Control of early blight and effect on growth variables of tomato plants by using homeopathic drugs

Homeopathy can be an alternative to control plant diseases by means of the activation of resistance genes. The aim of this study was to evaluate the action of the homeopathic drugs Propolis, Sulphur and Ferrum sulphuricum at the dynamizations 6, 12, 30 and 60CH (centesimal hahnemanian dilutions) on the control of Alternaria solani and on growth variables. Hydroalcoholic solution at 10% and distilled water were the control treatments. At 19 days after transplanting, the 6th leaf of each plant was treated and, at 72 hours after the treatment, the 6th and the 7th leaves were inoculated with A. solani. The disease severity was assessed and the area under the disease progress curve (AUDPC) was calculated. The volume and the dry mass of roots were evaluated, as well as the fresh and the dry mass of shoots. Sulphur at 12 and 30CH, Ferrum sulphuricum at 6, 12 and 30CH and Propolis at all dilutions reduced the AUDPC by 17% to 49%. Sulphur at 60CH and hydroalcoholic solution at 10% had a systemic effect on resistance induction. Propolis at 30 and 60CH increased the volume of roots by 39% and 33%, respectively, the fresh mass of shoots by 35% (30CH) and the dry mass of roots by 38% (30CH). Sulphur at all dilutions increased the mass of shoots by 23% to 37%, while at 60CH it increased by 59% the mass of roots, which also occurred for Ferrum sulphuricum at 60CH (65% increment). These results indicate that homeopathic drugs can control early blight and increase the growth of tomato plants.

Homeopathy; Alternaria solani; resistance induction; metabolic cost