Quantitative and qualitative changes in the green mass protein of white lupin during the growing season

The aim of the study was to assess the quantitative and qualitative changes in crude protein of the white lupin (<i>Lupinus albus</i> L.) green mass during the growing season in stands of three cultivars of white lupin (ZULIKA, AMIGA, DIETA), intended for feeding purposes as protein roughage, when grown under the same soil and climatic conditions in the Czech Republic. Changes in the crude protein and amino acid content were monitored during the growing season from the 9^th to the 18^th week of stand age. Changes in the crop dry weight were characterised by a statistically significant (<i>P</i> ≤ 0.05) decrease in crude protein from the 9^th to the 15^th week of stand age (ZULIKA 203.50–176.82 g/kg, AMIGA 190.58–161.59 g/kg, DIETA 201.41–175.84 g/kg). In the following period, during the maturation of lupin pods, from the 15^th to the 18^th week, the change in the crude protein content of the green matter was not statistically significant (ZULIKA 176.82–162.12 g/kg, AMIGA 161.59–150.95 g/kg, DIETA 175.84–175.24 g/kg).For most of the amino acids studied, a decrease in their content in the dry weight of the green matter was demonstrated from the 9^th to the 15^th week, with a subsequent statistically significant (<i>P</i> ≤ 0.05) increase from the 15^th to the 18^th week of stand age. Interesting differences were observed in the arginine content, which showed a statistically significant increase (<i>P</i> ≤ 0.05) during the growing season (ZULIKA 7.93–16.03 g/kg, AMIGA 6.88–13.04 g/kg, DIETA 7.56–17.45 g/kg). Changes in the dry weight of the crop in the crude protein and amino acid content can be considered characteristic of lupin crops because of the identical evidence in all three white lupin cultivars studied.