Weather and yield

Abstract

Based on long-term (1997 - 2017) meteorological measurements and agricultural observations on an experimental field of Julius-Kühn-Institute - Federal Institute for Research on cultivated plants - located in Dahnsdorf (municipal of Planetal, administrative district of Potsdam-Mittelmark, federal state of Brandenburg) relationships between weather and yield on winter-wheat were analysed. Enormous studies of literature were included. Aim was to find meteorological and growth parameters that are relevant for yield. For this reason crop year was divided in ten growth-orientated vegetation phases. For each vegetation phase meteorological and growth parameters were determined that were relevant for yield. It was carried out by two different methods: in method I effects of preceding vegetation phases were not considered, in method II they were included. In this mentioned ten vegetation phases up to six parameters could be detected by both methods. These parameters were relevant for yield and differed between mentioned methods. The number of parameters was often lower in method II. Linear models of yield derived from this method are better adapted but they are strongly influenced by previous vegetation phase. Depending on included data of the analyzings instabilities emerge concerning important yield parameters and fitting a belonging model of yield. Inclusion of different (long-term) periods of time leads to different significant parameters. On the other hand adaption of the model of yield can be improved by selecting of initial parameters. Useful was the predetermination of initial parameters that were adapting to the growth of vegetation and meteorological conditions during respective vegetation phase.