Figure 1.

Methods for drought treatments in the pipe experiment. (A) All seedlings were grown in 30-cm long PVC pipes containing soil, until the first leaves had fully expanded. The drought treatments were then started by placing the 30-cm pipes onto other pipes containing the same soil and continued for 3 weeks during vegetative stage. The final heights of the pipes were either 70 or 100 cm. The control plants were grown continuously in the 30-cm pipe. Throughout the experiment, water was supplied only from the bottoms of the pipes. (B) Plant images after 3 weeks of drought treatment for each of the pipe heights.