Technical Evaluation

Annual report 2012 cover web SquareMcGrath Nurseries Ltd have gathered a large body of technical information on Plumac c.v.  In fact, we believe it is the most researched apple ever prior to release. 

We have data on  nursery production, all aspects of cultivation and growing including pruning, training, chemical thinning, disease resistances and susceptibilities, as well as considerable data on productivity, harvest parameters and management, maturity indexes (including colour charts for growers) and storage including air storage, CA and MCP responsiveness, and market and consumer testing.

Whilst some of this information is outlined below, full reports are proprietary property and available to growers only.  Intending growers may access these reports upon signing a Confidentiality Agreement available through McGrath Nurseries Ltd, Contact Us.

Crop Load vs. Colour:

Crop load influences fruit quality and tree performance. Relationships between crop load and fruit characteristics of soluble solids, flesh firmness and fruit weight and background colour are strong. Fruit from overcropped KORU® Plumac c.v. trees remains brown. 

Suggested target crop loads for young and developing trees are between 8-11 fruit per square centimetre TCA, while well managed, mature trees with a full canopy could target 11-14 fruit per square centimetre TCA.


Clear harvest parameters have been developed to provide a fruit with optimum harvest quality and excellent storage potential. Fruit has been independently tested by Fruition Horticulture since 2005 providing us with positive storage results.

  • No storage disorders have been observed in any trials.
  • The progress of the fruit through 90 and 120 day storage trials have been repeated in a number of years.  
  • The results from maturity parameters and taste test suggest that fruit from Controlled Atmosphere and Smartfresh was ranked higher than fruit from conventional cool storage.
  • Generally KORU® Plumac c.v. is coming out of storage with pressures of around 8.5kg/m². 

Independent scientific testing provided through:

Fruition Horticulture has provided independent scientific testing/monitoring and evaluation of test results for KORU® Plumac c.v. since the first test plantings. We have not been able to find fault in production, storage, market or consumer testing and Fruition Horticulture concluded that 'KORU® Plumac c.v. possesses superior qualities than other commercial varieties' (Dryden & Kerer, 2011).

McGrath AssociationLogos Fruition