Early blight, caused by Alternaria solani, is one of the most important diseases of tomato in Brazil. New alternatives to fungicides with low environmental impact and low toxicity to living beings have been tested to evaluate their ability to control diseases. Turmeric, Curcuma longa, has compounds in its rhizomes with proven antimicrobial activity. Therefore, the objective of this study was to evaluate the potential of turmeric extracts and curcumin on the control of tomato early blight under greenhouse conditions. The treatments were: 1 and 10% turmeric extracts, 50 and 100 mg/L curcumin solutions, acibenzolar-S-metil (ASM) (25 mg a.i./L), copper oxychloride (1,100 mg a.i./L), azoxystrobin (80 mg a.i./L) and control (water). The disease control showed by turmeric extracts and curcumin solutions was similar to cupric fungicide, but inferior to azoxystrobin control. There was no statistical difference in commercial fruit production between treatments. Only 50 mg/L curcumin treatment had a higher percentage of bigger fruits compared to the control. These results show the potential of turmeric and curcumin for the control of tomato early blight.
turmeric; plant extracts; tomato early blight; alternative plant disease control
