Schoolboy Petya Ivanov receives a letter from a famous scientist and 20 grains of a new high-yield variety of wheat. Petya and his schoolmates decide to create an experimental plot. Fearing that adults will take the seeds away from them, the children do everything in secret.
| Actor | Role |
|---|---|
 Boris RyzhukhinNot listed | Not listed |
| AArina BedrintsevaNot listed | Not listed |
 Pyotr LobanovХаритон Семенович | Харитон Семенович |
| NNatalia RodionovaNot listed | Not listed |
| SStepan KolchuginNot listed | Not listed |
 Eduard BredunVasiliy | Vasiliy |
 Natalya RashevskayaKlavdia Vasilyeva, teacher | Klavdia Vasilyeva, teacher |
| SSergei PodmasteryevPetya | Petya |