Disease status and combined effect of biological control and organic amendments in managing stem rot disease of carnation caused by Rhizoctonia solani

Abstract

The present study was carried out to know the effect of different soil amendments and biological control on disease incidence, different plant growth and flower parameters. Incidence of stem rot was found serious in almost all the locations surveyed, maximum incidence being recorded at Berthin (33.7%) in district Bilaspur followed by Rajgarh (32.0%), Solan (27.3%) and Matnali (27.1%) in district Sirmour in contrast to lowest incidence (11.2%) of stem rot in Shimla. Integration of Melia azedarach seed (powder) along with Trichoderma viride as well as Neem cake with T. viride and T. harzianum gave maximum reduction (75.67%) in disease incidence of stem rot with minimum disease incidence (6%), in comparison to 24.67 per cent in control followed by Bacillus subtilis + Melia azedarach (8%). These treatment also improved the plant growth and flower quality parameters by giving the average plant height to 82.32 cm, 81.05 cm, stem length (76.64 cm, 75.91 cm), number of flowers per plant (3.79, 3.68), flower size (7.20 cm, 7.17 cm) and took less number of days to first flowering. Disease management practice alone is not sufficient until integrated with other components, as disease is a complex phenomenon governed by many factors. The integration of effective management practices such as plant oils, botanicals and antagonists would be important for the successful management of plant diseases, thus showing its practical applicability in field in mitigating the losses caused by disease in carnation.