Harrowing timing for winter wheat and spring barley under organically growing conditions
Lithuanian Institute of AgricultureInstituto Alėja 1, LT – 58344, Akademija, Kėdainiai distr.; e-mail: email@example.com
Field trials were conducted over the period of 2005–2007 at the Lithuanian Institute of Agriculture to test the efficacy of harrowing on weeds at different growth stages of ecologically grown winter wheat and spring barley. The main weeds in winter wheat were: Lamium sp., Chenopodium album, Tripleurospermum inodorum, Capsella bursa-pastoris and in spring barley Ch.album, Sinapis arvensis, Stellaria media, T. inodorum. The weeds most vulnerable to harrowing in winter wheat were: Veronica sp., Chenopodium album and Capsella bursa pastoris. Chenopodium album and Sinapis arvensis were vulnerable to harrowing in spring barley. Early harrowing pre-emergence followed with harrowing at the 3–4 leave stage of spring barley was the most optimal.Winter wheat grain yield reduction tendencies were obtained in plots harrowed threetimes. No statistical difference in spring barley grain yield was found among the treatments. The decrease in weed number and mass depended on harrowing timing and frequency, meteorological conditions and weed species composition.