Relationship between size and weight

  • Depending on the density of the apple (and this will vary within as well as between varieties) size/weight relationships can vary markedly.
  • This can cause considerable problems with accurate size and targeted weights in final packs.
  • There are always ‘difficult sizes’ within any range of sizes. For example, where the standard size has been 65-70 mm in Cox, a reduction in size range to 63-68 mm will often make achieving the target weight impractical where fruit density varies on a regional basis.
  • The lower density of Discovery will dictate lower pack ‘target weights’ than, for example Cox.
  • This will impact on increased haulage charges per lb/kg of fruit.
  • Delivering accurate size and consistent pack weights will depend on optimising performance where a weight grader is used.
  • Optical cameras for sizing will improve sizing accuracy, but fruit density will still influence pack weights particularly where packs are by ‘count’ but a minimum pack weight is still required.