How sustainable is seed priming?

The priming of seeds for agriculture is one of the most powerful techniques in seed enhancement. But you may wonder: how sustainable is it to prime seeds? Looking both at the process itself and the (positive) impact it has, Henry Bruggink, senior research scientist at Incotec, brings you up to speed. You will learn what the most sustainable priming is and how priming helps to combat the consequences of climate change.

How sustainable is the priming process itself?

When priming seeds, it all starts with the priming equipment. In most cases, that will be a drum or a tube. And if the equipment is well made, it can be used over and over again. The electricity and air used for the priming equipment as well as the temperature and light that are part of all priming processes cost extra energy. However, the impact of this on sustainability will be marginal especially if electricity is generated by wind or solar panels. What will have a sustainability impact is the cleaning and disinfection of the equipment, which needs to be done after each priming batch. The impact depends on the kind of materials used, but that it will have an effect is inevitable.

Comparison of seedlings from primed vs unprimed seed

Which type of seed priming is most sustainable?

To answer that question, we first need to look at the type of priming that is used.

Solid matrix

The least sustainable type is priming with solid matrix; the weight of the matrix material is approximately the same weight as the seed that is being primed. Of course, the impact also depends on the kind of material used, but no matter what that is, it cannot be re-used and must be discarded.

Osmo priming

For osmopriming, the kind of material is also important. This is mostly PEG (polyethylene glycol), which can be broken down by microorganisms; disposing of this into the sewer is therefore usually not a problem.

Drum priming

Finally, drum priming, is the most sustainable way to prime seeds, as this only uses water - no osmotics and no matrix. And compared to what you need to rinse off the priming solution after an osmopriming, the amount of water used in drum priming is much less. In cases when other substances are used to get a better priming effect (potassium nitrate, hormones, etc.), drum priming is still the most sustainable method, since all dissolved additives stay on the seed. This is not the case with osmopriming or matrix priming because part of the additives will always be thrown away together with the priming agent.

The summum of sustainability is an organic drum priming, in which only water is used, possibly in combination with physical methods, like varying temperatures, electromagnetic waves (including visible light), ultrasound or plasma-activated water or gas.

Seed priming enhances germination speed and uniformity, reduces seed waste and fosters resilience against climate-induced stresses.

What are the sustainability gains of priming?

We must also consider the sustainability gains achieved through priming. Seed priming emerges as a sustainable agricultural tool because it enhances germination speed and uniformity, reduces seed waste, and fosters resilience against climate-induced stresses. As an example, priming of tomato seeds results in a faster and more uniform germination, meaning that seedlings reach the desired size sooner so their duration at the plant raiser is therefore shorter. With an increase in the percentage of useable transplants, the plant raiser also needs to sow fewer seeds, thus less greenhouse space is occupied, and less sowing material is needed. And a more uniform crop, in turn means easier and more efficient plant management at a later stage.

Does priming help to mitigate the effects of climate change?

With the changing climate, there can be an increase of abiotic stress, like heat and drought, in the open field. Therefore, a more resilient crop is needed. Priming can play a significant role here. Primed seed has a faster germination and earlier plant establishment; consequently, germinating seeds and very young seedlings will be exposed to unfavorable weather conditions for a shorter time.

Priming enhances agricultural efficiency and is a sustainable approach to addressing the challenges posed by climate change

In addition, primed seed will also germinate better under stressful conditions. For example, a lower temperature for tomato seed, or a higher temperature for lettuce or celery seed has little or no effect on the emergence when the seed has been primed.

In conclusion, while seed priming enhances agricultural efficiency and represents a sustainable approach to addressing the challenges posed by climate change, the type of seed priming used and its impact on sustainability must also be considered.