## 4 Discussion
For this reason, new products and techniques that can be used in this production method and that can increase efficiency and quality are being developed. It is of great importance for human health to determine the content of heavy metals [54], which are scientifically proven to cause great harm to human health, in strawberry fruit, as strawberry production and consumption amounts are increasing around the world. This study was carried out to determine the effects of organic and conventional farming methods on heavy metal (Pb, Cu, Zn and Cd) content in strawberry fruit. Zn is a trace element necessary for a healthy person. However, high-dose Zn intake exceeding the daily dose tolerable by the human body (0.43 mg/kg body weight; [55]) can damage the pancreas, impair protein metabolism, cause arteriosclerosis and have a toxic effect after exceeding certain amounts in living things [56]. [PERSON] et al. [26] evaluated the heavy metal content of strawberries grown in conventional and organic farming areas in the east-central region of Tunisia and reported higher heavy metal content in strawberry fruits in conventional farming compared to organic farming. Similar to our study findings, [PERSON] et al. [26] reported lower Zn (0.98 mg kg\({}^{-1}\)) content in strawberry fruits in organic agriculture compared to strawberry fruits in conventional agriculture (1.29 mg kg\({}^{-1}\)). On the other hand, [PERSON] et al. [57] reported that raspberry fruits obtained from organic farming had significantly more (\(p\leq 0.05\)) cadmium, zinc, manganese and vanadium than those obtained from conventional cultivation, unlike the findings we obtained. It is thought that this situation may be caused by climatic and soil factors. The presence of heavy metals in a plant depends on factors such as the type of plant and its total and accessible content in the soil. [PERSON] et al. [58], in their study evaluating the effects on fruit quality of two different garden strawberries grown in technologically polluted soils, reported that the highest Zn content in strawberry fruit was 3.78 mg kg\({}^{-1}\). [PERSON] et al. [28] evaluated the quality of strawberry fruit and heavy metal contents in the Lublin region and reported the highest Zn content of 1307 mg kg\({}^{-1}\). While one of the strawberry fruit zinc content values in these two reference studies is close to our study findings obtained from conventional agriculture, the other is a higher value; the values in both studies are higher than our study findings obtained from organic agriculture. Contrary to our study findings, in the literature review of Cakmakci and Cakmakci [43], in which product quality characteristics in organic and conventional agriculture were examined, Zn content was higher in organically grown strawberry fruits than in conventional ones. Cu is the basic building block for hair, skin, bones and some internal organs [59]. However, high Cu intake causes the slowing of growth and development, the graying hair, decreases in body temperature and brain damage [59]. According to the EFSA Scientific Committee, the acceptable Cu intake for an adult human per day is 0.007 mg kg\({}^{-1}\) body weight [60]. [PERSON] et al. [58] evaluated two different strawberry cultivars (_Fragaria x ananassa_) grown in technologically contaminated soils and reported the highest Cu content as 2.83 mg kg\({}^{-1}\). [PERSON] et al. [28] reported this value as 0.424 mg kg\({}^{-1}\) in their study in the Lublin region. The average Cu values we found in this study are in the range of the values obtained from the aforementioned studies. In the literature review of Cakmakci and Cakmakci [43], in which product quality characteristics in organic and conventional agriculture were examined, Cu content was higher in organically grown strawberry fruits than in conventional ones. While these results are similar to our study findings obtained in the spring season, they are the opposite for the autumn season.