TABLE 2.

A summary of the effects of drought stress on key physiological canopy traits in potato and the range of methodologies by which these variables were manipulated.

References	Aliche et al., 2018	Chang et al., 2018	Deblonde and Ledent, 2001	Jefferies, 1993b	Jefferies and MacKerron, 1987	Lahlou et al., 2003
Observations	Decreased canopy growth rate, fewer new leaves, premature leaf shedding.	Decreased stem length.	Reduced leaf number, reduced stem height.	Reduced individual leaf area.	Reduced leaf growth.	Reduced stem number.
Cultivar	103 commercial cultivars.	Chubaek, Superior, Jayoung.	Eersteling, Jaerla, Krostar Eersteling, Claustar, Bintje, Nicola, Désirée.	19 commercial cultivars.	Maris Piper, Record, Désirée, Pentland Crown, Pentland Dell, Pentland Squire.	Remarka, Dérirée (field and greenhouse); Nicola, Monalisa (field only).
Culture method	Field	Field	Field	Field	Field	Field (Remarka, Désirée, Nicola and Monalisa) Pots (Remarka and Désirée).
Drought conditions	Rainfed.	Rainfed until emergence and then totally deprived of water until tuberization. After tuberization, plants were irrigated when indicators of drought stress were visible (“wilting and growth retardation”).	Deprived of water by a plastic sheet at 50% emergence for 8 weeks.	Deprived of water by a mobile rain shelter from emergence to harvest.	Deprived of water by polythene sheeting laid over the plants from emergence to harvest.	Rainfed in the field. Irrigated to field capacity when soil moisture dropped below −0.8 MPa in the pots.
Control	Rainfed plus irrigated with roughly 15 to 30 mm of water on 14 occasions.	Predominantly rainfed, irrigated with trickle irrigation between May and June during a dry period. Plants were irrigated when indicators of drought stress were visible (“wilting and growth retardation”).	Rainfed only or rainfed plus 37 and 35 mm of irrigation in 1996 and 1996, respectively.	Rainfed plus sprinkler irrigation to maintain a soil moisture deficit of <25 mm.	Rainfed plus trickle irrigation to maintain a soil moisture deficit of <30 mm.	Irrigated with 20 mm five times throughout the season in the field. Irrigated to field capacity when soil moisture dropped below −0.3 MPa in the pots.