Sweet potato plants were grown at EI- Bramoon Agricultural Farm of EI-Mansoura
Horticultural Research Station, during the two successive seasons of 2002 and 2003,
to study the influence of foliar nutrition with a mixture of some micronutrients, bio-
phosphate fertilizers, i.e., Phosphorein and VA-mycorrhiza, and mineral phosphate
fertilizer at 0, 30, 45 and 60 kg P20slfed., on quality features and organic composition
of three months stored tuber roots, under room conditions. Results showed that the
use of micronutrients significantly decreased weight loss percentage during storage
period, in both seasons, and sprouting percentage, in the second season only.
However it did not affect decay percentage, in both seasons, or sprouting percentage,
in the first season. Increasing P-rate significantly reduced weight 10f s, decay and
sprouting percentage during storage period. Roots of plants inoculated with VA-
mycorrhiza recorded the lowest percentage of weight loss, decay and sprouting
percentage, during the three months of storage period.
Organic composition, Le., dry matter %, total carbohydrates, reducing and non-
reducing sugars and total carotenes of stores tuber roots, increased significantly, in
both seasons, as a result of treating plants with micronutrients, by increasing P-rate
from 30 to 60 kg P20slfed. and by inoculating plants with bio-fertilizers, either VA-
mycorrhiza or Phosphorein. Positive interactions between main factors were often
detected, with the best results obtained by using 45 or 60 kg P₂0slfed. in the
presence of micronutrients and VA-mycorrhiza.