Grasshoppers have caused significant defoliation in Alberta research plots. Cutworms and European corn borer have been reported on hemp. Sucking insects, such as stink bugs and lygus plant bugs, can cause seed yield reduction and could spread disease. Other Concerns Black birds have caused significant grain loss to mature hemp plants in areas near lakes and sloughs. Wind and hail damage can also be a problem in tall crops due to bent and broken stems.
Some growers report the removal of individual hemp plants by inquisitive persons.
Possession of immature hemp plants without a license is illegal. This is done by hiring the services of a person approved by Health Canada as a hemp sampler. The sampler must follow the Health Canada guidelines outlined in the Industrial Hemp Technical Manual to collect samples, dry them and submit the samples to an approved laboratory for analysis. The laboratory analysis determines the level of THC found in the crop sample and provides a report to the grower. The form for Reporting of results of Delta-9 THC testing of Industrial Hemp is also available from the Heath Canada website.