International apple and pear research update – August 2015

Compiled by Dr. Gordon Brown

Research snippets are sourced from abstracts of published scientific papers collated in the CAB direct database. To get the abstract related to any snippet please contact Gordon Brown on or 03 6239 6411.

Nurseries and new varieties


Thermotherapy followed by shoot tip grafting resulted in a 66% elimination rate for viruses.

United States of America

Apple rootstocks were tissue cultured under red, blue or white light and it was found that red light increased the number of elongated shoots of B9 and G30.


Comparing the graft union of Conference or Williams pears on quince indicates that incompatibility is due to increased levels of reactive oxygen species (oxidants) or a less efficient detoxification system.



A five year trial found that a single, early spring application of the organic nitrogen fertilisers Azocor 105 or compost + Nutristart provided equivalent yield of apples to sulphate of ammonia.


Research suggests that apple flower buds are hydraulically isolated from the stem during winter until a few days before bud burst indicating that climate effects are related to a whole shoot effect rather than individual buds.


Sunburnt Fuji skin has elevated levels of oxidants and reduced levels of flavonoid synthesis.

United Kingdom

Flowering strips, planted between apple rows, showed that flowers with long tubular corollae enhanced bumblebee populations and open nectar flowers promoted predators in the orchard.


Studies of pears growing in different soils have identified that salty soils increase fruit acidity, shallow sold increase flesh firmness and sugars, and salty and shallow soils have smaller fruit.



Three apple cultivars were stored at different temperatures and a combination of SmartFresh and DCA resulted in fruit that were firmer than fruit stored at 2°C under Ultra Low Oxygen.


An economic study identified that apple picking, storing and then bulk marketing is not profitable compared to picking and immediate sale or pick, store, grade and pack.


Dipping pear fruit in sodium bicarbonate plus potassium sorbate preserved fruit for 90 days of cold storage and five days at room temperature.

United States of America

Research suggests that the dynamics of auxin levels in apple fruit may be a key factor influencing the timing of ethylene production.

United States of America

As maturity of Bartlett pears progresses they become less responsive to SmartFresh application.


Cloudy apple juices that have not been centrifuged have substantially higher levels of healthy compounds.


Conference pears subjected to 0.3%O2 for 2 weeks and repeated a week later, after 13 weeks of storage had less scald than SmartFresh treated fruit.


A new bioyield device has been built to non-destructively measure fruit firmness which gives equivalent results to the standard fruit penetrometer.

Pests and diseases


Products containing granulovirus for moth control require protection against ultraviolet radiation in order to remain active.


Apple mite pests are problematic in orchards that have been cultivated due to low numbers of predatory mites.


Tank mixtures of copper and carbonates, for black spot control, reduced the protective effect and rain fastness of copper products and reduced the curative effects of the carbonates.

United States of America

Brassica seed meal incorporated into the soil provides control of apple replant disease for several seasons longer than soil fumigation with Telone/ chloropicrin mixtures.


Cladosporium cladosporioides H39 is an antagonist of black spot and field trials in four countries have shown its application is as effective as common fungicide spray schedules.

By |July 30th, 2015|R&D updates|

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