Radio play where the protagonist uses a lance grown from a seed to fight against a giant with three swords

Question

Around 15 years ago I listened to a German audio recording of a fantasy story for kids (I was between 7-9 at the time). The recording was saved as a file on my computer so I'm unsure about the original format.

Story

As far as I remember the story is about a boy from a little village who goes on a quest to fight the giant that oppresses the land (something along those lines).

In the beginning, he talks to someone in the woods who gives him a plant seed of some sort and tells him that it will fully grow overnight once he plants it. I believe he later takes the grown plant on his journey as a lance/spear.

After that, I'm drawing a blank until he confronts the giant. The giant has three different swords of varying weight.

I distinctly remember the usage of the weight unit Pood here.

The swords weigh:

1. 7 pood
2. 7 times 7 pood
3. 7 times 77 pood

The giant tries to break the protagonist's lance with his swords but fails. I remember the following lines of dialogue (word by word in German, I will try to translate as accurately as I can):

• Giant:

  GER: "[...] Sieh dir mein drittes Schwert an [...] , sieben mal siebenundsiebzig Pud"

  ENG: "[...] Take a look at my third sword [...] , seven times seventy-seven pood"

• [The giant tries to smash the lance]

• Protagonist:

  GER: "Ein Glück, die Lanze hat standgehalten!"

  ENG: "How fortunate, the lance withstood!"

Answer 1

Could this be a variation of the tale of Ivan Popyalof?

Based on John Rennie's comment, I searched for Russian fairy tales that contained the keywords pood, lance, sword, and giant and came across this story. The story has several key elements you describe, although overall this version is rather different.

• The protagonist is a young boy named Ivan
• He slays the antagonist who oppresses the land, although it is a snake and not a giant
• The story does features three weapons of increasing weights, although
  • Ivan is the one who uses them
  • They are maces, not swords
  • They are made by his father, not a magic plant
  • The weights are multiples of 5, not 7
  • I couldn't find anything resembling the dialogue you remember

Answer 2

I found it! The adventures of strong Vanya by Ottfried Preußler (1968)

Found it via Google with the following query:

Geschichte Ivan Lanze

Thanks to @MJD for the valuable hint that the story might be based on the tale of Ivan Popyalof. Many elements of the two stories overlap.