ABSTRACT
Aim: The pathogenic potential of foliar nematode, Aphelenchoides besseyi inducing floral malady symptoms and fluctuation of nematode populations in tuberose were determined under field conditions. Methodology: Pathogenicity of A. besseyi on tuberose cv. Calcutta single was carried out with eight treatments and three replications. The freshly collected A. besseyi was inoculated into tuberose. Observations on plant growth parameters, disease severity and nematode populations were taken and analysed. The population of A. besseyi in tuberose cv. Bidhan Rajani-3 was monitored from the plots of a different set of experiment. Nematode population from flower samples collected from fixed plots at monthly interval during the crop growing period were extracted and estimated. Results: Inoculation of nematodes at higher levels progressively decreased plant growth parameters as compared to uninoculated ones. The inoculated plants displayed typical symptoms of foliar nematode infestation; the outer surface of flower stalk appeared rough, growth stunted, flower stalks distorted, stalk bearing a few florets even failed to bloom. An initial inoculum density of 100 nematodes per plant was found to be pathogenic in tuberose causing significant reduction in yield and quality of flower. Monitoring nematode population during the plant growth period (cv. Bidhan Rajani-3) revealed that A. besseyi maintained maximum population during rainy season coinciding with the start of heavy flush of tuberose and minimum during December to February. Interpretation: An initial inoculum density of 100 A. besseyi per plant was considered pathogenic to tuberose. The nematode population attained peak density during July when the air temperature, relative humidity and total rainfall remained fairly high and lowest during February to December.