scholarly journals Patterns of Sorbitol Metabolism and Availability during Apple Fruit Set

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 887B-887
Author(s):  
Douglas D. Archbold* ◽  
Marta Nosarszewski
Keyword(s):  
Specific Antibody ◽  
Fruit Set ◽  
Sucrose Concentration ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Sorbitol Dehydrogenase ◽  
Prior Work ◽  
Fruit Drop ◽  
June Drop ◽  
Sorbitol Metabolism

Acquiring sufficient carbohydrate is essential for successful apple fruit set. Sorbitol may be the dominant carbohydrate imported by growing fruit, and the rate of sorbitol accumulation may be a function of NAD-dependent sorbitol dehydrogenase (SDH; EC 1.1.1.14) activity. Prior work indicated that SDH activity from whole fruit (seeds plus cortex) increased for 2 or 3 weeks after initiation of fruit growth and then declined through 5 weeks. Using SDH activity assays, an SDH-specific antibody, and SDH-specific probes in Northern analyses, it is evident that SDH is expressed and is active in both apple seed and cortex tissue during the first few weeks of fruit growth. On a per unit protein basis, SDH activity in seeds increased by the pattern described above while that in fruit was generally lower and constant. During this same period of time, the sorbitol content of the expressed sap of apple shoots was analyzed. The sorbitol concentration was 50- to 100-fold higher than the sucrose concentration. The concentrations of both carbohydrates changed in parallel to the change in SDH activity of whole fruit and seeds. The lowest SDH activity and sap sorbitol levels preceded and/or coincided with the beginning of the natural fruit drop (or June drop) period.

scholarly journals Sorbitol Dehydrogenase Activity of Apple Fruit is Affected by Defoliation and Girdling

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 683d-683
Author(s):  
Douglas D. Archbold
Keyword(s):  
Carbohydrate Metabolism ◽  
Dehydrogenase Activity ◽  
Primary Source ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Sorbitol Dehydrogenase ◽  
Vascular Connection ◽  
Low Levels ◽  
June Drop

Following June drop, apple fruit growth depends on sorbitol import as the primary source of carbon. Sorbitol dehydrogenase plays a key role in carbohydrate metabolism by conversion of sorbitol to fructose, which then enters the general carbohydrate pool. Blocking the pathway and eliminating the source of sorbitol to the fruit by girdling the stem and defoliation after June drop resulted in a decline and eventual cessation of fruit growth. The fruit did not abscise however. Fruit sorbitol and starch levels declined while the fructose, glucose, and sucrose pools did not change. SDH activity declined to low levels and was not detectable in many fruit. The decline in SDH activity was evident 1 week after applying the treatments. A few fruit that resumed growth, presumably after the vascular connection was re-established across the girdle, exhibited normal SDH activity. Feeding sorbitol to whole fruit in vitro via the cut stem raised SDH activity in some fruit, although it was still below control levels.

Sorbitol dehydrogenase expression and activity during apple fruit set and early development

2004 ◽  
Vol 121 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Marta Nosarszewski ◽  
Ann M. Clements ◽  
A. Bruce Downie ◽  
Douglas D. Archbold
Keyword(s):  
Early Development ◽  
Fruit Set ◽  
Apple Fruit ◽  
Sorbitol Dehydrogenase ◽  
Expression And Activity

scholarly journals Development and Testing of a Model to Rapidly Predict Apple Thinner Response

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 793C-793 ◽  
Author(s):  
D.W. Greene* ◽  
A.N. Lakso ◽  
T.L. Robinson
Keyword(s):  
New York ◽  
Growth Rate ◽  
Fruit Set ◽  
Accurate Method ◽  
Fruit Growth ◽  
Cold Weather ◽  
Accurate Predictor ◽  
Accuracy Of Prediction ◽  
June Drop ◽  
Fruit Diameter

