Evaluation of proposed integrated diseases management strategies in blackberry cultivation according to its sustainability

Abstract

The production of blackberry in Colombia is a source of income and rural employment in 18 departments; however, the plant is affected by diseases such as gray mold, anthracnose and powdery mildew that can cause losses of up to 70%. The control of these diseases is mainly carried out with chemical fungicides such as benomyl, carbendazim and mancozeb applied every 7 or 15 days. Nevertheless, being a continuous fructification plant of weekly harvest, the proximity between the application of the pesticides, the harvest, and its consumption represents a health risk due to the residually of these molecules, condition that affects its innocuousness and sustainability. Accordingly, this work aimed to develop an integrated management strategy for these diseases. Two strategies were proposed integrating agricultural labors with applications of Tricotec®-Kendal® or Tricotec®-EcoSwing®, and three fungicides applied according to the incidence of each disease, compared with the diseases producer management. In 77 evaluation days the effectiveness of the strategies was assessed according diseases incidence reduction, on fruit production, environmental impact, using the environmental impact quotient in the field (EIQf), and the reduction of fruit pesticides residues. According to the results obtained, the strategy Tricotec®-Kendal® with applications of a fungicide based on azoxystrobin + difeconazole showed the lowest diseases incidence, averaging 3% for gray mold, 11% for anthracnose, and 21% for powdery mildew and the highest amount of fruit harvested averaging 5,668 g. The strategy showed the lowest EIQf (5.3) compared with a value of 81.50 obtained with the traditional producer management, as well as the least amount of pesticides residues, corresponding to azoxystrobin (0.10 mg/kg) and difeconazole (0.046 mg/kg); these, however, remained within the maximum residue limits for pesticides stated by the European Union for blackberry.