The effect of summer pruning and calcium foliar spraying of 'Jonagold' and 'Sampion' apple trees on fruit storage quality.

摘要

In trials in Poland in 1994-96, 4-year-old Jonagold and Sampion apple trees on M.26 rootstock were subjected to the following treatments: shoot pinching 3 times (in June, July and August), shoot pinching twice (in June and July), shoot pinching twice (in June and July) restricted to tip leaves, or spraying 4 or 6 times with 0.5% CaCl2 (in June and August). Control trees were untreated. The first 2 pinching treatments decreased mean fruit weight and yields per tree in the third year when compared with the control. Shoot pinching 3 times (in June, July and August) increased the N content of the fruits. No pruning treatment affected K or Mg contents. The effect of summer pinching on Ca and P contents was statistically insignificant. Fruits from the trees subjected to 2 pinchings and 4 sprays had less bitter pit after 85 days of storage at 2deg C and 85% RH than fruits from the other treatments and the control.