The root images were analysed with the digital image analysis programme RD (Root Detector, ETH Zurich, Switzerland) (Walter and B¨urgi, 1996). The dry matter of the leaves, shoots and roots was determined separately after drying at 65 ◦C for 42 h
The root images were analysed with the digital image analysis programme RD (Root Detector, ETH Zurich, Switzerland)(Walter and B¨urgi, 1996). The dry matter of the leaves, shoots and roots was determined separately after drying at 65 ◦Cfor 42 h