Abstract:
Potato (Solanum tuberosum L.) is an annual dicotyledonous tuber herbaceous crop. The crop
is relatively susceptible to water stress when compared to other major field crops. Soil texture
plays a pivotal role in the correlative relationship between climate, soil, and vegetation, which
are dependent on soil moisture dynamics and in correlation to vegetation water stress. This
study investigated the effects of water stress and soil texture on potato growth, yield, and
quality attributes. The pot experiment was conducted during the 2021(spring)/2022(winter)
cropping seasons in a plastic tunnel at the University of Venda (UNIVEN) Experimental Farm
situated at Thohoyandou. The experiment was laid out in a Completely Randomized Design
(CRD) with two potato cultivars (Mondial and Bp1), three soil textural classes (clay, sandy clay
loam, sandy loam), and three water stress levels (30%FC (field capacity), 60%FC,100%FC)
with three replicates making a total of 54 experimental units (polyethylene pots). Data collected
was subjected to ANOVA using Minitab 21. Water stress × soil texture interaction had a
significant (p<0.05) effect on plant height at 51 DAP (days after planting) to 72 DAP, and from
44 DAP to 86 DAP during the 2021/2022 cropping seasons, respectively. The interaction of
water stress and soil texture had a non-significant (p>0.05) effect on leaf area. Water stress ×
soil texture interaction had a significant (p<0.05) effect on stem diameter at 93 DAP, and 65
DAP during the 2021/2022 cropping seasons, respectively. There was no significant (p>0.05)
interaction effect between water stress and soil texture on marketable potato yield during the
2021 cropping season, but the interaction had a significant (p<0.05) effect during the 2022
cropping season. This study suggested that severe water stress (30%FC) could be adopted
for potato cultivation in winter season. The tuber sizes and shapes produced during the 2021
cropping season were observed to be smaller (<55mm) and short-oval (1.10 to 1.29) to oval
(between 1.30 and 1.49). However, during the 2022 cropping season tuber sizes and shapes
obtained larger tuber sizes (≥75mm) and long oval (between 1.50 and 1.69) to long (≥1.70).
The specific gravity (1.05 -1.07) was suitable for the potato tubers to be used for processing.
The skin colour of the Bp1 and Mondial cultivars were yellowish, while flesh colours were light
yellow making them suitable for consumers and the market. Therefore, the results suggest
vi
that 30%FC irrigation water level can be economical for production during the winter season
in semi-arid region regardless of the soil texture type (clay, sandy loam, and sandy clay loam).
