Variety Performance is key to profitabilityResearch & Extension
When it comes to profitability, irrespective of which database you look at, the range in orchard and variety performance is astounding. Using AgFirst’s OrchardNet™ database we can assess the performance of the main varieties grown in Australia.
Consistent high yield, with optimum size range for chosen market outlets and high fruit quality, lead to a good profit result.
In the orchard, the key to achieving high levels of yield and quality performance lies in attention to detail. Usually this will mean higher labour costs within the orchard gate, so it’s not a good idea to take the cost-accounting approach to your orchard production costs. We see far more problems where labour input is minimised than we do with labour cost blowouts.
Approximately 70 per cent of within-orchard gate costs are fixed, with only harvesting costs variable and related to yield.
Generally, there is not a lot of scope to improve the bottom line through reducing production costs as, in most orchards, costs are already pared to the minimum.
Raising income offers your largest opportunity to improve orchard profits. For the average orchard block there is plenty of scope to lift yields, class 1 recovery, colour and fruit size.
Table 1 below shows the impact of yield and quality on profit per gross kg, in cents per kg for 2017 crop. The data source is the Australian OrchardNet database.
Profit expressed as cents/kg gross crop across all varieties depends on high yields, high class 1 recovery and a good market return.
High yield with poor class 1 recovery, as shown for Royal Gala (highest yield block), results in a poor return.
In the case of Cripps Pink, there is not much difference in yield between the orchard block showing the most profit per hectare and highest yield block, however, profit per gross kg for the highest yield block is 69.5 cents/kg, where as the highest profit block profit per kg was 83.1 cents. The difference here is packout dropping from 85 per cent with 75 per cent.
Among the varieties, note the gross yield ranges between average production, upper quartile average and highest production (Table 2). On average, upper quartile is 1.55 times average, and highest yields are 2.14 times the average yield. Incidentally, the New Zealand data shows similar trends, but not quite so much spread, which is probably a reflection on our kinder growing conditions and the fact that around 60 per cent of our production comes from one district.
Note that the two local varieties Cripps Pink and Granny Smith have the tightest spread. These varieties are well suited to Australian growing conditions and are therefore more consistent between growers and blocks.
I have not looked at below average performance, however it stands to reason that if the best blocks are achieving twice average, there must be some only making half average.
The other point to note is that average production levels in some varieties have slim profit margins so it will only take a small shift in costs or returns to push them into the red.
Attributes of high performing blocks
A full, uniform fruiting canopy with low tree vigour and regular year-on-year cropping are the main attributes of high performing blocks.
Once full canopy is established, no more than 20 to 30cm average length of annual shoots is needed to maintain a healthy tree and size its crop. Once annual shoots exceed 30 to 40cm in length, photosynthates are being diverted to shoot growth rather than going into the fruit.
Excess tree vigour is one of the main reasons for low yield and quality. There is a very close relationship between branch strength and shoot vigour. Branch gradient, and more importantly branch thickness determines shoot and extension growth length.
Crop load is the best vigour control tool and where vigour is excessive it is difficult to set sufficient crop load for vigour control.
Branches need to be slightly pendant to secure good fruit set. The other point to recognise is that in the case of pomefruit, a shoot sets up a fruit bud on the terminal bud where vigour is under control, but takes two growing seasons to develop fruiting spurs on its lateral buds. With some varieties significant fruit can set on the auxiliary buds of one-year wood, particularly on precocious dwarfing rootstocks. In general, a fruiting unit or fruiting lateral will be in its third growing season before it can carry sufficient crop load for vigour control.
This means that trees need to be far enough apart to allow for at least two years lateral extension growth before over-crowding and within-canopy shading impacts on fruit set and fruit quality.
In recent years it has been the fashion to plant orchards at very high tree densities, often less than a metre between trees. Once plantings get down to these densities the longest fruiting lateral you can have in the lower tree is not much more than 60cm length. In the upper tree you still need separation between trees to allow good light penetration into the lower half of the tree, so the top half of the tree needs fruiting spurs rather than laterals.
