At Cesens, we have just implemented a new predictive model designed to control brown spot caused by Alternaria alternata in mandarin orange crops.
According to data from the Ministry of Agriculture, Spain is the leading producer of citrus fruits in Europe and exports 48% of its production to international markets; it is also the world’s largest exporter of citrus fruits for fresh consumption, accounting for 40% of global volume. Mandarin varieties account for nearly 40% of the total area devoted to citrus cultivation in Spain.
Brown spot of mandarin oranges is characterized by the appearance of necrotic lesions on shoots, leaves, and immature fruit, causing tissue necrosis and leading to the premature abscission of both affected leaves and fruit.
Based on this premise, we have incorporated a generic infection model (GIM) described by Magarey et al. (2005), which estimates the duration of leaf wetness required to reach a specific disease incidence/severity threshold at a given temperature.
To make the results easy and intuitive to interpret, we have converted the model’s output into a percentage and included a graph that allows us to quickly see how the risk of a brown spot infection is evolving in our mandarin orchards.
This model joins the list of predictive models already available to Cesens, which is extremely helpful in determining the critical period of infection and scheduling fungicide treatments more efficiently.
