Corn seed were treated with pure oxygen and oxygen charge with ozone during 6.8 or 20.5 min. Germination tests were started immediately or 48h after treatment. Effects of oxidative treatments on germination were determinate by measuring seedlings and roots (>3mm and >20mm) rate at 3,4 and 5 days after imbibition. Results obtained for treated seeds samples were higher than untreated one. A faster start of germination for treated samples than untreated was observed. This early germination start led to have more germinated seeds with large root in treated samples than untreated at 4 and 5 days. Never the less a too long ozone treatment seemed to be penalizing on germination rate whereas a short one seemed to be most beneficial.
Various studies have been done documenting the exogeneous oxidative treatment of seeds to break seed dormancy. In addition the positive effects of ozone treatment on germination have also been documented. However the effect of oxygen charged with ozone and their effects on germination have not been studied, specifically in the area of germination conditions and kinetics. Additionally, any improvement in seed germination rate could have profound impact on worldwide food supplies.
250 g of seeds were humidified. In a plastic flask, 26.75 g of distillate water was
added for corn in order to reach 20% moisture content. After 10 min, seeds were
introduced in the reactor and treated with pure O2 ([O3] = 0 g/m3) or an O2/O3 ([O3]
= 20 g/m3) mixture during 6.8 or 20.5 min. After treatment, seed were removed
form the reactor. An half was directly used for germination test. The other half was
stored 48 hrs at 4-deg C before germination test. These experimental conditions
followed a complete factorial design with 3 independent factors (Ozone
concentration, treatment duration, rest time before germination) and repeated factor
(germination test duration). All oxidation treatments were repeated twice.
Treated corn using pure oxygen and oxygen charged with ozone resulted in a faster germination rate vs. control samples. The early germination led to more germinated seeds with larger roots at the 4 and 5 day mark. The presence of ozone in gas treatment improved its effectiveness on corn seed germination and root growth.
El-Purpan, 75 voie du TOEC, 31076 Toulouse Cedex 03, France. ENSIACET, 118 route de Narbonne, 31077 Toulouse Cedex 4, France. Frederic Violleau, Kheira Hadjeba, Joel Albet, Roland Cazalis and Olivier Sure