We are also finding that multi-leader systems are giving calmer trees than single leader trees. This is particularly so for grafts. I think this is because we can develop a larger fruiting canopy sooner with a multi-leader tree than a single leader.
Incidentally, the critical branch strength relationship for vigour and cropping is a branch diameter of about 2cm per metre of fruiting lateral length. Branches need to be 20° to 30° below the horizontal. If any more pendant than this, shading of their fruit becomes a problem.
Upper tree management
The most cost-effective pruning, thinning and picking is that which can be done easily from the ground, or off a short ladder. This means that most of your fruitful tree canopy needs to be between about 75cm above ground and 2.5–3m height in the tree.
As intensive orchards mature, shade out of the lower tree becomes a problem. This is largely due to allowing the upper tree branch structure to become too large, or retention of excessive branch numbers in the middle, lower tree.
Leaning trees lead to significant lower canopy shading too, so its necessary to provide very good upper tree leader support.
In the upper tree, right from an early age, potential high vigour laterals and branches need to be identified early before they become problems and either removed completely, snapped over or stubbed back to 6 to 8 buds in early summer, or tied down.
Where upper tree leader extension growth is strong, heading the leaders back after fruit set in November, or early December, is a good way to bring upper tree vigour under control.
Specific variety management
Unless you have a site that colours fruit well, the standard strains of this variety are now past their use by date.
For good colour in standard strains the site needs to be almost nitrogen deficient, however if nitrogen levels become too low, yields will be very low as well. Many growers leaf pluck to improve fruit colour however this is expensive and can impact the following years crop if overdone.
Red strains colour well before the fruit becomes over mature, which reduces fruit handling injury and improves storage. Red strains have very high productivity with good class 1 packout potential. Generally, the market is unwilling to pay sufficient premium for high colour standard strains once improved red sports become available.
The tree is very vigorous when young and has a stiff upright growth habit, so branch training is necessary before the branches stiffen. Cripps Pink is very responsive to reflective mulch and has low susceptibility to biennial bearing.
Making this variety perform is a real challenge. Fruit size is naturally large, one of the attributes of a cultivar with high yield potential, however orchard experience shows it’s very difficult to achieve regular high yields year on year.
In the absence of sufficient crop, tree vigour is high. Unlike many varieties, Fuji lacks the ability to flower and set fruit well on auxiliary buds on one-year wood. This delays cropping on young trees, leading to an extra season’s growth before cropping will kick in for vigour control.
High performing, regular cropping blocks have large, low vigour canopies, with many short laterals, 15 to 20cm long, terminating in fruit buds. Where tree vigour is excessive, strong annual shoot growth can abort fruiting sites. Trunk girdling in the post bloom period is a good tool for overcoming this problem.
Fuji is very prone to biennial bearing and needs careful thinning management to avoid this problem. Fruit quality, particularly poor fruit colour and sensitivity to sunburn injury is increased by excessive crop loads.
Good fruit colour requires adequate light exposure and low nitrogen status. Older strains are difficult to colour and generally incapable of meeting market fruit colour specification.
High colour strains are now available in both stripe and blush colour forms. These strains are rapidly replacing standard strains.
For high class 1 recovery, the crop needs to be grown as spaced singles.
Fruit set is very sensitive to low nitrogen levels during flowering – fruit set period, so there needs to be adequate nitrogen at this time, but low nitrogen levels near harvest to maximise fruit colour. It is very responsive to reflective mulch.
Birds love it, so it needs good protection from birds near harvest.
Fuji crops best on weak pendant, low vigour wood, needs growth regulators such as ethephon or NAA in the summer period to improve return bloom and is prone to magnesium deficiency which becomes more severe as crop load increases. Foliar magnesium sprays may be necessary to avoid severe magnesium deficiency and leaf drop.
It is difficult to thin with chemical thinners, particularly if the bloom period is extended.
The OrchardNet™ database shows Granny Smith is a high performer under Australian growing conditions. It performs well in most growing areas. Being a green variety, it does not require good light or colour, however it still needs adequate light through the canopy for good fruit set, fruit size and satisfactory eating quality.
Sunburn and sun tinting are the main fruit quality issues. Overhead netting solves these problems.
Prone to handling damage, particularly if harvested late.
