Figure 7.

Effect of pulsing cv Maryland White spikes with LaCl₃. Shown are the effects on the kinetics of ethylene evolution (A and B) from longitudinally halved stem sections, cut from their bending zone, on the ethylene-production ratio (C) and on the kinetics of spike curvature (D) during 25 h of gravistimulation. Spikes were pulsed with 20 mm LaCl₃ for 24 h and placed horizontally for an additional 25 h. Stem sections (5 cm long) were excised from the bending zone at the indicated intervals, cut longitudinally into halves, and incubated for 1 h in sealed vials for ethylene accumulation. Points and bars are the averages ± se of seven replicates. LH, Lower halves; UH, upper halves.