Overall growth of trees and branches was not affected by the treatments. Production of new leaves was not affected by the treatments. However, the Paclo/GA treatment tended to increase the production of secondary branches. Flower bud production was affected by the ABA treatment during the first three weeks, showing an initial reduction in number and a late development of buds. Plants receiving the GA treatment produced more flowers during the first week of evaluation as well as a higher number and greater weight of mature fruits during the first week of harvesting. 


HortScience ◽  
2016 ◽  
Vol 51 (6) ◽  
pp. 697-702 ◽  
Author(s):  
Chen Xingwei ◽  
Thohirah Lee Abdullah ◽  
Sima Taheri ◽  
Nur Ashikin Psyquay Abdullah ◽  
Siti Aishah Hassan

Synsepalum dulcificum from the family Sapotaceae is known as miracle fruit and is a valuable horticultural species. All plant parts are of medicinal importance whereas the fruit known as magic berry, miracle berry, or sweet berry is consumed fresh. Surprisingly, very little is known on the species in terms of flower morphology and flower development. In this study, an observation on the flower morphology and flower development of miracle fruit has been made with the aid of microscopic techniques. Miracle fruit flower requires 100 days to develop from reproductive meristem to full anthesis. The flower development can be divided into six stages based on the size and appearance of the flower bud. The fruit with persistent style developed and ripened 90 days after anthesis. Heavy fruit drop was observed at 40–60 days after anthesis which contributed to the final fruit set of average of 5.06% per plant. Through this study, miracle fruit is strongly insect pollinated and prevents self-fertilization. A study on pollination ecology is needed to identify the pollinator for miracle fruit, as this is important in manipulating fruit loading in the future.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 537C-537
Author(s):  
J.G. Williamson ◽  
R.L. Darnell

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.


HortScience ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 146-148 ◽  
Author(s):  
Ross E. Byers ◽  
R.P. Marini

Peach trees [Prunus persica (L.) BatSch.] blossom-thinned by hand were overthinned due to poor fruit set of the remaining flowers; however, their yield was equivalent to trees hand-thinned 38 or 68 days after full bloom (AFB). Blossom-thinned trees had three times the number of flower buds per unit length of shoot and had more than two times the percentage of live buds after a March freeze that had occurred at early bud swell the following spring. Blossom-thinned trees were more vigorous; their pruning weight increased 45%. For blossom-thinned trees, the number of flowers per square centimeter limb cross-sectional area (CSA) was two times that of hand-thinned trees and four times that of the control trees for the next season. Fruit set of blossom-thinned trees was increased four times. Flower buds on the bottom half of shoots on blossom-thinned trees were more cold tolerant than when hand-thinned 68 days AFB. Fruit set per square centimeter limb CSA was 400% greater the following year on blossom-thinned trees compared to controls. Removing strong upright shoots on scaffold limbs and at renewal points early in their development decreased dormant pruning time and weight and increased red pigmentation of fruit at the second picking. The number of flower buds per unit shoot length and percent live buds after the spring freeze were negatively related to crop density the previous season for trees that had been hand-thinned to varying crop densities at 48 days AFB. According to these results, blossom thinning and fruit thinning to moderate crop densities can influence the cold tolerance of peach flower buds in late winter.


HortScience ◽  
1995 ◽  
Vol 30 (6) ◽  
pp. 1241-1243 ◽  
Author(s):  
D. Scott NeSmith ◽  
Gerard Krewer ◽  
Mark Rieger ◽  
Ben Mullinix

In a series of experiments, gibberellic acid (GA3) was applied to rabbiteye blueberries (Vaccinium ashei Reade) under field and greenhouse conditions to determine if fruit set could be improved following physical or freeze injury to flowers. In field experiments, physically damaged flowers (i.e., corollas and styles removed, styles only removed, or ovaries lanced) of `Climax' and `Tifblue' treated with GA3 (4% ProGib at 250 mg·liter–1) set substantially more fruit than nontreated, damaged flowers. Under green-house conditions, GA3 applied postfreeze to `Tifblue' and `Brightwell' resulted in increased fruit set compared to unsprayed control plants of the same cultivars. Freeze-damaged plants had substantially reduced fruit set overall but to a much lesser extent for GA3-treated plants than for those not treated with GA3. Individual fruit weight was reduced by GA3 applications, as was berry seediness. Results from these greenhouse and field trials suggest that GA3 can be used to salvage a blueberry crop following a moderate freeze during bloom.


2019 ◽  
Vol 5 (1) ◽  
pp. 1-10
Author(s):  
. HAMIM ◽  
ZAHRUL ROMADLON ◽  
. DORLY

Nyamplung (Calophyllum inophyllum), a non-edible producing plant, is a tropical plant traditionally used by local residents as firewood, building material and medicinal plants. The research aimed to study the development of flower and fruit as well as oil content of nyamplung seeds. Two adult trees (P1 and P2) with different provenance were used in experiment. Morphology of flower and fruit, and seed germination were observed from the field, while the microscopic anatomical observations and oil content analysis were carried out in the laboratory. The result showed that a single generative bud generally had 8-15 flowers. The flower was arranged in bunches, with 4 petals, 4 sepals, single pistil and 4 files of anthers surrounded the pistil. In some cases, the flowers had 5 sepals, or 3 sepals and 3 anthers files. Fruits were round, green and turned to harden with brownish color during maturation. Flower bud grown from bud was ready to blossom 27 days after initiation (DAI). There were up to 48.52% flower buds drop at 24 DAI, and they were still increase up to 64.5% flower drop during the whole of flower development. The observation also showed that fruit drop rate of P2 plant was higher than P1. After flower bloom for 3 or 4 days after anthesis, the flowers started to lose their parts. The fruits started to ripe 8-10 week after anthesis (WAA). Seeds from P2 tree had oil content of 51.79%, which was higher than the P1 tree (42.57%). 


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Yanting Chang ◽  
Tao Hu ◽  
Wenbo Zhang ◽  
Lin Zhou ◽  
Yan Wang ◽  
...  

Abstract Tree peony (Paeonia suffruticosa Andrew) is a popular ornamental plant due to its large, fragrant and colorful flowers. The floral development is the most important event in its lifecycle. To explore the mechanism that regulate flower development, we sequenced the flower bud transcriptomes of ‘High Noon’, a reblooming cultivar of P. suffruticosa × P. lutea, using both full-length isoform-sequencing (ISO-seq) and RNA-seq were sequenced. A total of 15.94 Gb raw data were generated in full-length transcriptome sequencing of the 3 floral developmental stages, resulting 0.11 M protein-coding transcripts. Over 457.0 million reads were obtained by RNA-seq in the 3 floral buds. Here, we openly released the full-length transcriptome database of ‘High Noon’ and RNA-seq database of floral development. These databases can provide a fundamental genetic information of tree peony to investigate its transcript structure, variants and evolution. Data will facilitate to deep analyses of the transcriptome for flower development.


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