Control of Botrytis cinerea Pers. in chrysanthemum (Chrysanthemum × morifolium) with wild vine extracts

In Mexico, the floriculture industry has grown over the last decade in terms of land area and new species has been cultivated with an intensive management. However, Botrytis cinerea has been affecting a wide range of floricultural products causing losses in production. Its strains cause necrosis in flowers, leaves and buds. A possible alternative control is the use of wild vine leaves extract (Vitis spp.) (WVLE). The objective of this work was to evaluate the effectiveness of concentrations of wild vines leaves at 100, 80, 40 and 0% (control) and the chemical control in chrysanthemum cultivar ‘Spider’. Four replicates per treatment were established in a completely randomized block design. When flower buds appeared, the plants were sprayed with the different extract treatments and 24 h later, they were inoculated with B. cinerea spores at a concentration of 2.5×10⁶ conidia mL^‑1. Severity and progress of the disease were evaluated at 0, 4, 7, 11, 14, 18 and 21 days after inoculation (DAI). The results indicated that the highest severity occurred in the control at 21 DAI reaching values of 80 to 100% of damage, followed by treatments with 80 and 40% WVLE. The result of 100% WVLE was close to the chemical control, expressing a lower severity with respect to the 0% WVLE as well as a lower development curve of the disease.