Research on the use of copper in vegetable production

The use of copper in agriculture dates back to ancient times, initially as inorganic compounds used as fungicides to control downy mildew and seed borne pathogens (seed disinfection). By the mid-20th century, copper began to be utilized in the production of vegetables and fruits to manage bacterial diseases. While copper compounds serve as effective preventive fungicides, their excessive application can lead to detrimental effects, such as copper accumulation in the soil, which negatively impacts soil microorganisms, induces plant stress, and diminishes soil fertility. This study focused on agricultural farms involved in field and vegetable production, aiming to identify the most commonly used copper compounds and their application rates per unit area. The research surveyed 37 farms in Vojvodina Province, northern part of Serbia, where the average area dedicated to vegetable cultivation ranged from 1.2 to 28.6 hectares. The main vegetables cultivated were: peppers (52 ha), cabbage (47 ha), beans (32.5 ha), onions (21.8 ha), eggplants (12.3 ha), tomatoes (14.3 ha), brussels sprouts (11.5 ha), watermelons (10.8 ha), and melons (7.1 ha). Additionally, pumpkins, beetroot, and swiss chard were grown on areas of less than 5 ha each. The highest frequency of copper compound applications was observed in the cultivation of peppers, cabbage, and beans in the control of bacterial and fungal diseases. The most commonly used copper products were: hydroxide (71.5%), oxychloride (10.3%), oxide (8.2%), sulfate (6.8%), and tribasic sulfate (3.2%). The amount of pure copper applied per unit area ranged from 0.85 to 6.23 kg annually.