Suppression of Botrytis cinerea sporulation by Clonostachys rosea on rose debris: a valuable component in Botrytis blight management in commercial greenhouses

• Published in: Biological control 2003-03, Vol.26 (3), p.311-317
• Main Authors: Morandi, Marcelo A.B, Maffia, Luiz A, Mizubuti, Eduardo S.G, Alfenas, Acelino C, Barbosa, José G
• Format: Article
• Language: English
• Subjects: Biological control; Botrytis cinerea; Clonostachys rosea; Crop residues; Necrotrophic pathogens; Rosa hybrida
• ISSN: 1049-9644; 1090-2112
• DOI: 10.1016/S1049-9644(02)00134-2

Botrytis blight, caused by Botrytis cinerea (Bc), is an important disease on roses grown in plastic greenhouses in Brazil. Biocontrol with Clonostachys rosea (Cr) applied to leaves and crop debris to reduce pathogen sporulation can complement other control measures for disease management. Two experiments, each with a rose cultivar, were conducted in a plastic greenhouse. For ‘Red Success,’ four treatments were compared: (1) control; (2) fortnightly sprays of Cr; (3) weekly sprays of mancozeb; and (4) weekly sprays of either Cr or mancozeb to the lower third of the plants and the debris. For ‘Sonia,’ treatment 4 was not included. Samples were taken from debris (leaves and petals) at ten 15-day intervals and plated on PCA medium. Sporulation of fungi and incidence of Botrytis blight on buds were assessed. For both cultivars, C treatments significantly ( P=0.05) reduced Bc sporulation. However, disease incidence was not consistently reduced, probably because the applications of C. rosea started when Botrytis blight epidemic was advanced and no sanitation practices were performed on nontreated plots. From the present and previous studies, continuous application of Cr on debris, associated with sanitation practices, has the potential to reduce Bc sporulation and disease incidence in the buds.