Poznámky: Agricultural systems I sylabus

Characterization of the Ist and IInd group of cereals
Ist group:
- groove (rýha) is on the bottom side of the kernel
- hollow stalk
- lesser demands for warmth, higher demands for moisture
- winter and spring forms
- rapid initial development
- they need long day (14 - 16 hours) for formation of generative organs (ears)
IInd group:
- kernel is without groove
- stalk is filled by the pith (dřeň)
- higher demands for warmth, lesser demands for moisture
- only spring forms
- slow initial development
- they need short day (less than 14 hours) for formation of generative organs (ears)

Importance and utilization of the cereals
• Cereals were used for people nourishment many thousands year ago:
- easy grain harvesting
- easy storage from harvest to harvest
- possibility of making of reserves
- favourable proportion of basic nutritional matters
- extension in all continents
• Cereals are the oldest culture plants
• Cereals have a decisive position in ecosystem on arable land (they occupy more than 50% of arable land in temperate zone)
• First place among crops in view of importance for people nourishment in the world
• Wide adaptation to environmental conditions of all continents (great genetic and varietal diversity)
• The biggest ability of all plants to use vegetation factors and environmental conditions for the yield formation