As both drug cannabis and hemp cultivation proliferate, agronomic challenges lurk on the horizon.
In Europe and North America, hemp fiber crops have traditionally been harvested upon reaching technical maturity when the male plants begin to shed pollen. In eastern Asia, hemp fiber crops destined for fine textile production are harvested before they flower, and therefore no pollen or seed is produced. No flowers, no pollen and no problems. The timing of a fiber crop harvest—either before or after it releases pollen—determines whether it poses a threat to neighboring sinsemilla cannabis growers. Depending on cropping techniques, fiber hemp production can be compatible anywhere. The real issue is not about hemp fiber production but seedless drug cultivation. However, the situation differs with hemp seed crops.
Hemp seed crops are grown specifically for seeds sold primarily to the food and body-care industries. Hemp seed and seed oil are more in demand than at any other time in recent history, and the profitable growing of hemp seed is increasing at suitable temperate latitudes worldwide. Based on their common environmental needs, seedless drug cannabis thrives in the same agricultural niches as hemp seed crops, and this can lead to competition between these agronomically incompatible crops.
Long-distance Cannabis pollen transport is well-documented. A single male Cannabis plant can produce millions of pollen grains that are easily carried on the wind. Each summer, allergenic pollen traps installed along the Mediterranean coast of southern Spain collect Cannabis pollen that drifts across 100 miles of open sea from hashish fields in the Rif Mountains of Morocco.
Field-grown hemp seed crops are agronomically and economically incompatible with drug cannabis crops, and growing them within the range of pollen travel will likely result in conflicts. Even Cannabis plants grown in greenhouses and grow rooms can become fertilized by pollen that enters through the ventilation system. It is of note that during the early days of industrial hemp cultivation in the Netherlands several indoor and glasshouse sinsemilla growers reported finding seeds in their normally seedless crops. (Tip: High-efficiency particulate air (HEPA) filters effectively remove pollen from air intakes in sealed grow rooms.)
In the sinsemilla setting of zero tolerance for seeds, long-range pollen drift, especially outdoors, sounds frightening. Reactionary voices within the cannabis community have raised the alarm, but is there a real threat? How are the cropping strategies of growing seeded hemp cultivars for their CBD content versus growing seedless drug varieties for THC and/or CBD content playing out across North America and worldwide?