Nematology Department, Orissa University of Agriculture and Technology, Bhubaneswar-751 003.
Among nineteen selected crop plants, tested as possible hosts of Macroposthonia ornata only rice was found to be excellent host; while cabbage, cauliflower, corn, okra, cow pea, sorghum, bajra, mustard and ragi were good hosts; brinjal, garden pea, chilli, blackgram, green gram, soybean and tomato were fair hosts; and cucumber and niger were considered to be the poor hosts.
Pathogenic relationship of this ring nematode species with ragi plant was established by releasing nematodes in logarithmic series (0 to 10,000 per pot) around the root zones of one month old ragi plants (Var. T-20) growing in autoclaved soil. After 3 months, the nematodes were found to reduce shoot height from 1.45 to 46.32%, root length from 6.08 to 61.78%; and loss in shoot dry weight averaged from 3.33 to 69.06% and root dry weight from 9.09 to 48.05% corresponding to different levels of inoculum.
