Abstract:
The objectives of this research were to assess the yield response of orange fleshed
sweet potato to water supply at different frequencies; to evaluate how beta carotene
content and nutritional water productivity of orange fleshed sweet potato will be
affected by water supply at different frequencies and; to calibrate and validate the
Soil Water Balance (SWB) model for orange fleshed sweet potato.
A field trial was established in December 2011 at the University of Pretoria
experimental Farm (Hatfield, Gauteng Province), under a rainshelter. The trial
comprised of four irrigation regimes namely, Ttw (irrigated twice a week), Tow
(irrigated once a week), Totw (irrigated once in two weeks) and Tdryl (rain and
supplemental irrigation dependent). Tdryl, an independent field block, was established
outside the rain shelter. Growth and yield analyses were carried out during the
growing season. Irrigation was applied to field capacity (FC), depending on water
required by each treatment, as determined with a neutron probe three times in a
week.
