Effect of coffee (Coffea arabica L.) husks extracts in the emergence and growth of cucumber (Cucumis sativus L.)

Abstract

The allelopathy is the effect of inhibiting or stimulating the plant growth, for substances produced by another plant. This study aimed to evaluate the allelopathic potential of the crude extract of the coffee husks on the germination and development of seeds of cucumber (Cucumis sativus L.). The experimental design was in randomized blocks with 10 replicates of 5 concentrations of extracts (0, 5, 10, 15 and 20%) applied in pots containing commercial substrate and 20 seeds of C. sativus in each one. It also tested the allelopathic effect on seeds of C. sativus placed in Petri plates, lined with filter paper and the extracts of 25, 50, 75 and 100% in randomized blocks with 6 replicates for each treatment. The control was carried out with distilled water for both biotests systems. The application of coffee husks extracts on the commercial substrate stimulated the C. sativus biomass development, as the concentration increased. The most concentrated extract, in Petri plates systems, inhibited the development of the radicle in all treatments comparing to the control. Despite of the aqueous extract of coffee husks has shown to be at low concentrations as germination stimulus, when it was applied in high concentrations, inhibition events were observed.