Evaluation of Fungicides and Application Strategies for the Management of the Red Leaf Blotch Disease of Almond

Red leaf blotch (RLB) of almond, caused by Polystigma amygdalinum, is an important foliar disease this nut tree in the Mediterranean basin and especially Spain. In recent years, control has become a key factor management Spanish almond orchards. The RLB not easy due to intrinsic factors (e.g., long infection latency periods) low number registered fungicides country. From 2015 2019, different field trials were conducted Lleida region, NE Spain, evaluate efficacy several fungicide products application strategies disease. Systemic fungicides, which included fluopyram, trifloxystrobin, mixtures fluopyram + trifloxystrobin pyraclostrobin boscalid, performed better than contact penetrant showed up 90% against RLB. However, tested varied depending on year. terms strategies, when applications following specific meteorological conditions (after 15 days from >15 mm rainfalls with ?10–15 °C as minimum average temperature), their was comparable that calendar-based treatments (every 14, 21, or 31 petal fall) but fewer (depending year, 2–4 compared 5–9 for calendar treatments).