Effect of Acetylsalicylic Acid in Mitigating Biotic Stress in Grass (Panicum maximum)

Climate change and increasing biotic stressors pose a significant threat to the productivity and quality of tropical forage systems. This study evaluated the effect of foliar application of acetylsalicylic acid (ASA) on agronomic and nutritional parameters of Panicum maximum grown under tropical conditions in Orellana province, Ecuador. A randomised complete block design was employed with four treatments: Control (0 L/ha-1), T1 (0.5 L/ha-1), T2 (1.0 L/ha-1), and T3 (1.5 L/ha-1) of ASA, applied every 35 days over an 8-month period. Plant height, herbage mass, and tiller density were measured periodically, and forage samples were collected for bromatological analysis. ASA application significantly enhanced plant performance. The highest dose (T3) increased plant height by 13%, herbage mass by 56% (5751 vs. 2534 kg/ha), and tiller density by 22% compared to the control (P < 0.05); Regarding nutritional quality, crude protein content improved from 10.0% in the control to 13.0% in T3. Organic matter content also increased in treated plots, while ash content showed a slight reduction. However, structural fiber fractions remained high across all treatments (neutral detergent fiber [NDF] > 70%; acid detergent fiber [ADF] > 40%), which may restrict voluntary intake and digestibility in ruminants. Despite this limitation, the improved protein content and biomass yield suggest that ASA foliar application can enhance forage value in tropical environments. These findings support ASA as a cost-effective and eco-friendly strategy for mitigating biotic stress and promoting sustainable forage production in dairy systems. Further research is recommended to assess the consistency and duration of these effects under varying environmental and management conditions. Keywords: Acetylsalicylic acid, biotic stress, Panicum maximum, forage quality, forage yield, sustainable livestock systems