Abstract

Carnations, Dianthus caryophyllus, have been cultivated in Chile for several decades as a cut flower crop. At the present time, floriculture occupies 2,124 ha, of which 180 ha are devoted to carnations. Almost all carnations produced are sold in the domestic market. Several diseases affect carnations, among them fairy-ring leaf spot (Cladosporium echinulatum), the most important foliar disease in Chile. Different control alternatives for fairy-ring spot were evaluated on the carnation cv. Sarinah in terms of disease incidence and severity. The study was performed in June-August 2003 with a commercial carnation planting in a greenhouse located in Champa (33o 49Ì€ S, 70o 45Ì€ W) that in previous growing seasons reported a high incidence of fairy-ring leaf spot. The treatments included ammonium bicarbonate (5 g L-1), sodium bicarbonate (5 g L-1), ammonium bicarbonate + mineral oil Srpinguill (5 g L-1 + 10 mL L-1), sodium bicarbonate + mineral oil Srpinguill (5 g L-1 + 10 mL L-1), mineral oil Srpinguill (10 mL L-1), mancozeb (2 g L-1), copper oxichloride (2 g L-1), pentahydrated copper sulfate (1 mL L-1), Trichoderma virens strain Sherwood (Trichonativa) (5 mL L-1) and an untreated control. Based on the results obtained, the most effective treatments were sodium bicarbonate and T. virens. Mancozeb, copper oxichloride, sodium bicarbonate + mineral oil Springuill, ammonium bicarbonate, mineral oil Springuill and pentahydrated copper sulfate were ineffective in controlling carnation fairy-ring leaf spot.