Effectiveness of biological and chemical fungicides for diseases control in barley (Hordeum vulgare)

Background/Objective. In the cultivation of barley in Mexico, diseases cause economic losses; chemical control has been the most effective way to mitigate their effects; however, it is necessary to explore other environmentally friendly control strategies. The objective was to compare, under field conditions, the effectiveness of biological and chemical fungicides for the control of pathogens that cause the main barley diseases. Materials and Methods. In spring-summer 2022, five experiments were conducted in different environments. The design was randomized complete blocks with three repetitions. Esmeralda was the variety used. Two biological fungicides (SERENADE® OPTI and Trichoderma Sub) were evaluated; and one, chemical (Azimut® 320 SC). They were applied three times. The diseases occurred naturally. The variables measured were: days to heading (DH), days to physiological maturity (DPM), plant height (PH), grain yield (YIELD), final disease severity: foliar (FFOLS), yellow rust (FYRS), leaf rust (FLRS). Results. The analysis of variance showed significant variation for YIELD, FYRS and FLRS (p≤0.01). In YIELD, the best biological fungicide was SERENADE® OPTI with a yield of 3,555 kg ha-1, compared to the control (3,086 kg ha-1). For FYRS and FLRS the most effective was Azimut® 320 SC, followed by Trichoderma Sub. Conclusion. The efficacy of the chemical for foliar diseases was 38 %, yellow rust 91 %, and leaf rust 100 %. Chemical control continues to be the most effective for controlling pathogens that cause barley diseases.