Difference Between Vernalization and Stratification

The key difference between vernalization and stratification is that vernalization is a treatment that is used to promote flower initiation, while stratification is a treatment that is used to break seed dormancy.

Vernalization and stratification are two important techniques associated with plants. Vernalization accelerates early flowering while stratification breaks seed dormancy. Thus, both types of techniques are similarly useful in agriculture. Moreover, both processes involve cold treatments. Apart from that, stratification involves warm conditions as well.

CONTENTS

1. Overview and Key Difference
2. What is Vernalization 
3. What is Stratification
4. Similarities Between Vernalization and Stratification
5. Side by Side Comparison – Vernalization vs Stratification in Tabular Form
6. Summary

What is Vernalization?

Vernalization is a low-temperature treatment that induces and promotes early flowering in flowering plants. In fact, it is a prolonged, low-temperature treatment done for the plant shoot apex. It eventually shortens the vegetative phase of the plant and helps to increase the fruit set and yield. Furthermore, vernalization enhances the plant resistance to cold temperatures. Therefore, winter varieties can be converted into spring varieties. Vernalization also increases plant resistance to fungal diseases. And, this technique is one of the best options in horticulture when grafting a vernalized shoot apex with that of a non-vernalized one. Moreover, vernalization is a method of crop improvement. It reduces the cost of crop production. Also, it facilitates growing more than one crop in the same season.

Several factors affect the efficiency of the vernalization process. These include the age of the plant, availability of oxygen, energy source, duration of the cold treatment and water. Thus, based on these factors, the percentage of flowering may change. Gibberellin is one of the plant hormones that can replace this technique.

What is Stratification?

Generally, seeds have dormancy periods. Thus, they require certain conditions to germinate. Therefore, it is essential to provide those conditions properly to break dormancy to promote seed germination.  Stratification is a technique that can break the dormancy in seeds and promote seed germination. Besides, this technique involves both cold and warm stratification since some seeds yield warm and moist conditions while other seeds need cold and wet conditions. Apart from that, some needs need a combination of both cold and warm treatments. Thus, the stratification process varies based on the type of seed.

Cold stratification is the type of stratification in which seeds are subject to both cold and moist conditions. On the other hand, warm stratification requires temperatures of 15-20°C.  In most instances, warm stratification is followed by cold stratification.

What are the Similarities Between Vernalization and Stratification?

• Vernalization and stratification are two techniques involved in plants.
• Both techniques use cold temperatures.
• They are important processes in agriculture.

What is the Difference Between Vernalization and Stratification?

Vernalization is a cold treatment that induces the flowering and reduces the vegetative phase of the plants. Meanwhile, stratification is a cold or warm technique that breaks the dormancy of seeds to increase seed germination. So, this is the key difference between vernalization and stratification.

Moreover, a further difference between vernalization and stratification is that vernalization involves only cold treatment, while stratification involves both cold and warm stratification.

Below infographic summarizes the difference between vernalization and stratification.

Summary – Vernalization vs Stratification

Vernalization is the process that promotes flowering while stratification is the process that promotes seed germination by breaking the seed dormancy. Thus, this is the key difference between vernalization and stratification. In vernalization, shoot apexes subject into prolonged cold temperatures while, in stratification, seeds are soaked in water for one or two days.

Reference:

1. Scarification and Stratification, The Gardeners Almanac, Available here.
2. “Vernalization.” Wikipedia, Wikimedia Foundation, 25 June 2019, Available here.

Image Courtesy:

1. “Hyoscyamus niger Hullukaali Bolmört C IMG 7657” By Anneli Salo – Own work (CC-BY-SA 3.0) via Commons Wikimedia
2. “2007. Stratified whitebark pine seeds ready for scarification. Dorena Genetic Resource Center. Cottage Grove, Oregon.” By R6, State & Private Forestry, Forest Health Protection (Public Domain) via Flickr