Aims: Climate, soil water potential (SWP), leaf relative water content (RWC), stomatal conductance (gs), fruit and shoot growth, and carbohydrate levels were monitored during the 2008 and 2009 growing seasons to study the responses of 'Gala' and 'Fuji' apple trees to irrigation placement or volume. Methods: Three irrigation treatments were imposed, conventional irrigation (CI), partial root-zone drying (PRD, 50% of CI water on one side of the root-zone, which was alternated periodically), and continuous deficit irrigation (DI, 50% of CI water on both sides of the root-zone). Results: After each irrigation season, DI generated twice the soil water deficit (SWDint) than PRD (average of dry and wet sides) and a greater integrated leaf water deficit (LWDint) than PRD and CI. Both PRD and DI reduced gs by 9 and 15% over the irrigation period. RWC of both PRD and DI was directly related to SWP and inversely related (non-linear) to vapor pressure deficit (VPD), whereas it was unrelated to gs. Considering individual sampling days, gs of 'Gala' leaves was inversely related to VPD mainly until early August (fruit at cell expansion phase and high VPD), while it was directly related to VPD in September (no fruit and low VPD). On the contrary, gs of 'Fuji' leaves was inversely related to VPD from late August until mid October (low VPD and fruit at cell expansion phase). Fruit growth was not affected by irrigation, whereas shoot and trunk growth was reduced by DI. Irrigation induced sporadic and inconsistent changes in carbohydrate contents or partitioning, with a general tendency of DI leaves to degrade and PRD to accumulate sorbitol and sucrose in dry periods. Conclusions: 'Gala' trees exhibited a more conservative water use than 'Fuji' trees due primarily to different timing of fruit growth and crop loads. Different levels of SWDint, rather than changes in stomatal control and carbohydrate partitioning, seem to play a major role in determining a better water status in PRD than in DI trees.

Lo Bianco, R., & Francaviglia, D. (2012). Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: Placement versus volume effects. PLANT AND SOIL, 357, 41-58 [10.1007/s11104-012-1149-z].

Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: Placement versus volume effects.

LO BIANCO, Riccardo;FRANCAVIGLIA, Davide
2012

Abstract

Aims: Climate, soil water potential (SWP), leaf relative water content (RWC), stomatal conductance (gs), fruit and shoot growth, and carbohydrate levels were monitored during the 2008 and 2009 growing seasons to study the responses of 'Gala' and 'Fuji' apple trees to irrigation placement or volume. Methods: Three irrigation treatments were imposed, conventional irrigation (CI), partial root-zone drying (PRD, 50% of CI water on one side of the root-zone, which was alternated periodically), and continuous deficit irrigation (DI, 50% of CI water on both sides of the root-zone). Results: After each irrigation season, DI generated twice the soil water deficit (SWDint) than PRD (average of dry and wet sides) and a greater integrated leaf water deficit (LWDint) than PRD and CI. Both PRD and DI reduced gs by 9 and 15% over the irrigation period. RWC of both PRD and DI was directly related to SWP and inversely related (non-linear) to vapor pressure deficit (VPD), whereas it was unrelated to gs. Considering individual sampling days, gs of 'Gala' leaves was inversely related to VPD mainly until early August (fruit at cell expansion phase and high VPD), while it was directly related to VPD in September (no fruit and low VPD). On the contrary, gs of 'Fuji' leaves was inversely related to VPD from late August until mid October (low VPD and fruit at cell expansion phase). Fruit growth was not affected by irrigation, whereas shoot and trunk growth was reduced by DI. Irrigation induced sporadic and inconsistent changes in carbohydrate contents or partitioning, with a general tendency of DI leaves to degrade and PRD to accumulate sorbitol and sucrose in dry periods. Conclusions: 'Gala' trees exhibited a more conservative water use than 'Fuji' trees due primarily to different timing of fruit growth and crop loads. Different levels of SWDint, rather than changes in stomatal control and carbohydrate partitioning, seem to play a major role in determining a better water status in PRD than in DI trees.
Settore AGR/03 - Arboricoltura Generale E Coltivazioni Arboree
Lo Bianco, R., & Francaviglia, D. (2012). Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: Placement versus volume effects. PLANT AND SOIL, 357, 41-58 [10.1007/s11104-012-1149-z].
File in questo prodotto:
File Dimensione Formato  
PreRevManuscript.pdf

Solo gestori archvio

Dimensione 6.6 MB
Formato Adobe PDF
6.6 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10447/65835
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 23
  • ???jsp.display-item.citation.isi??? 18
social impact