Application of Bordeaux mixture for Botrytis control in passion fruit (Passiflora ligularis Juss) cultivated under organic farming in the Andean region

Abstract

[EN] The aim of this research was the determination of the best conditions for applying Bordeaux mixture for the control of gray mold or rot (Botrytis cinerea) in passion fruit (Passiflora ligularis Juss) grown in organic farming in the Andes. This disease is responsible for nearly 30% loss of production in the province of Tungurahua (Ecuador). To do this, three doses and four frequencies of application in two locations were evaluated. The locations were in the sectors El Galpón and Runtun which are cantons of Patate and Baños, respectively, in Ecuador. Therefore, each experimental unit was composed of 12 blocks (3 doses x 4 frequencies) together a control test with three plants each. In total, 78 plants were evaluated. The doses used were 5 g CuSO4/litre of water (D1), 10 g CuSO4/litre of water (D2), and 15 g CuSO4/litre of water (D3). The studied application frequencies were every 7 days (F1), every 14 days (F2), every 21 days (F3) and every 28 days (F4). From the first application of the treatment, the efficacy was evaluated every 15 days up to 90 days, also performing an economic analysis of the treatments. The evaluation of the effectiveness of each treatment was performed using an affection index, defined as the ratio number of affected organs (branches, leaves, flowers or fruits) and the number of total organs. It has been demonstrated that treatment with 0.5 kg of CuSO4 in 100 litres of water applied every 21 days gives good results for the control of gray mold. Complete removal of the Botrytis was achieved at 75 days after starting treatment. Treatments with higher dose level and the same frequency of application did not improve the results.