FAISALABAD: Chief Scientist Aftab Ahmad Sheikh, Incharge Provincial Reference Fertilizer Testing Laboratory Lahore, has taken over the charge of Director Headquarters (HQ) Ayub Agricultural Research Institute (AARI). This seat was vacant for the last one week as his predecessor Riaz Ahmad Gondal had retired after attaining the age of superannuation, said a spokesman for the AARI here on Tuesday. Chief Scientist Aftab Sheikh also served Soil Fertility & Water Testing Laboratory Gujranwala as its Principal Scientist in addition to serving Institute of Soil Chemistry, Research Institute Kala Shah Kaku Lahore as Principal Scientist and Muhammad Nawaz Sharif (MNS) Agriculture University Multan as Director Planning & Development/Registrar.