Trial Report Summary

The Effect of Seeding Date on Three Varieties of Industrial Hemp in Manitoba

Crop Type(s):
Hemp
Centre(s):
PCDF
Year(s):
2017
Collaborators(s):

Hemp Genetics, Parkland Industrial Hemp Growers, Manitoba Harvest

Objective(s):

To understand the effect of seeding date by variety on industrial hemp grain yields.

Project Findings:

 There was not a significant effect of seeding date on seedling mortality although there was a general trend of greater mortality for the earlier seeding dates. Despite the mortality levels seed densities were still sufficient, with Finola and CanMa averaging 79 and 59 plants/m2, respectively. The exception may have been CRS-1 which averaged 41 plants/m2. Previous work done by the Diversification Centres (2011-2012) demonstrated that grain yield is typically not affected until densities drop below 40 plants/m2. CRS-1 therefore would have had densities right around the threshold where yield may have been impacted.
 The effect of seeding date appears to be variety dependent. All varieties showed a general reduction in both height and grain yield with no interaction between variety and seeding date. However, there was no statistical advantage or penalty detected for seeding until mid June. These results suggest that early seeding, if establishment risk factors (cold, wet soil conditions) are perceived low and the added height at harvest is not an issue can result in greater yield.
 Quality may also be of concern when choosing to seed late, especially for mid and long season varieties such as CRS-1 and CanMa. In this study both varieties expressed decreasing test weights as seeding date was delayed with CanMa being affected the most. Although there was a decrease in yield for Finola when seeded at the end of June, test weight was not effected by seeding date. CRS-1, and especially CanMa had both lower yield and decreasing test weights as seeding was delayed.

Background:

Earlier seeding dates (before May 15) for industrial hemp may result in high plant mortality rates, as well as taller, thicker stems. Limited research is available on the effect of seeding date in Western Canada.

PDF:

Entire findings are available by downloading the report PDF.

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