TY - JOUR
T1 - Long-term growth, water consumption and yield of date palm as a function of salinity
AU - Tripler, Effi
AU - Shani, Uri
AU - Mualem, Yechezkel
AU - Ben-Gal, Alon
PY - 2011/11
Y1 - 2011/11
N2 - Actual measurements of water uptake and use, and the effect of water quality considerations on evapotranspiration (ET), are indispensable for understanding root zone processes and for the development of predictive plant growth models. The driving hypothesis of this research was that root zone stress response mechanisms in perennial fruit tree crops is dynamic and dependent on tree maturity and reproductive capability. This was tested by investigating long-term ET, biomass production and fruit yield in date palms (Phoenix dactylifera L., cv. Medjool) under conditions of salinity. Elevated salinity levels in the soil solution were maintained for 6 years in large weighing-drainage lysimeters by irrigation with water having electrical conductivity (EC) of 1.8, 4, 8 and 12dSm-1. Salinity acted dynamically with a long-term consequence of increasing relative negative response to water consumption and plant growth that may be explained either as an accumulated effect or increasing sensitivity. Sensitivity to salinity stabilized at the highest measured levels after the trees matured and began producing fruit. Date palms were found to be much less tolerant to salinity than expected based on previous literature. Trees irrigated with low salinity (EC=1.8dSm-1) water were almost twice the size (based on ET and growth rates) than trees irrigated with EC=4dSm-1 water after 5 years. Fruit production of the larger trees was 35-50% greater than for the smaller, salt affected, trees. Long term irrigation with very high EC of irrigation water (8 and 12dSm-1) was found to be commercially impractical as growth and yield were severely reduced. The results raise questions regarding the nature of mechanisms for salinity tolerance in date palms, indicate incentives to irrigate dates with higher rather than lower quality water, and present a particular challenge for modelers to correctly choose salinity response functions for dates as well as other perennial crops.
AB - Actual measurements of water uptake and use, and the effect of water quality considerations on evapotranspiration (ET), are indispensable for understanding root zone processes and for the development of predictive plant growth models. The driving hypothesis of this research was that root zone stress response mechanisms in perennial fruit tree crops is dynamic and dependent on tree maturity and reproductive capability. This was tested by investigating long-term ET, biomass production and fruit yield in date palms (Phoenix dactylifera L., cv. Medjool) under conditions of salinity. Elevated salinity levels in the soil solution were maintained for 6 years in large weighing-drainage lysimeters by irrigation with water having electrical conductivity (EC) of 1.8, 4, 8 and 12dSm-1. Salinity acted dynamically with a long-term consequence of increasing relative negative response to water consumption and plant growth that may be explained either as an accumulated effect or increasing sensitivity. Sensitivity to salinity stabilized at the highest measured levels after the trees matured and began producing fruit. Date palms were found to be much less tolerant to salinity than expected based on previous literature. Trees irrigated with low salinity (EC=1.8dSm-1) water were almost twice the size (based on ET and growth rates) than trees irrigated with EC=4dSm-1 water after 5 years. Fruit production of the larger trees was 35-50% greater than for the smaller, salt affected, trees. Long term irrigation with very high EC of irrigation water (8 and 12dSm-1) was found to be commercially impractical as growth and yield were severely reduced. The results raise questions regarding the nature of mechanisms for salinity tolerance in date palms, indicate incentives to irrigate dates with higher rather than lower quality water, and present a particular challenge for modelers to correctly choose salinity response functions for dates as well as other perennial crops.
KW - Evapotranspiration
KW - Long-term response
KW - Salinity
KW - Yield
UR - http://www.scopus.com/inward/record.url?scp=80052736208&partnerID=8YFLogxK
U2 - 10.1016/j.agwat.2011.06.010
DO - 10.1016/j.agwat.2011.06.010
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AN - SCOPUS:80052736208
SN - 0378-3774
VL - 99
SP - 128
EP - 134
JO - Agricultural Water Management
JF - Agricultural Water Management
IS - 1
ER -