Comparative Study of Salinity and Growing Season Effects on Potato (Solanum tuberosum L.) Quality

The secure exploit of saline water to successfully grow crops became a major challenge for areas suffering from water salinization, especially during the dry season. A field experiment was conducted to investigate the effect of salinity (C: Ground water 2.2 mS cm−1 electrical conductivity (EC); SW: Saline water 8.50 mS cm−1 EC and EMW: Electromagnetic saline water 8.50 mS cm−1 EC) and growing seasons (S1: Autumn; S2: Spring) on tuber yield, physicochemical and quality characteristics of three potato varieties (Spunta, Bellini and Aalska) under Tunisian semi-arid conditions. Results revealed that tuber yield and the amount of marketable yield were least under SW with a significant increase under ESW for both seasons. Across varieties, it seems that Spunta was more productive in S2, while Alaska was more adapted to S1. The number of tubers greater than 55 mm was higher in Alaska. However, the augment of marketable tubers amount under ESW was not evident in Bellini grown in S2. On the other hand, the dry matter of Spunta and Alaska was higher in S1. All tested varieties were significantly susceptible to ascorbic acid loss under saline irrigation. Nonetheless, the enhanced total sugars with ESW are significant only in S1. It is concluded that potato varieties’ response to salinity depends on growing season. The autumn season is more suitable for potato cultivation under saline semi-arid climate conditions.