THE INFLUENCE OF POSTHARVEST CALCIUM TREATMENTS ON THE INTERNAL BROWNING OF PASSE CRASSANE PEARS

ISHS Acta Horticulturae 92: Symposium on Mineral Nutrition and Fruit Quality of Temperate Zone Fruit Trees

THE INFLUENCE OF POSTHARVEST CALCIUM TREATMENTS ON THE INTERNAL BROWNING OF PASSE CRASSANE PEARS

Authors:

P. ECCHER ZERBINI, A. SOZZI

Abstract:
Previous studies have shown that internal browning of Passe Crassane pears is correlated with cropping level (Eccher Zerbini, Gorinin and Gasperetti, 1976) and the position of the fruit on the tree (Gasperetti, Gorini and Terzi, 1968). Treatment of the pears with calcium chloride is effective in reducing the disorder when applied to fruit in the orchard or immediately after harvest. The present study was undertaken to establish the extent to which postharvest treatments with calcium are effective in controlling the disorder in pears originating from trees carrying different crop loads or from different positions on the same tree.

The main effects of these three principal factors were significant (p<0.01) while the interactions were shown to be non-significant. The mean percentages of internal browning for each tree factor are given in Table 53.1. Crop

Table 53.1 PERCENTAGE OF PASSE CRASSANE PEARS AFFECTED BY INTERNAL BROWNING AFTER STORAGE FOR SEVEN MONTHS AT 0–1 °C

Position of fruits on tree
Postharvest treatment^*
Heavily cropping
Lighty cropping
Means for treatment
Means for position Low branch
CaCl₂ Water
  0     11.8
23.5  42.0
11.8  26.9
    19.3 High branch
CaCl₂ Water
  6.2  25.6
35.4  52.5
20.8  38.9
    29.8
Means for cropping class
10.8
38.4

*Benomyl added to both calcium chloride and water dips.

load was the most important factor determining the incidence of internal browning in pears stored for about seven months at 0–1 °C. The disorder was approximately 25 per cent less frequent in fruit from the heavily cropping trees than in those carrying only light crops. Since the former trees had twice as many pears, the incidence of internal browning was reduced to about half that in the crop from the lightly-cropping trees. The percentage of fruits with browning was higher in pears taken from the upper branches of the tree than in those from the lower ones. Immersion in 5 per cent calcium chloride (with 0.1 per cent benomyl) solution effectively limited the onset of internal

Presented by Prof. F. Gorini.

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