VERY IMPORTANT: 'Bigbucks' should be harvested on physiological maturity; not on colour. Harvesting 'Bigbucks' fruit immaturely will have a negative impact on both the eating quality of the fruit and will compromise the name of 'Bigbucks'.
Planting and cross–pollination
Rootstock and planting distance / orchard system choice is as with 'Royal Gala'. Aim to plant with magnetic north as row direction. If this is not possible, aim to stay between true north and 30º west of true north.
Use 'Granny Smith' or 'NIVV Golden Delicious' as cross pollinators. Either 1 in 10 (10%) or 1 in 9 (11.1%; every third tree, every third row).
The use of GA4/7+6-BA
I.E. PROMALIN, PERLAN, ETC.
Trial work on 'Bigbucks' has indicated that a 125ml/100lit GA4/7+6-BA (i.e. Promalin or similar) application at 40% of TRV between full blossom and three days after full blossom is beneficial to fruit shape. The application has led to attractive slightly elongated fruit without excessive typiness. Experience indicated that a second application of GA4/7+6-BA did not have additional beneficial effects.
Remember that an early GA4/7_6-BA application may have a thinning effect. On trees carrying their first commercial crop or in orchards with a high population of lateral fruit on 1 year old wood, use a lower dose of 62.5ml/100lit GA4/7+6-BA at 40% of TRV between full blossom and three days after blossom.
Thinning and crop load management
Experience on the chemical thinning of 'Bigbucks' will grow over time. Thinning decisions should be similar to that of 'Royal Gala'. Note that an early GA4/7+6-BA application as described above may have some thinning effect in itself.
6-BA (i.e. Maxcel, Excillis or similar) can be used at ± 8mm fruit size to thin within bunches. This may be followed by an application of carbaryl (i.e. Sevin XLR or similar).
Chemical thinning lowers the number of generations of fruit on the tree and has a positive effect on in-tree variation in harvest maturity.
Do not overcrop your 'Bigbucks'. A healthy leaf to fruit ratio is conducive to excellent quality and buffers the tree and fruit to environmental stresses.
Retain® and Harvista™ use
Philagro SA conducted research regarding the use of Retain® (AVG) on 'Bigbucks' during the 2018/19 season. All treatments had a marked positive effect on fruit pressure. Earlier applications caused a more pronounced delay in starch breakdown than late applications.
Unlike with poor colouring sports of 'Royal Gala' where Retain® is applied 8-10 days before anticipated harvest, indications are that the optimum application time of Retain® on 'Bigbucks' will be somewhere between 21 and 28 days before anticipated harvest. The research will be repeated this season.
The use of Harvista™ on 'Bigbucks' has not been investigated to date, but expectations are for a positive result.
Determining 'Bigbucks' Harvest Protocol
'Bigbucks' apples are already full red 2-3 weeks before optimum maturity. Due to its full red colour, the background colour is virtually invisible and growers can make the mistake of harvesting too early. In striped Galas the background colour is a useful indicator of maturity; not so with 'Bigbucks'.
Starting 14 days before anticipated harvest, the fruit maturity and extent of variation within the orchard should be assessed through iodine testing of starch breakdown. Select and mark representative trees within the orchard; if it is a large orchard or one that lacks uniformity, more trees should be selected. On fully grown trees, collect seven fruit samples from each tree according to the spatial categories A-G as displayed in the figure below. On young trees less categories will suffice.
Once samples have reached 8/10 within the 20%-40 starch breakdown range, commence harvest of fruit located in those categories. In orchards with good light distribution it is possible to strip pick 'Bigbucks'. In orchards with sub-optimal light distribution through the canopy one can expect two harvest events. Areas with comparable light distribution are expected to have comparable physiological maturity. Prohexadione-Ca (i.e. Regalis or Kudos) and judicious summer pruning can be used to assist in maintaining a uniform light environment throughout the canopy.
Very important comparison
|Older Gala strains||The decision whether to pick or not is, in essence, left to each picker. They have to decide themselves whether an apple is harvest ready or not, based on background colour. This leaves massive room for error.|
|Bigbucks||In the case of 'Bigbucks' the pickers can focus on picking the fruit correctly and carefully. The owner/manager/advisor must make the call on when to pick which fruit. If this responsibility is handled correctly, one can expect fewer maturity issues with 'Bigbucks' than older strains.|
It is recommended that 'Bigbucks' should be handled post-harvest in a similar way as normal 'Royal Gala'. The use of 1-MCP (Smartfresh) is recommended as per the 'Royal Gala' protocol. If environmental stresses or adverse conditions, like drought or a heat wave, occurred during the harvest window, it is recommended to delay packing by 14 days from date of harvest. Due to its superior colour, 'Bigbucks' can hide blemishes at harvest, therefore delaying packing will allow any defects such as heat damage to show more clearly.