Spatiotemporal variability and sensitivity of industrial hemp cultivars under variable field conditions

Abstract

The study of the impact of climate change on crop production requires the examination of cultivar adaptation and performance in response to interannual variability in climate and field conditions. A field test was carried out during four years in Eastern New Brunswick, Canada, to study grain yield, fiber yield and floral cannabidiol content of eight Canadian industrial hemp (Cannabis sativa L., Cannabaceae) cultivars. Hemp performance in terms of grain and fiber production varied greatly between the years. The spatial location of plants in the field was shown to affect the performance of cultivars in different ways for grain and fiber yield. Grain yield was the highest in hot and humid summers, the opposite was observed for cannabidiol content, while fiber production was the highest in cold and humid summers. Our results indicated that grain, fiber or cannabidiol production cannot all be optimized under the given set of climatic conditions and that hemp performance is more sensitive to interannual variability of climatic conditions and intra-field variability than to cultivar effects. Yet, despite the considerable spatiotemporal variability documented, some cultivars have repeatedly exhibited the best performance, demonstrating excellent adaptation to local field conditions.