The turf-type perennial ryegrass, Stadion, was sown in the autumn and spring of 1998 and in 1999 in pure stand and as an undersown crop with spring barley cultivated for green matter and for grain. The intensity of Heteroptera, Homoptera and Thysanoptera pests occurrence in the first year of perennial ryegrass growth for seeds depended on different sowing methods. The plantations set up in autumn showed a greater intensity of the occurrence of Thysanoptera and Aphididae. The perennial ryegrass sowing method affected the intensity of the occurrence of neither Cicadellidae nor Aelia acuminata.

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