Articles
LEAF AREA EVOLUTION, LIGHT INTERCEPTION, YIELD AND QUALITY OF FRUITS IN APRICOT TREES (CULTIVAR TIRYNTHOS) TRAINED TO TRANSVERSE Y AND VASE
Trials were carried out in Andriace, Italy (N 40° 20′, E 16° 48′) from 1993 to 1996 on mature apricot plants grafted on Mirabolano seedlings and trained to transverse Y and Vase at planting distances of 1111 p ha-1 and 400 p ha-1 respectively.
Forty days after bud burst, 62% of incident PPFD was transmitted to the bottom of the canopy in plants trained to transverse Y, compared to 74% in those trained to Vase.
When LAI evolution was complete, transmitted PPFD in Y was 22%, whereas in Vase it remained close to the previous values.
The lower amount of radiation transmitted by transverse Y was due to its larger LAI.
The different types of shoots completed their growth at different times: spurs, short fruiting shoots and long fruiting shoots from April to mid May, and watersprouts in July.
Accumulated yield during the years of trials (1993–’96) was 83.1 t ha-1 in Y and 53.9 t ha-1 in Vase.
Fruit size, on the other hand, was smaller in Y than in Vase.
Shortly before harvest, fruits directly exposed to radiation showed a higher concentration in soluble solids (CSS) than those shaded.
At harvest time the fruits on Y often had a higher CSS.
The results obtained indicate that plants trained to transverse Y can better utilize solar radiation and reach higher yields per unit area, whereas plants trained to Vase produce larger fruits.