Santosh KumarAnisha, P.N.2016-10-012016-10-012013-12http://krishikosh.egranth.ac.in/handle/1/79685Thesis-PhDThe present investigation was carried out at the Model Floriculture Centre, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, during 2011-12 and 2012-13 to study the impact of herbal extracts on the microbial vascular plugging, quality and longevity of cut roses Konfetti and Bordeaux. The major cause of vase life reduction in cut flowers is water relation interruption which is mostly due to vase solution microbial proliferation and consequently vascular occlusion resulting in solution uptake reduction. The microbial vascular plugging of cut roses Konfetti and Bordeaux was confirmed through the findings from SEM. A broad range of chemical biocides has been suggested to prevent the proliferation of microorganisms in vase solutions. In order to replace chemicals with natural compounds as antimicrobial preservatives used in solutions for cut flowers five herbal extracts namely, Curcuma longa, Azadirachta indica, Piper betle, Ocimum sanctum and Allium sativum were assessed for their antimicrobial properties against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Mucor sp. and Rhizopus sp. isolated from vase solution of cut roses. Among these betel leaf had the highest zone of inhibition against all these microorganisms and its MIC was found to be 2%. Further, in order to compare the in-vivo efficacy of betel leaf extract with 8-HQC as well as to assess the effect of betel leaf extract on quality and longevity of both the cultivars of rose in holding and pulsing solutions, experiments were laid out in Factorial CRD. 2% sucrose + 2% betel leaf extract and 6% sucrose + 2% betel leaf extract were respectively the best among the holding and pulsing solutions. They improved the vase life, water relations, fresh weight, flower diameter and chlorophyll content compared to 8-HQC. Among the cultivars Bordeaux showed better response in improvement of quality and longevity. Thus it is evident from this study that betel leaf extract can be used as an organic biocide in the vase solutions for the improvement of quality and longevity of cut roses.enplant extracts, microbiology, floriculture, cut flowers, vase life, vascular system, microbial physiology, quality controls, longevity, rosesThesis