Abstract:
The Johnson grass is very good adapted to a wide range of soils,
climatic and biological conditions. In the presence of some agrochemical,
chemical, biological and physical factors. Staring from this issue in the
present work we studied the biological modifications which occur in the plant
of Sorghum halepense growth in BBCH stages 10 – 69. Also total N, protein,
P and K content in rhizomes, steam, leaves and panicle was determined. The
chemical analyzes was conducted after a reported method, the N quantity
was established after Kjeldahl method the amounts of P and K was
determinate using the colorimetrical method. After chemical analysis the
result reveals that the highest total N quantity is present in the first growth
stages. The N total content varied between 0,450% and 2,442%, and the
highest concentration was determined in BBCH 18.Potassium content in
Johnson grass plants ranged between 0,8% and 3,95%. For phosphorus
content great fluctuation were not recorded, (0,3 – 1,0).