Water stress preconditioning to improve drought resistance in young apricot plants

• Published in: Plant science (Limerick) Vol. 156; no. 2; pp. 245 - 251
• Main Authors: Ruiz-Sánchez, M.C, Domingo, R, Torrecillas, A, Pérez-Pastor, A
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 28.07.2000; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Gas exchange; Osmotic adjustment; Plant hardening; Plant physiology and development; Prunus armeniaca; Water and solutes. Absorption, translocation and permeability; Water relations; Water relations, transpiration, stomata; Water stress; Plant hardening; Ψ os, leaf osmotic potential at full turgor; Ψ p, leaf turgor potential; θ v, volumetric soil water content; P n, net photosynthesis; Ψ m, soil matric potential; Ψ md, mid-day leaf water potential; Water stress; T c− T a, canopy to air temperature difference; Water relations; TDR, time domain reflectometry; Osmotic adjustment; LIA, leaf insertion angle; Prunus armeniaca; g l, leaf conductance; Ψ pd, pre-dawn leaf water potential; Gas exchange; Ψ o, leaf osmotic potential; Rosaceae; Osmoregulation; Water regime; Drought resistance; Dicotyledones; Angiospermae; Stomatal movement; Spermatophyta; Fruit tree; Pretreatment; Adaptation
• DOI: 10.1016/S0168-9452(00)00262-4
• ISSN: 0168-9452

The effect of water stress preconditioning was studied in 1-year-old apricot plants ( Prunus armeniaca L., cv. Búlida). Plants were submitted to different treatments, T-0 (control treatment) and T-1, drip irrigated daily; T-2 and T-3, irrigated daily at 50% and 25% of T-0, respectively; T-4 and T-5, irrigated to field capacity every 3 and 6 days, respectively. After 30 days, irrigation was withheld for 10 days, maintaining the T-0 treatment irrigated daily. After this period, the plants were re-irrigated to run-off and treated as control treatment. The stomatal closure and epinasty observed in response to water stress represented adaptive mechanisms to drought, allowing the plants to regulate water loss more effectively and prevent leaf heating. A substantial reduction in the irrigation water supplied combined with a high frequency of application (T-3 treatment) promoted plant hardening; the plants enduring drought better, due to their greater osmotic adjustment (0.77 MPa), which prevented severe plant dehydration and leaf abscission. Such a preconditioning treatment may be valuable for young apricot plants in the nursery stage in order to improve their subsequent resistance to drought. A 50% reduction in daily irrigation (T-2 treatment) did not significantly affect either gas exchange rates or leaf turgor, which suggests that water should be applied frequently if deficit irrigation is to be implemented.