Growers Throwing Away Healthy Profits
When growers grade out sunburnt fruit they also throw out healthy profits. According to a recent study by agricultural consultant, David Bell, there’s extra profit up to $8,000/ha available from existing technologies.
David conducted commercial demonstrations at six sites in the Goulburn Valley in 2004/05 on apple
varieties Fuji, Granny Smith, Gala and Pink Lady.
The aim was to determine the economic viability of better managing sunburn with Surround WP under
commercial conditions.
Fruit harvested from rows of trees spayed with Surround WP was compared to fruit harvested from
unsprayed trees. David’s economic analysis compared various tree shapes and sizes, which helped validate
the trends.
A visual assessment of the fruit was undertaken at commercial harvest and the apples were assessed
according to the presence of sunburn and the percentage area of sunburn on the fruit: according to the
following rating system.
0 = no sunburn
1 = slight yellowing on exposed side (<5% fruit area)
2 = noticeable yellowing on exposed side (>5% fruit area)
3 = moderate sunburn with pronounced lenticels (some fruit unmarketable)
4 = significant sunburn – fruit unmarketable
In conducting his economic analysis, David made a number of assumptions:
• Application of Surround WP occurred on the basis of Tree Row Volume.
• Fruit with sunburn rating 0 & 1 were of fresh market quality, domestic or export.
• Apples of sunburn rating 2 to 4 were rejected from any markets.
• Apples were packed in 12 kg cartons.
• Any fruit value for juicing has not been included in the economic analysis.
Results
What he discovered was that the application of Agnova Surround WP provided a significant increase in the quantity
of marketable apples for each grower; 19.9% (Rullo), 23.4% (Ahmets), 16.2% (Pottengers), 12.9%
(Maselki), 11.7% (Morey) and 16.5% (Scali).
Surround WP delivered a positive return on investment in all trial sites and varieties tested. The financial
benefit to the grower ranged between $1,330 and $8,033/ha.
David said the net benefit to growers may not stop there, with additional savings in packing, handling and
storage.
Extra sunburnt fruit removal from the nil treatment meant more people had to be employed on the grading
line. For every 100 untreated apples that go past these workers, 18 apples on average would need to be
removed.
For the Surround WP treated crop, only 6 apples on average would need to be removed and this offered a
significant labour saving, with less people needed to sort fruit.
And there were also savings on handling, dipping and cool storage.
For the unprotected apples, with every 100 bins dipped and cool stored, a total of 18 bins could ultimately
be graded out because of sunburn ratings of between 2 and 4.
Whilst the Surround WP treatment would contain a total of only 6 bins containing the equivalent poor
quality fruit.
This cost saving alone could approach $70 to $80 per bin of apples (figures obtained from the Northern
Victorian Fruit Growers Association and a Western Australian fruit grower).
David said, “Granny Smith apples in particular are very prone to sunburn scald during cool storage.
Sunburn damage can be heightened through cool storage.
“The longer the fruit is kept and the higher the concentration of scald control chemical, the worse the
symptoms become.”
17-Aug-2006