Several thinning experiments were initiated in 2003 to test the hypothesis that monitoring fruit growth is an appropriate and accurate method to predict final fruit set early enough to apply supplemental thinners if appropriate. A total of eight thinning treatments were applied in Massachusetts and New York. On the day of thinner application 70 to 100 spurs were tagged on 4-8 trees (replications). All fruit within a spur were individually identified and fruit were measured. At 2 to 3 day intervals fruit diameter was measured at a designated point on the fruit. Growth rate of the fastest growing 20 fruit on the untreated trees was used as the criteria to determine growth rate of fruit that would persist to harvest. A fruit on a treated tree was predicted to abscise if growth rate slowed to 50% or less of the growth rate of the 20 fastest growing fruit on untreated trees. Cold weather in 2003 following thinner application slowed the response time to thinners. Thinning treatments were applied to Delicious, Golden Delicious, McIntosh, and Gala at 7-9-mm stage. BA, carbaryl, and combinations of NAA and carbaryl were used. In Massachusetts accuracy of prediction of final fruit set at 7-11 days after application ranged from 87% to 100% with and average of 95% accuracy compared to final observed drop at the end of June drop in July. In Geneva, N.Y., the temperature was so unseasonably cold following application that prediction of final set at 7 to 11 days after application was between 68% and 79% with an average of 74% accuracy. We conclude that prediction of final fruit set following growth rate of individual fruit shows promise as an accurate predictor of final fruit set early enough to apply supplemental thinners if appropriate.

scholarly journals Influence of M9 Rootstock on the Reproductive Behaviour of Apple Cultivars under Dry, Semi-arid Growing Conditions

2013 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
Hafuz Domi ◽  
Telat Spahiu ◽  
Endrit Kullaj ◽  
Fadil Thomaj
Keyword(s):  
Fruit Set ◽  
Sugar Content ◽  
Global Radiation ◽  
Reproductive Behaviour ◽  
Fruit Growth ◽  
Western Coast ◽  
Growth Dynamic ◽  
Golden Delicious ◽  
Apple Cultivars ◽  
June Drop

In the last decade, apple has been intensively cultivated in the western coast of Albania. The scope of this research was to study the influence of M9 rootstock on the reproductive behaviour of apple cultivars ‘M. Gala’, ‘Golden Delicious’, ‘Starking’, ‘Fuji’ and ‘Pink Lady’. The trial was conducted from 2010 – 2011 in 5-year old orchards with 2,250 trees/ha grown as French axe and in full production located in Lushnja. The following indicators were measured: diameter of two main branches, number of fruits/branch, fruit growth dynamic and sugar content (%). Global radiation, temperature and humidity were recorded. The reproduction behaviour has also been measured by fruiting spurs in the general structure of the canopy as well as the number of fruits formed for each cultivar. The results have shown that in terms of fruit set, cultivars are ranked as follows: ‘M. Gala’ with the highest number of fruits, then ‘Golden Delicious’, ‘Fuji’, ‘Pink Lady’ and ‘Starking’, respectively. The dynamic of fruit dropping shows that ‘Starking’, having the lowest fruit set, after the June drop is more stable while ‘M. Gala’, with the highest fruit set, besides an abundant June drop, had another drop in July.  This is due to higher competition among the fruits and failure of the rootstock to supply the adequate quantities of sap. In terms of fruit growth dynamic, it was observed that intensive growth was measured for all the cultivars during the end of July after which fruit growth slowed down. Changes between cultivars were observed in relation to the maturation period of each cultivar, with ‘M. Gala’ maturing in August, ‘Fuji’ and ‘Pink Lady’ in October and November. ‘Starking and ‘Golden Delicious’ cultivars had a more rapid maturation (20 September), accompanied with a higher sugar content which is far more related to climatic factor rather than M9 rootstock. In conclusion, it was found that the cultivars under study have different reproductive behaviour with M9 rootstock. It can also be stated that ‘Starking’ is not appropriate for this coastal region due to inadequate fruiting behaviour.

scholarly journals 684 Thinning and Crop Load Effects on Apple Fruit Growth

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 516E-517
Author(s):  
Duane W. Greene
Keyword(s):  
Growth Rate ◽  
Pollen Germination ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Initial Assessment ◽  
Crop Load ◽  
Specific Chemical ◽  
Load Effects ◽  
Viable Seeds ◽  
June Drop

