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Back in November we predicted from the early flowering, heat unit accumulation and rate of initial fruit sizing, the Royal Gala harvest period here in Hawke's Bay would be around 7 to 10 days earlier than normal. For standard rootstocks without any manipulation of bud break or girdling, to advance maturity, we thought harvest would begin somewhere around 8th to 10th of February. Many blocks we were gathering data from made initial skim picks around the 8th or 9th of February, and were well into a major pick by 11th February.
From the compressed flowering periods we saw this spring, we also forecast that the harvest period would be short and sharp. In some blocks, it looks like it will be 10 to 14 days from start to finish.
Historical records from Hawke's Bay show that opening dates for Royal Gala over the period 1993 to 1997 have ranged from 15 February at the earliest, to as late as 23rd February. Since 1997 objective maturity monitoring on a block by block basis has been used to determine starting date so there has been more diversity in opening date, depending on rootstock, thinning regime and dormancy manipulation.
Pears have also been early, with estimates of about 14 days ahead of normal for Doyenne du Commice and Taylors Gold.
Impact on Later Varieties
The big question now is 'will the early harvest we have seen in these early to mid-season varieties carry on to the later varieties?'. From what I have seen, I think there will be some maturity advancement in Braeburn, but probably less in Fuji.
Pacific Queen and Pacific Rose are both looking more advanced than usual for this time of the year.
Historical opening dates for Braeburn have ranged from 15 to 24 March and Pacific Rose from 28 March to 11 April. Fuji has ranged from 20 March to 4 April.
In the light of the earlier variety experience this season, it would appear prudent when applying pesticide sprays close to harvest to be prepared for some harvesting of these other varieties around 7 days ahead of normal. This would suggest during the week starting 11 March for Braeburn, and perhaps the week starting 18 March for Fuji.
It is probably not quite so critical to forecast accurate go dates for these later varieties because their maturity does not race quite so much as the earlier varieties once the maturity starts moving.
We should also get some early warning as to what is happening with these varieties from the behaviour of Hicaned blocks in Gisborne. Incidentally, a large proportion of the Gisborne Royal Gala which had been Hicaned was already harvested by 11 February.
Like the Royal Gala, we can expect harvest windows for later varieties to be short.
Other Harvesting Issues
In addition to maturity concerns, we also have to worry about inherent vice risks, particularly with Braeburn.
This year the Braeburn has quite a lot of tree-to-tree and block-to-block variability in tree vigour and crop load.
Where crops are light and vigour high, we can expect to have problems with bitter pit in storage and in some instances also Braeburn Browning Disorder (BBD). In some light cropping high vigour Braeburn blocks, tree pit is already showing up. Harvesting of such blocks for export could be inviting clawback problems. Where there is considerable variation in crop load and vigour among the trees in a block, trees need to be classified on the basis of crop load. The fruit from those in the bottom group that are already showing tree pit needs to be diverted straight into the juice factory.
Very heavy trees in the block will probably have good fruit calcium levels, but could give some trouble with shrivel from later harvested fruit.
In the middle between these two cropping extremes will be a range of trees with low to moderate crop loading and tree vigour levels where the hard decisions have to be made in regard to management of inherent vice. Grouping trees within this range on the basis of vigour and crop load and having fruit analysed for calcium from these groups may help determine the cut off point in regard to crop load below which the risk of inherent vice problems becomes too great.
Holding marginal fruit in store for a few weeks prior to packing and at harvest or just before harvest taking a sample of fruit from it for ripening prior to packing may give some feel for its likely storage behaviour. One technique developed by Bangerth was to harvest apples about 14 days before normal harvest, dip in 2,000 ppm ethephon (40 ml Ethrel/10 l water), then hold for two weeks at 20 degrees celsius. Samples showing pt in this test would indicate lines of fruit with risk.
Both Fuji and Pacific Rose are showing premature ripening already where apples are showing internal rots. Some of this problem has also been noted in Royal Gala, which suggests levels of core rots may be above normal this year. Several weeks before harvest of these varieties, affected fruit develops very bright colour and can be easily removed from the crop by thinning it off at this stage.
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