Effect of time of fungicide application on the second harvest seed yield of five cocksfoot (Dactylis glomerata L.) cultivars

Abstract

The effects of time of fungicide application on seed yield and its components were determined for second harvest plots of three New Zealand (Grasslands Wanan, Grasslands Kara, Grasslands Tekapo) and two Japanese (Akimidori, Makibamidori) cocksfoot (Dactylis glomerata L.) cultivars. Tebuconazole (188 g a.i. ha-1) was applied either at ear emergence, at ear emergence plus anthesis, and anthesis plus 10 days post anthesis. Disease incidence was <1% for all cultivars, but fungicide treatments significantly increased the percentage green area of the flag leaf, leaf two and leaf three, plus the stem. Seed yield was significantly increased by the ear emergence fungicide application in cv. G. Wana, G. Tekapo and Makibamidori, and by the ear emergence plus anthesis applications in cv. G. Wana, G. Kara, Akimidori and Makibamidori. These yield increases ranged from 14% (cv. G. Kara) to 43% (cv. Makibamidori), and were associated with increased floret site utilisation and increases in thousand seed weight, although these responses were not consistent for all treatments or cultivars.