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Effects of defruiting on source‐sink relationship, carbon budget, leaf carbohydrate content and water use efficiency of apple trees
Author(s) -
Wibbe Michael L.,
Blanke Michael M.
Publication year - 1995
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1995.tb00964.x
Subject(s) - canopy , malus , photosynthesis , horticulture , perennial plant , water use efficiency , botany , biology , tree canopy , respiration
Three‐year‐old apple ( Malus domestica Borkh. cv. Golden Delicious) trees with ca 5 m 2 leaf area each were grown in situ in lysimeters and defruited either in August. September or October. Net photosynthesis, dark respiration and water use efficiency were measured for 5 days prior to and after fruit removal. using tree canopy chambers and infrared gas analysis with a dedicated interface and software. Net photosynthesis of the tree canopy declined after defruiting. irrespective of the month of defruiting. The decline after fruit removal was 30‐40% in August or September and 57% in October. After defruiting in August or September, trees respired 50–60% slower in the dark, but 39% faster after defruiting in October. The excessive respiratory losses after fruit removal in October. when the tree lost more carbon than it assimilated. may have been induced by translocation of carbohydrates from the leaves to the perennial woody parts of the tree and by the onset of leaf senescence. Fruit removal in August or September increased water use efficiency by 31–41%. but decreased water use efficiency in October by 75%