Die Bodenkultur - Journal for Land Management, Food and Environment
W. AUFHAMMER, E. KÜHLER, P. FLECK, D. RENTEL and Th. MIEDANER:
Synchronisation effects of plant growth regulator treatments on the flowering dates of parental components of winter hybridrye
Field trials were conducted for two seasons (1988/89, 1989/90) to test effects of plant growth regulator applications on the flowering dates of two parental components (CMS single cross, restorer synthetic) of winter hybridrye. Combined with these effects side effects on agronomical traits and seed yield levels and structure were of interest. The CMS-single cross was treated with different concentrations of various growth retardants. In consequence heading dates were delayed up to seven days. Heading of the synthetic was accelerated up to three days by gibberellic acid (GA3) treatments. Concerning flowering dates treatment effects decreased, nevertheless in 1988/89 flowering dates of the used components were synchronized.
As well agronomical traits were influenced by growth regulator treatments.
Growth retardants reduced the shoot length of the CMS-single cross. A triazoletype regulator reduced as well the attack of leaf rust significantly. GA3-applications increased the shoot length of the synthetic. As these treatments reduced ear numbers/m- and ear weights, lodging resistance of the synthetic improved.
In contrary to seed yield levels yield structure of the CMS-single cross was affected by the retardants. Combined with increasing seed numbers/m" thousand grainweights decreased. Contrary effects resulted in consequence of GA3-applications to the synthetic.
Key-words: Hybridrye, seed production, PGR-treatments, flowering date.