Te Kura Horticulture
Horticulture Home
Course Information
Course Information
Horticulture 1000
HT1011 - Practical investigations - Example of an investigation
Processing data and reporting Practice investigation

Example of an investigation


To find out the ideal length of time to stratify peach stones to break dormancy to increase the rate of germination.

Stratification is a method of pre-treating some seed types by exposing them to cold, moist conditions for a period of time. This cold, moist period copies natural processes such as frosty, wet winter soil conditions. It softens the seed coat, triggers the seed embryo to start growing and breaks down or removes chemicals that may stop or slow up germination. The soft seed coat allows water to enter to start the germination process.


Stratified peach stones will germinate faster than unstratified peach stones. Those that have been stratified for the longest period of time will germinate faster than the others.

Equipment needed:

Windfall peach stones from peaches that have ripened and fallen off the tree onto the ground below the tree.
  • four hundred windfall peach stones
  • moist peat/pumice mix
  • refrigerator
  • 4 containers, one for each trial
  • prepared seedbeds outside.

Windfall peach stones come from peaches that have ripened and fallen off the tree onto the ground below the tree.


The unstratified seed.

Variable to be changed

The length of time the seeds are left at 5°C

A 100 peach stones for 120 days
B 100 peach stones for 100 days
C 100 peach stones for 40 days
D 100 peach stones were not stratified

Variables kept the same

  • the cultivar of peach stones (the same type or variety of peach, for example Golden Queen)
  • where the peach stones were collected
  • the temperature they were stratified at – 5°C
  • the type of material the peach stones were placed in during stratification
  • all were stratified in the same refrigerator.


Four hundred windfall peach stones were collected. Four containers were partially filled with a 50:50 mix of moist peat and pumice. 100 stones (peach seeds) were spread out evenly into each container. They were then covered with a layer of peat/pumice. The containers were covered with cling film that had holes in. The film kept in the moisture but the holes in the film allowed air into the container.

The containers were labelled and placed as follows:

  • 120 days and placed in the fridge
  • 100 days and placed in the fridge
  • 40 days and placed in the fridge
  • unstratified (placed at room temperature).

At the beginning of spring the various treatments were removed from cold storage and sown into labelled beds outside. The numbers of seeds that germinated were counted at 10 day intervals.


The following results were recorded of the percentage that germinated.

  0 days 10 days 20 days 30 days 40 days 50 days 60 days
A 0 3 37 60 68 70 71
B 0 2 37 43 46 50 50
C 0 0 0 0 2 9 10
D 0 0 0 0 0 0 0

A labelled line graph is drawn from the data collected.

 Labelled line graph from data collected about stratification of peach seeds.


Chilling assists the germination process in windfall peaches. The longer the peach stones were stratified, the faster the germination rate once they were planted.

What's next?

Go to: 5 Practice investigation.

Processing data and reporting Practice investigation