Seed priming is a method of improving seed performance by preparing (usually with water) the seeds with a specific moisture for a predetermined time and temperature. The preparation starts the germination process but the process is stopped before the seed actually sprouts (no root or shoot). After preparation, the seeds are dried back to normal moisture until needed. The resulting seed will germinate faster and more uniformly than non-primed (raw) seed. The seed will also germinate well over a wider range of temperatures since many of the most temperature sensitive pathways have been completed during priming. Primed seed has been used for many years in protected culture crops like bedding flowers and specialty vegetables and is increasingly used in field grown crops.
Within the wider seed industry, broad adaptation of priming was led by the protected culture flower and vegetable seed industry. Acceptance of priming was relatively quick due to several factors positively impacting the bottom line of the customers. One, priming allowed the growers to germinate primed seeds at lower temperatures in the winter compared to raw seed. This helped to significantly reduce their heating cost in the winter months when greenhouse production is at its peak for spring sales. Two, as the case with many plant species, the completion of germination process can take upwards of 35 days. Priming these slow germinators significantly cuts the germination time down to a few days in many instances. Growers found that the accelerated growth given by priming would result in the ability to get an extra crop out of the greenhouse during a single growing season. Additionally, priming increases usable transplants allowing greater production against a relatively constant overhead meant greater profit per unit greenhouse area. Priming brings tremendous value to the grower and has been the main driver for its wide adaption in the protected culture greenhouse industry.
A barrier to the wider adoption of priming within the seed industry is the perception that primed seed do not store as well as non-primed seed and that the seed quality will significantly decrease if the seed is held over for a second planting season. Post Priming Treatment (PPT) is a recent innovation from Seminis® designed to extend the life of primed seed. PPT is an additional, complementary step done at the end of the priming process before the seed is dried. Not only can PPT improve seed longevity, it can also increase the potential for the seedlings to emerge faster, more uniformly and better equipped to withstand the stresses of a wider range of environmental conditions over only priming and raw seed.
At Seminis®, we offer priming alone or PPT on tomatoes, peppers, onions, and cucurbits.