The behaviour of grapevine growers in the decision-making of using Plant Protection Products (PPP) from Palmela region

In current days, the major challenges for farmers are the impact of plant protection products (PPP) on the public health, the environment protection, residues reduction, bees and non-target organisms, as well as, the withdrawal of many active ingredients and climate changes. Given the current situation, sustainable use of PPP is a main objective and priority. The decisions making of using PPP of 235 winegrowers from Palmela region, which do not have regular technical assistance, were assessed during 2016 until 2019. The data analysed included the number of applications, the dosages used and the compliance of pre-harvest interval (PHI). For each year, it was observed that a winegrower, on average, made seven treatments, although the tendency is a decrease to reduce the number of treatments. The PPP most used belong to the groups 3 (Triazoles), M02 (Inorganic) and M04 + 4 (Phthalimides + Phenyl Amides) according FRAC Code. Regardless of the climatic conditions and the disease pressure in the vineyard, the winegrowers used PPP every 14 days. Fear and “empiric experience” sometimes overtake knowledge and technology. That could only be changed with trust between technical assistance and farmers. That could be the solution to face the mentioned challenges and to offer sustainable wines from Palmela region.