Fig. 2.

Photograph showing the experimental set up. 20 mL glass headspace vials were filled with 1 g of seeds (seeds pictured are Lolium perenne) which had been equilibrated to 60% RH. Control vials (left) contained just seeds and an oxygen indicating tablet, which was blue/purple in the presence of oxygen (> 0.5%) and turned to pink when oxygen levels were < 0.1%. Other vials (second from left to right) contained seeds, an oxygen indicating tablet and either a 20 cc oxygen absorber (O₂ absorber), a 20 cc oxygen absorber and a silica gel sachet (O₂ absorber + silica), or a silica gel sachet which had been pre-equilibrated to 60% RH (silica). All vials were sealed with PTFE-lined crimp seals