The effects of partial rootzone drying (PRD) and rootstock vigour on dry matter accumulation and partitioningamong leaves, shoots, fruits, frame and roots of apple trees (Malus domestica Borkh. cvar Pink Lady) wereinvestigated in 2005 near Caltavuturo, in Sicily. In a first field trial, trees on MM.106 rootstock were subjectedto: conventional irrigation (CI), maintaining soil moisture above 0·80 of field capacity; PRD irrigation, wherealternating sides of the rootzone received 0·50 of the CI irrigation water; and continuous deficit irrigation (DI),where 0·50 of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9or MM.106 were subjected to CI and PRD irrigation. In trial 1, dry matter accumulation was markedly reducedby DI irrigation and to a lesser extent by PRD; PRD trees partitioned 20% less to leaves, 31% less to fruits and 24%more to woody components than CI trees; DI trees partitioned 14% less to current shoots and 18% more to fruitsthan CI and had the highest fruit:leaf ratio. In trial 2, there was no interaction between rootstock and irrigationtreatments. MM.106 induced greater leaf, shoot, frame and root dry weights (DWs) than M.9, resulting in morevegetative growth and larger trees. PRD reduced leaf, shoot, frame and fruit DWs, while root DWs were similar toCI, and thus PRD trees were 18% smaller than CI trees. Neither rootstock nor irrigation affected dry matterpartitioning among organs or root:canopy ratio, whereas PRD trees or trees on MM.106 showed better wateruse efficiency than CI and M.9, respectively. The results show that PRD trees did not activate drought tolerancestrategies in terms of dry matter allocation that could improve acquisition of water resources, regardless ofrootstock. PRD irrigation increased above-ground dry matter partitioning towards woody components at the expense of leaves and fruits.
|Numero di pagine||12|
|Rivista||JOURNAL OF AGRICULTURAL SCIENCE|
|Stato di pubblicazione||Published - 2012|
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