Abstract:
Different apple scab resistant varieties (table 1) were planted in spring 1983 and 1984 in a separated block of the Research Center of Agriculture and Forestry - Laimburg.
The apple trees were grafted on M9 rootstock and planted at 3.5 x 1.2 m distance.
Since 1983 resp. 1984 the whole block was never treated against apple scab and powdery mildew, only against different insects (aphids, leaf miners, tortrix).
The orchard is situated at 220 m above sea level on soil of medium fertility and equipped with overhead sprinkler irrigation.
The average rainfall in the Adige Valley is about 800 mm with a good distribution during the year.
Yield per tree and year, quality of fruit, growth habit, scab resistance to scab and mildew were evaluated and registered.
Following a brief summary of the present results:
- All varieties presented in table 1 are immune from apple scab (Venturia inaequalis), but not from powdery mildew.
- The flower time of the scab resistant varieties is normally prior to Golden Delicious (early till middle early flower time) and lasts very long (favourable for impollination!).
- Florina is the variety with the highest yield, while Fumos de Voinesti, Coop 12 and Coop 6 are the lowest in production.
- Flesh firmness from Sir Price and Coop 6 is very low, Florina and Prima are very firm (table 2), while the last one loses firmness soon after harvest.
Soluble solids and titratable acidity are high and well balanced in the varieties Florina, Sir Prize and TSR 29T219, while Prima and Red Free have more acidity.
- Sensory evaluations with standard varieties are showing that Florina and TSR 29T219 in the "external appearance" and "taste" are classified as good to very good in comparison to Gala, Royal Gala, Fuji, Braeburn (tables 3a, 3b). TSR29 T219 has a lower flesh firmness.
- Considering the yield, fruit appearance, external and internal quality the following sex tested varieties seem to be very interesting: Prima, Red Free, TSR 29T219, Sir Prize, 1640–101 and particularly Florina.
They do not require fungicide sprays against apple scab and only reduced sprays for mildew.
This in the future reduces production costs for both, sprays and work.
- Till now Florina is one of the best scab resistant varieties.
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