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

This study examines the relationships between atmospheric influences and gr ain yields as well as yield components: crop density (ears m(-2)), number o f 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 an d 1996. The crop density and kernel number of winter rye were positively in fluenced by warm and sunny weather in autumn. An early start of the sowing 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 o f spikelets and finally to a high number of kernels per ear. The kernel wei ght was negatively influenced by high temperatures and drought during the r ipening stage. This weather situation reduced the duration of the grain fil ling period and thus the kernel weight. The yield of winter rye increased c ontinuously from the mid 1980s as a result of a higher crop density and ker nel number. Probably this is a positive climate change effect.. Particularl y the higher temperatures in winter time and an earlier beginning of the gr owing season seem to be favourable in this context. (C) 2000 Elsevier Scien ce B.V. All rights reserved.