Chemical thinners can be classified as either blossom thinners or postbloom thinners. Blossom thinners act by inhibit further pollination, pollen germination, or pollen tube growth. At petal fall it is not possible to distinguish between fruit that have been injured by blossom thinners, and those that will persist and continue to grow. The receptacles of blossom thinned fruit do not grow, whereas fruit that has not been treated and that also contain viable seeds, resumes growth within 4 to 6 days, depending upon temperature. Abscission of fruit treated with postbloom thinners does not usually occur until 1.5 to 3 weeks after application. Frequently, it is possible to identify fruit that will abscise and to make an initial assessment of thinning efficacy, within 4 to 6 days following application by measuring fruit growth rate. A reduction in fruit growth by as little as 15% to 20% less than rapidly growing fruit is usually sufficient to assume that the fruit will abscise sometime during the June drop period. The effects of specific chemical thinners on fruit growth and subsequent thinning will be discussed.

scholarly journals Influence of Preharvest AVG Application on the Activity of Sorbitol Dehydrogenase in Apple Fruit

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1143C-1143
Author(s):  
Valeria Sigal-Escalada ◽  
Douglas D. Archbold
Keyword(s):  
Ethylene Production ◽  
Apple Fruit ◽  
Sorbitol Dehydrogenase ◽  
Ripening Process ◽  
Fruit Drop ◽  
Harvest Dates ◽  
Key Enzyme ◽  
Apple Cultivars ◽  
Fuji Apple ◽  
Over Time

Sorbitol dehydrogenase (SDH) is a key enzyme in apple fruit converting sorbitol into fructose. SDH activity in `Fuji' apple was reported to increase close to harvest, perhaps as part of the ripening process. Aminoethoxyvinylglycine (AVG) is used to delay fruit ripening and prevent fruit drop, though its effect on sorbitol metabolism is not known. To determine if the late season increase in SDH activity is common among apple cultivars and if AVG use affects SDH expression and activity, AVG was applied to `Lodi', `Redchief Delicious', and `Red Fuji' trees 4 weeks before harvest. Control and AVG-treated fruit were collected 1 week prior to, at, and 1 week after the normal harvest date for assessment of ethylene production over time after harvest and SDH presence and activity at harvest. Ethylene production in control fruit increased after harvest and AVG reduced it in all cultivars. `Redchief Delicious' fruit had the highest ethylene production of the treated samples. The levels of SDH activity in controls were similar across dates for `Redchief Delicious' and showed no consistent pattern in the other cultivars. `Redchief Delicious' and `Red Fuji' showed the highest and lowest levels of SDH activity, respectively. AVG did not affect SDH activity in `Redchief Delicious', and substantially increased SDH activity in `Red Fuji' on each of the three harvest dates, and, in `Lodi', only 1 week after normal harvest. SDH presence was confirmed through immunoblotting for all cultivars and harvest dates. Overall, fruit with the greatest reduction in ethylene production in response to AVG also showed changes in SDH activity.

scholarly journals Endogenous hormone causes flower and fruit drop of wax apple (Syzygium samarangense cv. Citra)

2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Etik Wukir Tini ◽  
T.A. Dwi Haryanto ◽  
Sakhidin Sakhidin ◽  
Saparso Saparso
Keyword(s):  
Fruit Development ◽  
Fruit Set ◽  
Apple Fruit ◽  
Total Sugar ◽  
Endogenous Hormones ◽  
Fruit Maturation ◽  
Fruit Drop ◽  
Flower And Fruit Development ◽  
Indole 3 Acetic Acid ◽  
Days After Anthesis

The aim of this study was to obtain information about the content of endogenous hormones that causes flowers and fruit drop of wax apple. The variables observed in the six stages of flower and fruit development that drop easily and retention of indole-­3-­acetic acid (IAA), cytokinin (zeatin and kinetin), gibberellins (GA3), 1­-amino cyclopropane­-1-­carboxylic acid (ACC), total sugar, and starch. Six stages of development of wax apple fruit: (1) Bud Development (initial flowering) 0­-3 days before anthesis. (2) Anthesis (perfect blooming flowers), 0­-7 days after anthesis. (3) Fruit set, 7­-14 days after anthesis. (4) Fruit development, 14-­28 days after anthesis. (5) Fruit Maturation, 28­-35 days after anthesis. (6) Fruit ripening, 35­-50 days after anthesis. The results showed that the content of IAA, zeatin, GA3, and total sugar of flowers and fruit of wax apple at 6 stages that would fall smaller than those of retention and ACC content and starch was higher in flower and fruits that drop easily than retention. The kinetin content in the flower development that drop easily is smaller than the retention but in the fruit development the kinetin content is not significantly different between those that drop easily and retention.

