Two field experiments concerning potato (Solanum tuberosum L.) crop were
carried out during two successive winter seasons of 2009/2010 and 2010/2011 in a private farm at
a newly reclaimed area, in El-Amria region, Alexandria governorate, Egypt. The experiment was
performed to study the effect of hydrogen peroxide (H2O2) on the potato processing quality and the
economical characters. The split-plot design in three replicates was used, where potato cultivars
were placed in the main plots, while doses of foliar spraying with hydrogen peroxide were occupied
the sub-plots. Three potato cultivars were tested in this investigation; Lady Rossetta, Valor and
Mondial. Four doses of hydrogen peroxide were used as zero, 25, 50 and 75 mM in the first year.
Two higher doses, 100 and 125 mM of hydrogen peroxide were added in the second year. Potato
plant stem diameter was positively affected with the increasing of H2O2 concentrations from zero up < br />to 125 mM. The results showed that the 25, 50 and 75 mM of H2O2 concentrations did not affect the
potato tuber yield. The other two high levels (100 and 125 mM) of H2O2 resulted in lower potato
yields. The number of tubers/ 10 Kg weight trait seemed to be affected with H2O2 concentrations, in
which it was above the accepted number during the second year (more than 112 tubers/10 Kg
weight).In the first year, the data indicated that spraying potato plants with 75 or 50 mM of H2O2
significantly increased dry matter percentage compared with the control treatment. Both treatments
of 75 and 50 mM of H2O2, produced the highest levels of tuber starch content in the first year , while
the treatment 75 mM of H2O2, produced the highly tuber starch content with significant differences
among the other tested treatment in the second year of the study. The effect of hydrogen peroxide
on parenchyma cell diameter trait differed from year to another. The treatment of 50 mM of H2O2
possessed the highest value for parenchyma cell diameter trait, whereas, the treatments of both 25
and 125 mM of H2O2 increased the parenchyma cell diameter trait. The lowest chipping defects
were produced when potato plants sprayed with 50 mM H2O2. The control treatment gave the
lowest mean value (result) where this treatment produced highly significant level of tuber chipping
defects.