5.3 Harvesting
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Permission for harvesting
In the Netherlands, every farmer will have to declare crops grown in May (depends on Member State). Before harvesting, the Netherlands Enterprise Agency (RVO) must give its permission. On behalf of RVO, the Dutch Food and Consumer Product Safety Authority (NVWA) will visit the field just before harvest to take samples of each crop. Permission for harvesting is obtained after the NVWA randomly checks the THC content - which is a psychoactive substance - in the plant. This content must be below 0.3% in most EU countries (§3.1).
Harvesting time
Hemp is a fast-growing crop that can be harvested 80-100 days after sowing. To obtain a good fine fibre quality, both for technical and textile applications, harvesting in the Netherlands takes place around the time of flowering (Figure below), from late July to early August. For textiles, the bast fibre has reached the right ratio of strength and fineness around the time of flowering. For technical applications, fineness plays a less important role, but in the northern part of the Netherlands it is not possible to wait until the seeds are fully grown because field retting (§5.4) and drying for storage would no longer be possible for climatic reasons.
Seeds are ripe in the northern part of the Netherlands from about mid-September. By then, the weather in that region is usually so wet that after field retting, it is no longer possible to dry the hemp straw sufficiently to store it in bales. Hemp cultivation in the southern part of the Netherlands is recent and seeds appear to be ripe as early as beginning of September. Considering the regional weather conditions, and if harvesting happens early September, field retting and drying is still possible.
Special harvesters
Harvesting is done with specific machinery, both for technical (§5.3.1) and textile (§5.3.2) applications.
