Effect of canopy position on apricot fruit quality

1. How to use this poster template… • Simply highlight this text and replace it by typing in your own text, or copy and paste your text from a MS Word document or a PowerPoint slide presentation. • The sub-title text boxes can be moved up or down depending on how big or small your ‘Introduction’, ‘Aim’, ‘Method’, ‘Results’ and ‘Conclusion’ are. • The body text / font size is up to you but should be between 8 and 16 points. Arial, Helvetica or equivalent. • Keep body text left-aligned, do not justify text. • The colour of the text, title and poster background can be changed to the colour of your choice, but white on black is the most successful on large screens and darker rooms. • The layout is only a guide. You may choose to add more or less image/text boxes and move them about as required. Creativity is encouraged. Effect of canopy position on apricot fruit quality Jill Stanley, Ross Marshall, Claire Scofield The New Zealand Institute for Plant & Food Research Ltd, Clyde, New Zealand

2. Introduction & Objective • Apricots delivered to consumers show a huge amount of variation in quality, ranging from those that are unripe and have little flavour through to those that are over-soft (Bruhn et al., 1991). Some of this variation may be due to different fruit quality among positions within trees. • Apricots have been reported to be larger and have higher soluble solids concentration (SSC) in canopy positions exposed to more light (Lichou et al., 1999), but no data were presented to support this conclusion. • There is little known about the effect of canopy position on postharvest storage of apricots • The aim of this trial was to identify the effect of canopy position on apricot fruit quality.

3. Materials and Methods • Monitored three blocks of ‘CluthaGold’ apricot trees: • One centre-leader & two multi-leader (vase) • Collected fruit from 8 different positions within trees at 3 harvest times and measured fruit weight and soluble solids concentration • Also collected two fruit from each position that were at commercial maturity, stored for 3 weeks at 0oC then held at 20oC for 4 days. Mealiness was assessed by 3 trained panellists. • The proportion of light interception reaching each canopy position was recorded by taking instantaneous measurements of photosynthetically active radiation (PAR) within the canopy and simultaneously measuring PAR above the canopy.

4. Results Fig. 1. Relationship between light transmission and fresh weight (A) or soluble solids content (B) in three ‘CluthaGold’ apricot orchards. A B Soluble solids concentration (%) Fresh weight (g) Light transmission (% ambient photosynthetically active radiation) • Light transmission into apricot canopies was lowest (1 to 23%) in the lower inner canopy positions, particularly for the multi-leader trees (data not presented) • There were significant relationships between light transmission and fruit fresh weight (Fig. 1A) and between light transmission and fruit soluble solids concentration (Fig. 1B).

5. Results • When fruit were firm after cold storage and shelf-life, there was no difference in mealiness between canopy positions (Fig. 2A) or between canopy types (Fig. 2B) • If fruit were soft, those from the upper canopy were mealier than those from the lower canopy (P=0.01) (Fig. 2A) and those from centre-leader trees were mealier than those from multi-leader trees (P=0.001) (Fig. 2B) • These results differ from peach. Peach fruit from the upper canopy exhibited longer shelf-life capacity than from lower light canopy positions because of reduced mealiness and internal browning (Cristosto et al., 1997) • Fig. 2. Relationship between flesh firmness and mealinessscore (from 0 (not mealy) to 3 (very mealy)) of ‘CluthaGold’ apricots collected from 3 harvests and assessed after 3 weeks at 0oC and 4 days at 20oC ,harvested from A) upper or lower canopy positions and B) centre-leader or multi-leader trees. Height P=0.002 FF P<0.001 H x FF P=0.01 Very mealy System P<0.001 FF P<0.001 H x FF P=0.001 Not mealy

6. Conclusions • Fruit in higher light positions of the canopy were larger and had higher soluble solids concentrations • Post-storage mealiness increased when fruit were softer and were from higher light positions or from centre-leader trees • Short-termmanagementsolutions to improve apricot fruit quality include: • Increase light penetration into the lower canopy positions by more intensive pruning and/or by the use of reflective material on the ground • Selective thinning to retain more fruit in high light positions and reduce numbers of fruit in lower light positions • Manage harvest and storage protocols to ensure fruit do not become too soft when reaching the consumer • Longer-term solutions include: • Redesigning orchard systems using different rootstocks and training systems to maximise light penetration into the tree canopy • Breeding new cultivars that have larger fruit that have higher soluble solids concentrations at commercial harvest, and have good storage capability.

7. Selected references Bruhn CM, Feldman N, Garlitz C, Harwood J, Ivans E, Marshall M, Riley A, Thurber D, Williamson E 1991. Consumer perceptions of quality - apricots, cantaloupes, peaches, pears, strawberries, and tomatoes. J. Food Quality 14:187-195. Crisosto CH, Johnson RS, DeJong T, Day KR 1997. Orchard factors affecting postharvest stone fruit quality. HortScience 32(5):820-823. Bruhn CM, Feldman N, Garlitz C, Harwood J, Ivans E, Marshall M, Riley A, Thurber D, Williamson E 1991. Consumer perceptions of quality - apricots, cantaloupes, peaches, pears, strawberries, and tomatoes. Journal of Food Quality 14(3): 187-195. Acknowledgements This research was funded by the New Zealand Ministry of Business, Innovation and Employment (Contract number C06X0806). Thanks to Peter Alspach for statistical advice. Thanks to H & J Roberts, Summerfruit Orchards Ltd and J Taylors for supplying the fruit.