The use and degradation of radiant energy in water-stressed wheat (Triticum durum Desf. ssp. enduró) was examined by the fluorescence quenching, absorbance changes around 830 nm due to P700 oxidation, and the gas exchange parameters. Under water stress, P700 accumulated in the photochemically inactive oxidised form especially at a high irradiance.
Measurements of the proper niotlons of young blpolar sunspot groups show that these groups rotate faster than the surroundlng photosphere. The results of the tlme series analysis carrled out on the Irradiance records of the SMM/ACRIM radiometer and on the projected areas of the young, active sunspot groups showed a period near U days In 1980, the year of the solar maximum. The main period in the projected areas of the old sunspot groups was 28 days, which corresponded to the mean photospherlc rotatlon. The faster proper motlon of the young sunspot groups as well as the 24 days periodicity of the young active spot areas might indicate that the young sunspots are connected to the deeper regione of the Sun which rotate faster than the photosphere. Thus, the sunspot groups in the early stage of their life would be an indlcator of rotation of the deeper layers of the Sun.