Being a green variety, Granny Smith has a higher appetite for nitrogen than other apple varieties and good nitrogen fertiliser programmes keep the fruit green and often lead to larger crops. Sensitive to calcium chloride foliage injury so calcium nitrate is the preferred calcium foliar product.
Prone to tree pit, so needs a foliar calcium spray programme to minimise this disorder. Trees can be excessively vigorous if on stronger rootstocks. As with other varieties, good vigour control is the key to high yields. Granny Smith crops best on relatively weak pendant branches.
Prone to wind rub injury to fruit and exposure to high winds near harvest can cause heavy fruit drop due to its weak stem which can pull out of the fruit. Normal stop drop sprays which strengthen the abscission layer between the fruit stem and spur are ineffective on Granny Smith.
Royal Gala, and particularly its better high colour strains, has become a very important variety worldwide.
Climatically it’s very adaptable and grows well under a wide range of conditions.
The tree has moderately high vigour so now is generally planted intensively on precocious dwarfing rootstocks.
Its natural fruit size range is moderately small, with average fruit size about 155g, however it is possible to produce an average size of 165g without sacrificing its yield performance too much.
Royal Gala gives a very good response to ethylene blockers such as Harvista® and Retain® and with these tools its possible to delay harvest by 10 to 14 days. Providing the trees are not over cropped, or under too much environmental stress fruit sizing continues through harvest at about 1 per cent weight increase per day.
The Australian OrchardNet™ database shows that the upper quartile average yield is 50 per cent higher than the data base average, and the highest yields are more than twice average yield so there is a lot of potential in Australia to increase Royal Gala yields.
Royal Gala has a relatively upright growth habit without crop load and young trees can be vigorous. Managing tree vigour is the key to getting high yield performance from it. Excess tree vigour competes strongly with fruit for photosynthates. Where there is high vigour, fruit size is often smaller than where there is weak to moderate tree vigour.
As this variety was developed in a mild summer climate, it does not like high summer temperatures. It is sensitive to sunburn injury and in some hot climates lenticel breakdown injury to the fruit can occur during storage.
The fruit has a long stem so it is possible to grow it in bunches of doubles and triples.
In mild climates biennial bearing is not generally a problem. Where it is exposed to excessive summer heat stress, biennial problems increase.
Very responsive to reflective mulches in the preharvest period and these are widely used, even with some of the high colour strains.
While it can be stored from one year to the next, eating experience falls off rapidly after four to five months storage.
Relative to many varieties its very grower-friendly.
Under net, provision for good cross pollination is necessary.
Susceptible to Alternaria leaf necrosis and often can show heavy leaf shedding, particularly on over vigorous young trees
This is a relatively new variety to Australia, so a lot of blocks have yet to reach full production.
In many respects Scifresh (Jazz®) behaves very similar to Nicoter (Kanzi®) as they both have the same parentage.
Young trees can be very vigorous and may produce strong upright shoot growth which is likely to become bare wood if vigour was too strong.
Unlike Nicoter, fruit size is smaller than optimum for the market. Normal fruit size averages around 160g. With careful tree management 170g average fruit size is possible. As the variety is very prone to calcium disorders its unwise to try and grow Scifresh fruit much larger than this average size.
Crop load does not appear to have a great influence on fruit size. Bud position, bud quality and tree vigour have much greater influence than crop load.
Terminal buds of short annual shoots give largest fruit size, followed by strong spur wood. Fruit size on auxiliary buds of one-year wood is usually 30 per cent smaller than terminal bud fruit.
Scifresh is very prone to calcium disorders of bitter pit and lenticel blotch pit. It needs to be grown in a soil with good cation balance. Base saturation for calcium needs to be above 70 per cent, magnesium 8 to 12 per cent and potassium only 3 to 4 per cent to minimise bitter pit risk.
Tree vigour needs to be low, and an intensive calcium spray programme is necessary.
Mature Scifresh is moderately prone to biennial bearing, so needs good early fruit thinning programmes backed up by summer growth regulator applications to improve return bloom.
Inadequate nitrogen levels over the flowering fruit period also weakens fruit set.