scholarly journals Development of a Fruitlet Growth Model to Predict Thinner Response on Apples

HortScience ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 584-587 ◽  
Author(s):  
Duane W. Greene ◽  
Alan N. Lakso ◽  
Terence L. Robinson ◽  
Phillip Schwallier
Keyword(s):  
Growth Rate ◽  
Fruit Set ◽  
Growth Period ◽  
Fruit Growth ◽  
Series Of Experiments ◽  
Individual Trees ◽  
Viable Method ◽  
Final Effect ◽  
June Drop ◽  
Measurement Period

Previous reports have provided evidence that measuring fruit growth rate may be a viable method to predict if a fruit will abscise or persist through the June drop period. A series of experiments were carried out over several years to develop a procedure that could be used to predict the response to a chemical thinner application within 7 to 8 days after application and before thinners exhibit their final effect. The procedure developed involves tagging 105 spurs on seven individual trees distributed appropriately in the orchard. A minimum of two measurements must be made, one 3 to 4 days after application and again 7 to 8 days after application. This model requires that fruit measurement should not start before fruit grow to a diameter of 6 mm and individual fruit within a spur should be numbered and identified. The model is based on the assumption that if fruit growth rate of a particular fruit over the measurement period is less than 50% of the growth rate of the fastest growing fruit on the tree during the same growth period, it will abscise, whereas if fruit growth rate exceeds 50% of the growth rate of the fastest growing fruit, it will persist. All data can be entered into an Excel spreadsheet and the output in the summary page gives the predicted fruit set expressed as percentage of the total number of fruit present. The strategy for crop load adjustment with chemical thinners has evolved over the years to a point where most orchardists plan and are prepared to make two or more thinner applications. The dilemma associated with this approach is to determine if additional thinner applications are necessary. Up to this point a tool designed specifically to provide this information has not been developed.

scholarly journals Premature Apple Fruit Drop: Associated Fungal Species and Attempted Management Solutions

Horticulturae ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 31 ◽  
Author(s):  
Khamis Youssef ◽  
Sergio Ruffo Roberto
Keyword(s):  
Fungal Pathogens ◽  
Fruit Set ◽  
Phytopathogenic Fungi ◽  
Apple Fruit ◽  
In Vitro Tests ◽  
Variable Effect ◽  
Thiophanate Methyl ◽  
Fruit Drop ◽  
Naturally Occurring

The aim of this research was to determine the incidence and possible causal pathogen(s) of premature apple fruit drop (PAFD), and also to assess some fungicides for controlling the disease organisms, in order to promote a sustainable system in orchards. The prevalence and natural incidence of apple fruit drop in cv. Anna was assessed during the 2017–2018 growing seasons in Nubaria and Cairo–Alexandria regions, Egypt. Phytopathogenic fungi were isolated from dropped fruit, and four fungicides, pyraclostrobin + boscalid, difenoconazole, carbendazim, and thiophanate methyl, were tested against the diseases in vitro and under naturally occurring infections in the field. Several phytopathogenic fungi, including Alternaria alternata, Cladosporium cladosporioides, Fusarium semitectum, and Penicillium spp., were associated with apple fruit drop. A. alternata was the most frequently isolated fungus occurring during the investigation. Pathogenicity tests confirmed that the maximum percentage of apple fruit drop was noted when petioles and fruits were inoculated with mixed fungal pathogens using branch sections with fruit. In vitro tests showed that the fungicides had a variable effect against the fungal isolates depending on the concentration used. All fungicides completely inhibited the growth of A. alternata, C. cladosporioides, and F. semitectum at 400 mg·L−1. Under naturally occurring infections, thiophanate methyl applied at fruit set had the greatest effect (81.68%) against PAFD, followed by difenoconazole (73.76%), pyraclostrobin + boscalid (70.29%), and carbendazim (66.34%). The results indicated that PAFD may in part be a result of diseases caused by certain phytopathogenic fungi, which could be controlled using a number of fungicides applied at the beginning of fruit set.

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