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פותח על ידי קלירמאש פתרונות בע"מ -
Carbohydrate supply and demand during fruit development in relation to productivity of grapefruit and 'murcott' mandarin
Year:
1996
Source of publication :
Acta Horticulturae
Authors :
ארנר, יאיר
;
.
Volume :
416
Co-Authors:
Bustan, A., Kennedy-Leigh Centre for Horticultural Research, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel
Goldschmidt, E.E., Kennedy-Leigh Centre for Horticultural Research, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel
Erner, Y., Department of Horticulture Agricultural Research Organization, Bet Dagan 50250, Israel
Facilitators :
From page:
81
To page:
88
(
Total pages:
8
)
Abstract:
A comparison was conducted between grapefruit (Citrus paradisi Macf. cv. Marsh seedless), [large fruit, high, regular yields] and mandarin (Citrus reticulata cv. Murcott) [small fruit, alternate bearing]. To determine fruit demand, maximal fruit absolute growth rate (AGR) and fruit relative growth rate (RGR), trees were trunk girdled and extremely thinned (grapefruit); alternatively, 'Off and regular (control) trees were used (Murcott). Fruit growth was followed weekly and transformed into carbohydrate consumption by CHNOS analysis (McDermitt and Loomis, 1981), and respiration measurements. In grapefruit, fruit thinning resulted in higher AGR and RGR throughout most of fruit development, suggesting long periods of source limitation. Calculation of the daily available carbohydrate also indicated that in grapefruit, fruit demand for carbohydrate exceeded the supply. In 'Murcott', 'Off fruit revealed relatively low AGR values, though higher than 'On' fruit throughout the season. During stage I of fruit development RGR values were unstable and not unequivocally indicative for sink-or source limitations. However, fruit absolute demand was significantly lower than the calculated supply during stage I and the beginning of stage II. Source limitation occurred only when fruit size reached about 20 g (FW), 120 days after anthesis. It is suggested that fruitlet size is a major factor in the source-sink interplay of developing fruits. Murcott fruit development is sink limited for the first three months due to its remarkably small initial size (about 6 mgFW). When source limitation takes over, the self-thinning mechanisms are not fully active any more. Fruit number per tree remains higher than desired, resulting in small fruit size at harvest and overcropping symptoms. In grapefruit, on the other hand, initial fruitlet size is large (72 mgFW) and fruit number per tree is adjusted by the self-thinning mechanism to the available supply during stage I, thus preventing crop overload and resource depletion.
Note:
Related Files :
Citrus
Citrus reticulata
Citrus x paradisi
Crop modelling
fruit size
Relative growth rate
Source-sink relations
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר מתוך כינוס
;
.
Language:
אנגלית
Editors' remarks:
ID:
28549
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:40
Scientific Publication
Carbohydrate supply and demand during fruit development in relation to productivity of grapefruit and 'murcott' mandarin
416
Bustan, A., Kennedy-Leigh Centre for Horticultural Research, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel
Goldschmidt, E.E., Kennedy-Leigh Centre for Horticultural Research, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel
Erner, Y., Department of Horticulture Agricultural Research Organization, Bet Dagan 50250, Israel
Carbohydrate supply and demand during fruit development in relation to productivity of grapefruit and 'murcott' mandarin
A comparison was conducted between grapefruit (Citrus paradisi Macf. cv. Marsh seedless), [large fruit, high, regular yields] and mandarin (Citrus reticulata cv. Murcott) [small fruit, alternate bearing]. To determine fruit demand, maximal fruit absolute growth rate (AGR) and fruit relative growth rate (RGR), trees were trunk girdled and extremely thinned (grapefruit); alternatively, 'Off and regular (control) trees were used (Murcott). Fruit growth was followed weekly and transformed into carbohydrate consumption by CHNOS analysis (McDermitt and Loomis, 1981), and respiration measurements. In grapefruit, fruit thinning resulted in higher AGR and RGR throughout most of fruit development, suggesting long periods of source limitation. Calculation of the daily available carbohydrate also indicated that in grapefruit, fruit demand for carbohydrate exceeded the supply. In 'Murcott', 'Off fruit revealed relatively low AGR values, though higher than 'On' fruit throughout the season. During stage I of fruit development RGR values were unstable and not unequivocally indicative for sink-or source limitations. However, fruit absolute demand was significantly lower than the calculated supply during stage I and the beginning of stage II. Source limitation occurred only when fruit size reached about 20 g (FW), 120 days after anthesis. It is suggested that fruitlet size is a major factor in the source-sink interplay of developing fruits. Murcott fruit development is sink limited for the first three months due to its remarkably small initial size (about 6 mgFW). When source limitation takes over, the self-thinning mechanisms are not fully active any more. Fruit number per tree remains higher than desired, resulting in small fruit size at harvest and overcropping symptoms. In grapefruit, on the other hand, initial fruitlet size is large (72 mgFW) and fruit number per tree is adjusted by the self-thinning mechanism to the available supply during stage I, thus preventing crop overload and resource depletion.
Scientific Publication
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