Research and training in seed technology

Research and training in seed technology

Wageningen University & Research provides top quality research, training and education in seed technology to companies, governmental bodies and NGOs. In doing so we support organisations around the globe in improve and secure seed quality and, therefore, food production. This work is an excellent practical example of Wageningen University & Research’s mission to improve the quality of life.

Good seed quality essential for crop productivity

Seeds are the starting material for most crops and the use of good quality seeds is essential for crops to become established. High quality seeds deliver farmers a higher yield via seedlings with increased stress tolerance, an enhanced ability to compete with weeds and a better use of fertiliser and other inputs. Wageningen University & Research provides research and training in seed technology, and is developing innovative methods for upgrading seed lots and prolonging the shelf life of seeds.

Seeds are the basis of crop production and their quality can be enhanced by knowledge and technology.
Seeds are the basis of crop production and their quality can be enhanced by knowledge and technology.

Seed storage and longevity

In itself it is remarkable that most seeds can be dried, stored and kept alive for a pretty long period of time. Unfortunately, however, the quality of the seeds declines during storage. This deterioration accelerates in moist and warm conditions such as the tropics. For this reason, commercial seed storage for the more expensive vegetable seeds requires relatively cool and dry conditions, with seeds being packed in hermetically sealed pouches.

Vegetable seed companies store seeds in climate-controlled warehouses or pack seeds hermetically sealed to maintain low moisture levels.
Vegetable seed companies store seeds in climate-controlled warehouses or pack seeds hermetically sealed to maintain low moisture levels.

Since farmers do not have access to a climate-controlled room, Wageningen University & Research developed a simple farmers’ seed storage box containing a hygrometer and a desiccant to reduce quality loss.

Wageningen UR developed a seed storage box for small farmers to keep their opened seed packets dry.
Wageningen UR developed a seed storage box for small farmers to keep their opened seed packets dry.

Reducing quality loss during seed storage

Cool and dry storage of seeds is relatively expensive. Moreover, seed companies have no control over the storage temperature when the seeds are at dealers or farmers. Wageningen University & Research scientists showed that seed longevity can be considerably extended by storing dry seeds under oxygen-free conditions. This technology has great potential for storage of seeds with a short shelf life and in the tropics, where cool storage is expensive or not even an option. Read more about Low oxygen seed storage

Primed and pelleted celery seeds (left top corner) have a short shelf life when stored in air (left) but survive very well when stored without oxygen (right).
Primed and pelleted celery seeds (left top corner) have a short shelf life when stored in air (left) but survive very well when stored without oxygen (right).

Genes for improved seed longevity

There is considerable variation between crops regarding how long seeds can remain viable during storage, a factor called seed longevity. Onion and lettuce seeds, for instance, have a relatively short longevity, while barley seeds can be stored for a much longer period under the same conditions. There can also be variation within crops, such as between cultivars. Wageningen University & Research studies which genes are important for seed longevity in rice, barley and in the model plant Arabidopsis.

Rice is the staple food for two-thirds of the world population. Farmers experience a large difference between varieties in the speed of quality loss during storage of paddy rice, which are the seeds to be used for the next crop.
Rice is the staple food for two-thirds of the world population. Farmers experience a large difference between varieties in the speed of quality loss during storage of paddy rice, which are the seeds to be used for the next crop.

A more realistic test for seed longevity

Storing seed in a steel tank under high pressure air or oxygen accelerates seed ageing. This ageing test allows effect of genetic variation or seed treatments to be studied while keeping the seeds dry.
Storing seed in a steel tank under high pressure air or oxygen accelerates seed ageing. This ageing test allows effect of genetic variation or seed treatments to be studied while keeping the seeds dry.

Longevity of seed lots, or shelf life, can vary between different seed production batches or as a result of seed treatments. Priming of seeds, a moist seed treatment to increase uniformity in germination, can have a very negative effect on shelf life. Good shelf life analysis is needed in order to optimise the priming treatment. Since storing under normal commercial conditions takes too long for research purposes, faster tests have been developed in which seeds are stored under moist and warm conditions to accelerate the deteriorating process. However, the physiology of the seeds in moist conditions is very different to when dry – and this causes a low correlation between the test results and the actual shelf life. Wageningen University & Research therefore developed an alternative seed longevity test for storage under dry conditions. The principle is to accelerate the ageing process by storing seeds under increased oxygen pressure while maintaining the moisture levels and storage temperature used in agricultural practice. More about High oxygen seed test

Innovations in seed sorting

By nature plants produce seeds with variations in behaviour and quality, while farmers need seed lots with a high degree of uniformity. An increasing number of techniques are now available for upgrading seed lots via sorting, priming or sanitation treatments. Wageningen UR developed a method for sorting seeds on maturity by analysing the residual level of chlorophyll in the seeds.

Mature seeds tend to contain less chlorophyll as this molecule is degraded during the maturation of most seeds. Sorting seeds on their chlorophyll fluorescence level shows that more mature seeds (lower fraction numbers in the panels on the right) perform much better compared to similar sized, less mature seeds (higher fraction numbers).
Mature seeds tend to contain less chlorophyll as this molecule is degraded during the maturation of most seeds. Sorting seeds on their chlorophyll fluorescence level shows that more mature seeds (lower fraction numbers in the panels on the right) perform much better compared to similar sized, less mature seeds (higher fraction numbers).

Technology transfer

Theory combined with hands-on training. Participants build a home-made priming device during a Wageningen University & Research organised course on seed technology provided in the Philippines.
Theory combined with hands-on training. Participants build a home-made priming device during a Wageningen University & Research organised course on seed technology provided in the Philippines.

An important aspect of improving knowledge about seed quality is technology transfer via training at different levels, from farmers to the academic level and in both the public and private sectors. A good example is the international training module developed by Wageningen University & Research called ‘Capacity development in the application of improved seed technology, to promote high quality seeds’, which takes one week. Others include the Master Class on Seed Technology provided in Wageningen on a post-academic level and various possibilities for training in our lab in Wageningen or with on-site support.