Preliminary evaluation of storage protocols for long term storage of the Armagh Bramley, post DPA

Sean Mac an tSaoir, john Mansfield, Frances Ward and Suzanne Johnston, AFBI horticulture Loughgall.

Following the loss of DPA the NI apple industry was left with no alternative storage protocols. Whilst some low oxygen stores did exist, they had not been used as such. To address the information deficit a range of experiments were undertaken by AFBI Loughgall in partnership with the local industry.

Extended storage of Bramley in controlled atmosphere storage with DPA is not possible. However as alternative methods for ethylene control became available, the opportunity of combining the Smartfresh (SF) treatment with an additional ethylene removal system became possible. It was

therefore decided to establish the Smartfresh treatment in Loughgal store 1 with Smartfresh plus Fresh Extend Ethylene scrubbing via Bion Potassium permanganet granules. In addition apples from the same orchards were also placed in Ultra low oxygen stores. The experiment started on 8th September 2013 with all apples treated with Smartfresh within 7 days of picking. With the rise of ethylene levels recorded (Fig. 1) the stores were opened on the 24th June 2014.

Ethylene levels increase as the Smartfresh (SF) treatment wears off and this result in the controlled atmosphere store having to be opened.

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Fig 1. Ethlene production by Armagh Bramley under different storage regimes 2013–2014

24 Jun5 Nov0

5

10

15

20

25

30

35

40

45

50

12 Dec 14 Jan 5 Nov 11 Mar 20 Mar 8 Apr 30 Apr 27 May

Key

SmartFresh (SF)

SmartFresh + ethylene scrubbing (es) (Bion granules)

ULOEth

ylel

e le

vels

(pp

m)

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Pressure (Kg) SmartFresh SmartFresh + Bion Granules

08/09/2013 12.7 12.1

26/06/2014 9.15 8.93

% Loss 28 26

Bin Weights (Kg) SmartFresh SmartFresh + Bion Granules

08/09/2013 372 380

26/06/2014 361 369

% Loss 3.0 2.9

A B C D

SF 8 7 29 11

SF+ES 7 9 24 8

ULO 2 3 8

Table 1. Fruit quality changes during the storage period (mean of six orchards)

Table 2. The effect of storage regime on fruit loss (%) from 4 orchards after 10 months storage

Since the DPA storage problem arose, further complications regarding the classification of diseases also developed. Fusarium species were recorded which had not been noticed before. In addition, it was very difficult to determine the primary cause of fruit rot after 10 months in storage. Therefore, whilst the diseases were classified visually, the results were pooled (Table 2) to provide an overall evaluation of loss.

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It is obvious from table 2 that the low oxygen storage system reduces disease development compared to the controlled atmosphere regimes. The data also illustrates the importance of selecting quality fruit in the first instance (sample c had been, included in the experiment by mistake and should not have been used for long term storage).

When the stores were opened at the end of June (this is common in commercial stores to have samples of fruit), scald was not a major issue in any of the samples; although it is obvious that it was starting to develop in the SmartFresh only store.

Summary

Overall, controlled atmosphere storage combined with Fresh Extend ethylene scrubbing enabled Bramley to be stored for 10months. However, several issues emerged from this work which require further investigation. The disease spectrum of the fruit appears to be changing and quality management of the fruit prior to harvest has become even more critical. All the storage systems reduced disease development; however, post storage these diseases developed very rapidly.

Table 3. The effect of the storage regime on the development of scald (expressed as %) in fruit from four different orchards.

A B C D D+4 weeks

SF 0 3 15 7 33

SF+ES 0 0 4 0 3

ULO 0 0 0