Articles
INTENSIFICATION TRIALS OF CANINO APRICOT ORCHARD
An apricot plot of 5 rows 40 m long, was planted in 1976 (Table 1) with spacing of 1.5 m (between rows) × 0.75—1.0 m (within rows), having about 6 000—9 000 trees per hectare.
The original meadow orchard system, which had been proposed for apples 11 years ago at Long Ashton, has not succeeded on the Canino apricot despite its vigour and early bearing capacity, mainly due to slow regeneration in comparison with some peach varieties after cutting off the tree at harvest time.
Summer pruning has a prolonged effect on apricot trees, so the terminal growth remains 40—60 cm long, compared to 80—120 cm shoot length a year after winter pruning.
Therefore, we preferred a training system of a modified central leader with 3—6 limbs pruned back alternatively after 1—3 bearing seasons.
Vegetative shoots sprout and replace the old branches.
Three-year-old trees reached the height of 2—2.5 m with winter pruning, or 1.5—2 m after additional summer pruning (Table 2 a). Their yield was 3—5 kg per tree, or 25—33 tons per hectare.
Fruit could be picked easily, due to flexible branches of the young apricot trees.
At the narrower spacing, tree canopy became too dense, leading to failure of the lower parts to initiate flower clusters, while the fruits of central parts grew slower and were inferior at harvest.
Therefore, we added hedging and shoot thinning the fourth winter.
Fruit set was poor the following spring, inspite of a dense and uniform flowering due to late mineral-oil spray and a hail storm during blossom.
Variation in timing and dosage of this treatment may lead to an earlier but light crop, or to a heavy crop and late ripening.
Yield per tree reached 2.8 kg in the fourth season after alternate winter pruning, but only 1.7 kg in winter-topped or summer pruned trees, which were picked earlier, having the same yield on densely spaced rows; the yield per hectare being 19 and 13 tons (respectively). Fruit set of the fifth spring (1980) was much higher due to age, better management and weather conditions, and yield increased accordingly (Table 2 c). 1981 crop was lighter again (2 kg/tree or 15 tons/ha) after