Impact of weather on yield components of winter rye over 30 years

This study examines the relationships between atmospheric influences and grain yields as well as yield components: crop density (ears m−2), number of kernels per ear and kernel weight of winter rye. The study uses data of a long-term field experiment at Berlin-Dahlem for the period between 1962 and 1996. The crop density and kernel number of winter rye were positively influenced by warm and sunny weather in autumn. An early start of the growing season after winter was also important for the satisfactory development of these components. Moderate temperatures prior to the beginning of shooting prolonged the period of spikelet formation and led to an increased number of spikelets and finally to a high number of kernels per ear. The kernel weight was negatively influenced by high temperatures and drought during the ripening stage. This weather situation reduced the duration of the grain filling period and thus the kernel weight. The yield of winter rye increased continuously from the mid 1980s as a result of a higher crop density and kernel number. Probably this is a positive climate change effect. Particularly the higher temperatures in winter time and an earlier beginning of the growing season seem to be favourable in this context.