Basket grass (Oplismenus compositus) as a new host for tea root lesion nematode, Pratylenchus loosi

Tea root lesion nematode (Pratylenchus loosi Loof, 1960) is the most important damaging agent in tea gardens in the north of Iran. Many parts of tea plantations are infested by this nematode. Tea plant is the main host for this nematode and it has only been reported on the tea plant in Iran, however, other plants such as citrus, apple, pear, quince, grass and several weeds were reported as hosts for this nematode in other parts in the world. Having much spread and compatibility with tea bushes, weeds are very important in tea plantations. Almost 95 species of weeds have been reported in tea gardens until now. Among them Poaceae and Astraceae have much frequency. In this research 13 species of weeds which have the most abundance in tea gardens i.e. Oplismenus compositus, Convolvulus sepium, C. arvensis, Potentilla reptans, Anagalis arvensis, Erigeron Canadensis, Paspalum dilatatum, P. disticum, Cyperus esculentus, Acalypha austrialis, Rubus fruticosas, Poa annua, Setaria viritis were examined from the viewpoint of being host for the tea root lesion nematode. Among examined weeds natural infectious to P. loosi was observed in basket grass (Oplismenus compositus) roots. The infested area was in Amalash region located at 50°06'26" N, 37°03'28" E and 132 m a.s.l. Final identification of the nematode was confirmed in Iranian Research Institute of Plant Protection. The mean population density was 70 nematodes per 3g roots and the maximum population was observed at flowering stage. Basket grass is the annual or perennial plant from Poaceae with adventitious root and 10 species in the world. Basket grass is one of the most important weeds in tea plantations moreover main origin of this weed is Iran. The maximum vegetative growth of basket grass occurs in early summer and flowering in the months of May and June. Seed production is in September and October. O. compositus is the most frequent in the eastern parts of tea producing regions in Iran.