Maximum Yield – Minimum Cost: Developing Plant-Based Measures to Determine Irrigation

Needs of Orange Trees

Emily Nguyen Wieber

Committee Members:

Dr. H. Jochen Schenk, Dr. Darren Sandquist, and Dr. Joel Abraham 1

Background

• CA’s citrus crops

→ Brings $ 1.3 billion yr-1(Cooley et al. 2009)

→ Uses 80% of water supplies(Cooley et al. 2009)

→ Citrus growers often over-irrigate(Cooley et al. 2009)

→ Water becomes scare

• How to irrigate effectively?

→ Regulated deficit irrigation (RDI or DI) during the early fruit growth(Golhamer and

Salinas 2000 ) and fruit ripening period(Aquado et al. 2012, Ballester et al. 2011, Garcia-Tejero et al.2011,Ginestar et al. 1996)

→ Uses plant-based measures(Aquado et al. 2012)

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3

Irrigation Based on Crop Evapotranspiration (ETc)

Allen et al. 1998

Three Plant-Based Measures: Overview

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Plant-Based Measures Pros & Cons

Stem water potential (Ψstem)is measured with

Pressure Chamber(Scholander et al. 1965)

+ Direct measure of water need- Destructive, labor intensive, & discrete

Sap flow (SF)is measured with

Sap Flow Sensor(Smith and Allen 1996)

+ Continuous- Indirect measure of water need

Max. daily trunk shrinkage (MDS)is measured with

Point dendrometer(Steppe et al. 2006 andDe Schepper and Steppe 2010)

+ Continuous- Indirect measure of water need

Measure stem with Pressure Chamber

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Taiz and Zeiger 2010

Goldhammer and Salinas 2000

Measure SF Volume with SF Sensor

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ICT International

Ortuno et al. 2006

Measure MDS with Point Dendrometer

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Daily stem diameter variation

Cochard et al. 2001 Ortuno et al. 2006

Study Species & Field Site

• Navel Orange Trees

→ Citrus sinensis (L.) Osbeck

→ Root stocks, Carrizo citrange

→ 4 years old

• Study Site & Irrigation treatments

→ UC Riverside’s Agricultural Experiment Station

→ DI will applied during early fruit growth and the fruit ripening periods ( ~ June to July & Oct. to Dec. in 2013 and 2014 )

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Field Site

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Irrigation Regulations

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Legend: Green: 1.0 ETc (control)Orange: DI1,25% ETc 06/01 – 07/15 100% ETc rest of the yrPurple: DI2,25% ETc 06/01 – 07/5, 75% ETc 10/16 – 12/15100% ETc rest of the year

: Tree will be instrumented: Irrigation timer and/or

pressure regulator

Measurable Variables

• Plant-Based Measures→ Ψstem, SF, & MDS

→ The most sensitive measure will be use for 2nd year irrigation scheduling

• Yield→ Total fruit yield per tree (kg tree-1)

→ Ratio of total fruit yield to total amount of irrigated water

→ Fruit size, juice content, pH

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Predicted results

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ψstem: DI2 most negative; more negative in summer than in winter

SF: DI2 lowest; increase in summer

MDS: DI2 highest; increase in early summer

Predicted Results (Cont.)

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0.00

0.50

1.00

1.50

2.00

15-Jun 15-Jul 14-Aug 13-Sep 13-Oct 12-Nov 12-DecS

ign

al

Inte

nsi

ty

Ψstem SF MDS

Signal intensity: SF > Ψstem and MDS

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Predicted Results (Cont.)

Fruit yield & quality: DI2 = control > DI1

Conclusions based on Predicted Results

• Plant-Based Measures

→ SF is expected to have highest signal intensity, and most sensitive indirect measure of water need

→ Ψstem and MDS are expected to have equally lower signal intensities

• Fruit yield

→ DI2 is expected to save more water but yield the same as the control

→ DI2 is expected to save more water & yield more than DI1

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Significance

• Recommendation to growers for improving irrigation scheduling

• This could lead to ~ 19% water savings yr-1

• Increased sustainability for CA’s citrus industry

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References Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration-Guidelines for computing crop water requirements-FAO Irrigation and drainage paper 56. FAO, Rome, 300, 6541.

Aquado, A., Frias, J., Garcia-Tejero, I., Romero, F., Muriel, J., and Capote, N. (2012). Towards the improvements of fruit-quality parameters in citrus under deficit irrigation strategies. International Scholarly Research Network, 2012. 1-9.

Ballester, C., Castel, J., Intrigliolo, D. S., & Castel, J. R. (2011). Response of Clementina de Nules citrus trees to summer deficit irrigation. Yield components and fruit composition. Agricultural Water Management, 98(6), 1027-1932.

Blake, C. (2008). California citrus industry braces for impact of Asian citrus psyllid. Western Farm Press. Retried on November 15, 2012 from http://westernfarmpress.com/orchard-crops/california-citrus-industry-braces-impact-asian-citrus-psyllid

California Economy. Retrieved on November 15, 2012 from http://www.netstate.com/economy/ca_economy.htm

Cochard, H., S. Forestier, and T. Ameglio. 2001. A new validation of the Scholander pressure chamber technique based on stem diameter variations. Journal of Experimental Botany 52, 1361-1365.

Cooley, H., Christian-Smith, J., & Gleick, P. (2009). Sustaining California agriculture in an uncertain future. Pacific Institute, July Report, 1-81.

De Schepper, V. and K. Steppe. 2010. Development and verification of a water and sugar transport model using measured stem diameter variations. Journal of Experimental Botany 61, 2083-2099.

Dinar, A. (2012, October). The water situation in California and the citrus industry. Power point presentation presented at the citrus conference, Porterville, Ca.

Garcia-Tejero, I., Hugo Duran-Zuazo, V., Luis Muriel-Fernandez, J., Martinez-Garcia, G., & Antonio Jimenez-Bocanegra, J. (2011). Benefits of low-frequency irrigation in citrus orchards. