Abstract:
Sidi-Barket almond and Okinawa peach seedlings and GF 677 peach x almond have been grown in soil with different lime contents to study their resistance to iron chlorosis.
The relationships between lime content and growth parameters (shoot length, foliar area, dry matter and chlorophyl level) have shown that in control soils all the rootstocks had an optimal growth, while Okinawa peach seedings exhibited visual chlorosis symptoms in soils at 10 and 20% of lime, after 30 days of growth.
Sidi-barket almond seedlings grew better in soils at 20% than in soils at 10%. At 30%, the growth has been greatly reduced.
Peach x almond cuttings tolerated 20% of lime and had the same behaviour as Sidi-Barket.
The IPC test was not too reliable because of minor extractible iron levels in soil compared to lime contents.
In stead, a scale based on chlorophyl level has been suggested for iron chlorosis estimation.
The rootstocks showed iron chlorosis symptoms when this level fell to 3 at 4 mg of chlorophyl/g of dry matter.
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