Document Type : Research Paper
Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
Ardabil Agricultural and Natural Resources Research Station, Ardabil, IRAN
In Ardabil region potato crop needs several irrigation, however ground water supplies are
being exhausted due to reduced precipitation and intensive irrigation. In this research drought
tolerance of 10 commercial potato cultivars was studied at three irrigation treatments (100%,
80% and 60% of required irrigation water) in Ardabil in a two years field study, 2013-2014.
At harvest, marketable tuber yield, tuber weight per plant, mean tuber weight, tuber number per
plant, percent tuber dry matter, plant height and the main stem diameter were measured. Also
the stress indices such as water stress susceptibility (SSI), tolerance (TOL), mean productivity
(MP), geometric mean productivity (GMP) and stress tolerance (STI) were determined and used
to select the tolerant cultivars to water deficit. There were significant differences among
irrigation treatments, cultivars and cultivars × irrigation treatments for all studied traits; between
years and interaction of years × cultivars for marketable tuber yield, tuber weight per plant,
mean tuber weight and tuber numbers per plant. The cultivar Satina produced the highest
marketable tuber yield, tuber weight per plant, mean tuber weight and plant height and also had
higher MP, GMP and STI indices in all three irrigation treatments, therefore, it can be
recommended for cultivation under water deficit condition. Cultivar Caesar showed the lowest
SSI and TOL indices under both mild and severe water deficit conditions, therefore it can be
used in breeding programs for developing drought–tolerant potato cultivars. Under both mild
and severe stress conditions a high correlation was found between marketable tuber yield and
plant height, but a negative correlation existed between mean tuber weight and tuber number per
plant. Cultivar Savalan showed the highest tuber dry matter content.