Emergence of wheat may be reduced by seed weather damage and azole fungicides and is related to coleoptile length

Abstract

Seed germination, seedling emergence and coleoptile length of sound and weather-damaged seed of 8 wheat cultivars, which had been treated with twice the recommended rates of the seed dressings Le-san E11, Pano-ram 25, Vitavax 750L, Baytan and Erex, were studied in a sand-perlite substrate at 13¦C and in 2 field experiments. Germination was not affected by the dressings. Baytan and Erex delayed and reduced the emergence of all cultivars at 13¦C, but in the field only some cultivars had emergence reduced by seed dressings. Weather damage reduced the germination of some cultivars but the results were not consistent. The emergence of damaged seed of some cultivars was further reduced by Baytan and Erex when sown deeply in dry soil. In the cvv. Banks and Osprey, weather damage and Erex shortened coleoptiles of seed that was germinated on moist soil in darkness at 13¦C. Emergence was positively related with coleoptile length, and, in the controlled environment test, it declined markedly when coleoptiles were less than 5 cm.