Will growth characteristics describe yield differently in different environments?

Summary

The growing interest in organic farming has increased the interest in examining if different growing characteristics among varieties would explain differences in yield differently in conventional compared to organic systems. This work will focus on that question. The analyses are performed using data from trials with spring barley in Denmark and Sweden. Growing characteristics on diseases, volume weight, grain weight, and lodging will be included in the work.
The growing characteristics are included as covariates to see how much of the variation caused by varieties and interaction with varieties that can be explained by the growing characteristic. The model is setup in order to estimate simultaneously the effect of the growing characteristics and the possible interactions between those that can be expected to interact.
The analyses showed that the relation between yield and the growth characteristics volume weight or grain weight depended on the growing system but in different ways in the two countries. The relation between yield and the disease powdery mildew were stronger in the conventional grown trials than in the organic grown trials. There was a tendency for the same difference to apply for the diseases leaf rust, net blotch and scald in Danish trials and net blotch in Northern Sweden, but not for scald in Northern Sweden. None of the tendencies were significant at the 5% level.