Chlorophyll Concentration (Spad Values) as an Indicator of Crude Protein Content and as a Selection Criterion in Grass Breeding

The main aim of the study was to analyse chlorophyll a + b content (SPAD values) determined by portable chlorophyllmeter (SPAD- 502, Minolta, Japan) and crude protein content in leaves of timothy, coocksfoot, perennial ryegrass and meadow fescue (total 24 cultivars). Differences between both parameters were confirmed and a close relationship between chlorophyll content (SPAD values) and crude protein concentration was found. Correlation coefficient between SPAD and crude protein varied from 0.541++ for ryegrass to 0.906++ for timothy. This fact should be used for selection of grasses with higher crude protein content and/or better use of mineral soil nitrogen