Diseases due to mycoplasma-like organisms (MLOs) in floriculture—an ecological perspective

Sriram Nursery is one of the largest horticultural nurseries in Mansarovar, Jaipur, India. It is devoted to floriculture largely of Chrysanthemums, Asters and Marigolds which are known for sporadic occurrence of diseases due to MLO, with characteristic vegetative as well as floral symptoms. An ecological evaluation of such diseases is presented here considering their incidence in large areas as disease pathosystems. A disease pyramid is defined where each of the five components corresponding to five sides of the pyramid is necessary for the incidence of disease. Some cultural practices, such as rooting of cuttings, and use of suckers, are presumed to increase chances of disease incidence. Further, woody ornaments may act as refuges as well as sources of ‘vectors’ for the disease.