Seed collection techniques
If the assessment confirms that a good quality seed collection, of sufficient quantity, can be made from a population, the collector can go ahead and gather seeds.
Charles Ndiege and Desterio Nyamongo of the National Genebank of Kenya, collecting Euphorbia sp. in Kenya's Taita Hills near Voi (Image: Vanessa Bertenshaw, RBG Kew)
Once the collecting team confirms that seed from the target plant species is suitable for harvesting, they collect seed from randomly selected plants at that location. For long-term conservation, seed will be collected from at least 50 individual plants. Up to 20,000 seeds may be necessary for samples to be provided for research, so we collect from many individual plants to avoid harming the plant's future survival in the wild and do not harvest more than 20% of the available seed.
The method for harvesting seed depends on the way in which the plant species naturally disperses its seed. For example, long-handled pruners are used to collect tree seed clustered at the tip of high branches whereas fleshy fruits may be harvested individually by hand into plastic buckets. Seed dispersed by wind is often harvested by rattling branches over a large tarpaulin.
Collectors usually avoid seed lying on the ground as it may have experienced aging or insect attack since it was shed. Pressed plant specimens (herbarium specimens) are taken from one of the plants in seed to confirm identification.