Weeds as alternate hosts of phytonematodes.
Roots and rhizosphere soil of weeds grown in fields of saffron [Crocus sativus], rice, peanut, maize, chilli, tomato, potato, okra, eggplant, banana, peach and apple were analysed for the presence of plant-parasitic nematodes. Twenty eight weed species were found attacked by seven plant-parasitic nematode genera. Eichhornia crassipes, Echinochloa crus-galli, Digitaria ciliaris, Paspalum paspalodes [P. distichum], Cyperus rotundus and Scirpus maritimus acted as both overwintering hosts and summer alternate hosts for Hirschmanniella oryzae. Based on the egg-mass and root gall index, Chenopodium album and Solanum nigrum were good hosts for Meloidogyne spp. Amaranthus blitum, Cirsium arvense, Sonchus oleraceus and Datura stramonium were moderate hosts. Convolvulus arvensis, Cyperus rotundus, Fimbristylis littoralis, Scirpus roylei, Echinochloa colonum, Dactyloctenium aegyptium, Paspalum paspalodes and Sorghum halepense were poor hosts. The importance of weeds in relation to nematodes in agriculture has been discussed.