Early season detection and mapping of Pseudomonas syringae pv. actinidae infected kiwifruit (Actinidia sp.) orchards

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is an emerging disease of kiwifruit (Actinidia sp.). It has the potential to cause considerable production losses; therefore the ability to monitor and map the disease is important for industry-wide disease management. Using industry-collected infection data and an archived time-series of high-resolution satellite imagery, Psa disease monitoring in kiwifruit orchards was attempted for the 2010–11 growing season in the Bay of Plenty, New Zealand. Multiple vegetation indices were generated from imagery and a binomial logistic regression used to relate these vegetation indices to the Psa disease response. Results showed that the early season (2 October) photosynthetic vigour ratio was the most effective for differentiating infected and non-infected orchards. Omission and commission errors were observed, but were in part due to issues with data quality. The results were encouraging for the potential timely use of satellite imagery for monitoring and mapping Psa infections in kiwifruit.