Cultivar and phenological stage susceptibility of almond flowers to
Monilinia laxa
infection
Erick Zúñiga, Rosario Torres, Lidia Aparicio‐Duran, Laura Torguet, Xavier Miarnau, Neus Teixidó, Carla Casals Abstract
BACKGROUND
Blossom blight caused by Monilinia laxa is a major constraint to almond production in southern Europe, yet variation in floral susceptibility among cultivars and phenological stages remains poorly understood.
RESULTS
Floral susceptibility to M. laxa was assessed through 6 years of field surveys across 21 almond cultivars, artificial inoculations of detached flowers from 15 cultivars at BBCH 60/Felipe F1 over two consecutive years, and inoculations of three cultivars at four phenological stages from BBCH 58/Felipe D to BBCH 65/Felipe F2. Consistent cultivar‐dependent patterns were identified: ‘Mardia’, ‘Penta’, ‘Vairo’, ‘Tardona’, ‘Marinada’, ‘Constantí’, and ‘Lauranne’ showed low incidence, whereas ‘Soleta’, ‘Marta’, ‘Guara’, ‘Tuono’, ‘Marcona’, ‘Francolí’, and ‘Tarraco’ were among the most affected. Artificial inoculations confirmed marked cultivar differences, with incidence ranging from 0–11% in ‘Marcona’ to 28–78% in ‘Soleta’ and 36–81% in ‘Tardona’. Susceptibility across floral phenological stages followed a similar pattern in the three cultivars assessed, although with different infection intensities. Using ‘Soleta’ as an example, infection was highest at pre‐anthesis BBCH 58/Felipe D (88.9%) and early anthesis BBCH 60/Felipe F1 (80.6%) and declined by late anthesis BBCH 65/Felipe F2 (55.6%).
CONCLUSION
Almond flower susceptibility to M. laxa is strongly cultivar‐ and phenology‐dependent. These findings refine the epidemiological framework of almond blossom blight by identifying cultivar‐specific risk and critical windows of floral susceptibility. Incorporating cultivar risk and early floral susceptibility into disease‐warning systems could improve fungicide timing and support more precise integrated management of almond blossom blight. © 2026 Society of Chemical Industry.