DA meter measurements benefit from a protocol to avoid sun-stressed and deeply-shaded portions of the fruit

Spectroscopy techniques show promise for the non-destructive assessment of quality and maturity in tree fruit. However, as with all new technologies, operating parameters must be tested and evaluated to ensure reliability of use. There have been many reports on the appropriate set up and analysis approaches for both visible and near infrared spectroscopy of intact fruits, however, little effort has been placed on the understanding of the fruit physiology and how spatial differences across a fruit might impact the interpretation of resultant data generated from the instrumentation. We have evaluated the use of a DA meter (Sinteleia, Bologna, Italy) for indexing maturity of apples. In early tests it was determined that data collected with the instrument could have extremely large variances. Later work showed that sun exposure of fruit in extreme cases can cause significant losses in chlorophyll and lead to artificially low IAD levels based solely on sub-lethal sunscald as opposed to maturity-related changes. Therefore, IAD was only measured on shaded side of fruits, hoping this approach would more reliably estimate maturity of the fruit.However, further analysis showed that areas of the fruit where no red pigment developed, the fruit IAD values were much lower than surrounding peel having a red pigmentation. In summary, our work showed that when using visible spectroscopy to assess maturity of apples, there must be a protocol established that avoids potentially sun-stressed and deeply-shaded portions of the fruit. With such aprotocol, visible spectroscopy can reliably index apple maturity in the field. SourcesVISIBLE SPECTROSCOPY IAD MEASURES IN APPLE: IMPACT OF STRESS AND SHADING ON MATURITY INDEXINGToivonen, PMA1, Lu, C1, Lannard, B1peter.toivonen@agr.gc.ca1Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, British Columbia, CanadaIHC 2014, International Horticulture Congress, 17-22 August 2014, Brisbane, http://www.ihc2014.org/Picture by http://apal.org.auKey wordsPoscosecha?? ?postcosecha?? ?postharvest?? ?na-oes?? ??? ??? ???????? ????? ??? ?post-r?colte?? ????? ?? ??????????? ??? ?na-oogst?? ?post-raccolta?? ?Obr?bka po?? ?p?s-colheita?? ????????????????? ?hasat sonras??? ??? ?Ernte?? ????????????????? ????? ????????????? ?postcollita?? ?poskliz?ov頠 ????? ??? ??? ??? ?nakon branja?? ?pozberov頠 ??? ?obdelovanje zemlje po?? ?post-colleita?? ?????? ??????? ?pascapanen?? ??il?onn postharvest?? ??????? ?p?c ra?as?? ?derliaus apdirbimas po?? ?lepas tuai?? ??? ?? ???????? ?post-recoltare?? ??????? ??????? ???????????????????? ?????????????? ?????????????????? ?sau thu ho?ch?? ?????????????????? ?zangemva kwenkathi yokuvuna?? ??? ?Manzana?? ??? ?apple?? ??? ???????? ????? ??? ?pomme?? ??????? ?????? ?appel?? ?mela?? ?jab?ko?? ?ma?㠠 ????????? ?elma?? ??????? ?Apfel?? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ????