Effects of preharvest salicylic acid and oxalic acid treatments on blackberry (cv. Bursa 1) fruit quality

The aim of the current study was to determine how the pre-harvest different dosages of oxalic acid (OA) and salicylic acid (SA) affect the quality of blackberry (cv. Bursa 1) fruits at harvest. Thus, blackberry plants were sprayed with solutions containing 0.5 mM SA, 1 mM SA, 2.5 mM OA, and 5 mM OA seven and fourteen days to before the commercial maturity of fruits. Some characteristics of these fruits were investigated, including their biochemistry (phenolic compounds, organic acids, and general phytochemical characteristics), pomology (fruit width, fruit length, and fruit weight), and physiology (respiration). Regarding the results, the application of SA and OA increased fruit size and fruit weight by up to 40% and 23%, respectively, while leading to a reduction in soluble solid content by up to 7%. However, the organic acids and phenolic compounds with antioxidant impact were unaffected by this decline and were found to increase, especially with OA application. The control group's respiration rate was the highest among the harvested fruits, and the treatments lowered it by 30%. Consequently, the pre-harvest application of oxalic acid or salicylic acid could enhance the quality characteristics of blackberry fruit.