EFFECTS OF SEED TREATMENTS WITH GROWTH-RE TARDANTS ON GERMINATION ANDFIELD EMERGENCE OF WINTER BARLEY AND WINTER RAPE

In connection with problems of establishing sowings under faba bean st ands the delay of germination and field emergence of winter barley and winter rape seeds treated with growth retardants was investigated. Se eds were treated with differently concentrated solutions of Etephon, C CC, Tetcyclacis, Paclobutrazol, BAS 111 06, Abscisic acid and IAB 1737 11. Using paperrolls for winter barley seeds and Petri-dishes for wint er rape seeds, respectively, the germination rates were measured. In p ots filled with soil the field emergence rates of both species were de termined. Depending on the retardant and the concentration, the beginn ing of germination in rolls and dishes was delayed up to two weeks. In the pot trials with soil, the delay did not exceed five days. Along w ith this delay often substantial reductions of the final germination a nd the field emergence, respectively, and the dry masses of the seedli ngs occured. Particularly, the final germination percentages of variou sly treated winter rape samples remained below 80 %. Nevertheless prom ising aspects to optimize treatments resulted encouraging further inve stigations.