S16 - Session O3 - Protected cropping of sweet cherry: Microclimate and fruit quality

Authors: Cameron Stone *, Dugald Close, Sally Bound

Protected cropping systems (PCS) are increasingly being deployed over cherry orchards due to fruit cracking induced by late season rainfall events. The objective of this study was to investigate, in relation to slope and proximity to the edge of a continuous (21 ha) vented PCS, microclimates and effects on fruit quality. 'Staccato' on 'Colt' rootstock trained as a Spanish Bush was studied during the 2020-21 season. Climate data was recorded throughout the growing season between the 17 th ofOctober 2020 and the 31 st of March 2021 at 30-minute intervals at four sites. Sites 1&2 were105 m and 75 m from the nearest edge and 125 m and 114 m above sea level (asl), respectively, while sites 3&4 were 60 and 50 m from the nearest edge at elevations of 111 m and 102 m asl, respectively. Average daily temperatures were 0.5 °C warmer further from the PCS edge at higher elevations (sites 1 and 2), while average minimum relative humidity was similar across all locations. Fruit compression firmness (343.4 g/mm), dry matter content (DMC) (19.2%) and total soluble solids content (TSS; 18.5 °Brix) was significantly higher at site 1, furthest from the PCS edge at the highest elevation in contrast to fruit harvested at site 4, the lowest location in closest proximity to the PCS edge where compression firmness, DMC and TSS were 251.1 g/mm, 16.2% and 15.5 °Brix, respectively. Crop loads were similar at each of these two sites; therefore, it is speculated that elevated fruit compression firmness was due to relatively high DMC and Brix driven by warmer temperatures in a PCS where venting maintained uniform relative humidity across all sites. The findings of this study will inform grower management and harvest practices under vented PCS.