Investigation of the effect of ferulic acid against Lasiodiplodia theobromae causing gummosis, trunk and branch canker on nectarine

The Prunus genus includes economically important tree species such as almond, apricot, cherry, plum, and nectarine/peach. Nectarine production has increased significantly in Türkiye and this country ranks second in global nectarine exports. However, climate change and fungal pathogens cause diseases such as gummosis, trunk and branch canker in nectarine trees, leading to yield losses and even tree deaths. This situation highlights the need to develop sustainable solutions. This research, conducted for the first time in the world and Türkiye, aims to develop an environmentally friendly method without the use of chemicals against Lasiodiplodia theobromae, which causes gummosis, trunk, and branch canker in nectarine trees. The 'Bigtop' nectarine variety and L. theobromae isolate obtained from Yozgat were used in this study. Infection was controlled by applying ferulic acid concentrations of 1, 20, 50, and 100 ppm to seedlings through the soil. The application of ferulic acid minimized the adverse effects of L. theobromae infection on the plants. While the infection impaired plant growth, ferulic acid reduced cell membrane damage and prevented the accumulation of reactive oxygen species. 100 ppm ferulic acid reduced the effects of stem canker by lowering malondialdehyde accumulation to the lowest level. Additionally, ferulic acid strengthened the cell wall by contributing to the synthesis of lignin and pectin, thereby providing a barrier against pathogens. The application supported plant growth by increasing xylem diameter and enhanced photosynthesis. The results indicate that ferulic acid supports morphological development in nectarines and triggers the defense mechanism.