Comparing Hemp Seed Yields (Cannabis sativa L.) of an On-Farm Scientific Field Experiment to an On-Farm Agronomic Evaluation Under Organic Growing Conditions in Lower Austria

Abstract Hemp seed yields of the variety Fedora-19 in an on-farm scientific field experiment on small plots and in an on-farm evaluation in 11 hemp fields under practical organic growing conditions in Lower Austria were compared to give a realistic view of the variability of yields. Dry matter seed yields from the on-farm field experiment ranged from 127 to 143 g m−2. Under practical growing conditions, yields ranged from 34 to 151 g m−2 in the sample plots. The reported hemp seed yield after combine harvesting, drying, and cleaning was between 324 kg ha−1 and 717 kg ha−1. The results of the experiment show that harvesting by hand considerably influences yields. Yields of the manual harvest in sample plots indicate a high correlation with yields harvested by the combine harvester (R2 = 0.91). The commercial yield is 71% of the yields recorded in sample plots in the fields. Our data questions the transfer of results and conclusions drawn from the data of scientific field experiments that employ manual harvest to that of practical circumstances, and support the notion of on-farm research.