‘Aurora Golden Gala™’ Management Options

The ‘Aurora’ apple is a high quality yellow skinned dessert apple that is grown in B.C. to an attractive high quality fruit with a 6 – 7 month storage life and good shelf life. Test trees of Aurora have been planted in Ontario by a number of growers. It matures in Summerland (B.C.) approximately 145-155 days past the 90% king bloom stage of bud development. The tree has an excellent growth habit and is highly suitable for high density apple culture. Under North East and specifically Ontario growing conditions, ‘Aurora’ can have a tendency to be small, green and squatty in shape when grown without any special treatment. Fruit quality on younger trees appears to be generally poorer when compared to more established trees.

A small-scale trial was installed in 2006 at the Birnam cultivar trial site in Lambton County to investigate whether or not a program using Promalin containing BA and the gibberellins A4 and A7, and the particle film known as Surround Crop Protectant would have any influence on the size and finish of this cultivar grown under Ontario conditions.

Promalin was applied 3 times at label rates starting at petal fall and followed by a summer program of Surround applied 6 times from early June to the middle of August. Treatments were applied to individual apple trees on M9 rootstock in their 4^th leaf in a replicated plot design. All trees in the trial were managed by chemical thinning and sprayed according to accepted IPM standards.

Trees treated with Promalin (3 applications) during the fruit-set period and Surround Crop Protectant during the summer produced fruit that averaged 182 grams in weight, were very typey and had a silky smooth lemon yellow finish. Control trees produced fruit that averaged 151 grams weight (Figure 2), were very squatty in shape and greenish in colour. See attached photo, Figure 1. This treatment regime for Promalin/Surround appears to enhance the performance of young ‘Aurora’ trees, in the absence of more mature trees to compare with. 

In discussing this cultivar with Dr. Cheryl Hampson (AAFC, B.C.) the emphasis in crop culture of ‘Aurora’ in B.C. is on early thinning for best fruit size and finish. 

‘Aurora’ should be harvested in a single pick, based on starch degradation between 4 and 5 on the Cornell generic starch chart. If fruit are left on the trees too long into the maturity cycle they could get waxy and some stem-end cracking could develop. 

According to the folks at PICO who have been working to establish Quality Assurance Guidelines for Aurora Golden Gala™: 

“Picking too early increases finger bruising. Texture retention in storage has not been a problem regardless of pick date and pre-harvest drop is negligible. Leave small or green fruit in the orchard. Fruit from young trees should be separated from fruit from older trees. Young-tree fruit tends to have russet and a more squatty fruit shape. Consider de-fruiting young trees to encourage tree growth. 

Pruning: The tree puts out a large number of fruiting spurs. If using a superspindle system, this can be used to advantage to reduce thinning later, by judicious removal of fruit buds. The trees are less vigorous than Gala, and may need stronger pruning periodically to re-invigorate them. This is particularly true if the tree has been overcropped in the past, or overcropped in its early years. Spur renewal pruning is needed to keep the variety vigorous and productive, and to maintain good fruit size. 

Chemical Aids: The use of ReTain is discouraged. Pre-harvest drop is negligible with Aurora Golden Gala™. The variety can be difficult to pick and the use of ReTain will accentuate this feature, leading to finger bruising. 

Packing House Receiving 

Fruit from young trees should be segregated, as it is likely to have more cosmetic defects. At PARC (AAFC, B.C.) we have successfully stored Aurora Golden Gala™ at 1ºC in air until March or April. Keep Aurora Golden Gala™ away from direct blowing of the cooling system or it may develop some soft scald. Put a bin of Gala or some other non-susceptible cultivar on top of the stack, or cover the top bin with a tarp. 

Grading and Packing 

Storage life of Aurora Golden Gala™ is normally good. Pilot experiments at PARC (Pacific Agri-Food Research Centre) have demonstrated that holding the fruit for 6-8 weeks prior to packing can reduce packing line bruising. Warming the fruit slightly (to 12-15ºC) prior to running it over the line also reduces bruising significantly. Green fruit bruise more and recover poorly. 

The fruit will scrabble bruise. It should be returned to cold storage after packing to allow the scrabble bruising to come out. Early experience in B.C. suggests that this may take longer with Aurora Golden Gala™ than it does for Golden Delicious. 

Consider imposing a cutoff on fruit size e.g. those below 138 to be rejected. Such fruit come from overcropped trees and they taste watery and bland. CA storage regimes have not been worked out. No MCP work has yet been done with Aurora Golden Gala™”.

Figure 1 – Treated ‘Aurora’ trees produced fruit as shown on the left while untreated check trees produced fruit similar to what is shown by the apple on the right. See discussion on Promalin/Surround. These apples are from experimental trees at the Birnam Orchard site.

Figure 2 - % Fruit in Each Size Class cv. 'Aurora Golden Gala' Treated vs Untreated Control (Birnam Orchards, 2006)

Link to Data Equivalent Table

For more information:
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