Efficiency of Potassium in Barley Genotypes

The variation in potassium uptake and utilization by Bulgarian malting barley genotypes was studied. Four varieties such as Obzor (state standard), Emon, Kaskadior and Krami and ten perspective breeding lines, selected by the Department of Genetics and Breeding at the Agricultural University-Plovdiv, were studied. It was established that the potassium concentration of straw was two times higher than the grain potassium concentration. Variety Krami and lines 17, 18, 31, 44 were distinguished with higher content of potassium in grain and variety Krami and lines 24 and 44 had higher straw potassium content. Accumulated potassium in straw represented eighty percents of the total potassium uptake in maturity. Kaskadior was characterized with the highest potassium harvest index and the lowest expense for 100 kg grain - 26.8% and 2,5 kg K2O, respectively. Cultivar Emon and line 29 used most efficiently potassium for biomass and grain formation, and variety Krami and line 44 demonstrated the lowest values of KUEb and KUEg. The rest of the studied genotypes showed lower potassium use efficiency related to standard variety Obzor. A strong positive correlation was established between KUEb and KUEg with KHI, and between KUEg and KUEb. The efficiency of potassium use for biomass and grain was negatively related to the straw yield, the concentration and content of potassium in straw, the total potassium uptake and the expense of potassium for 100 kg grain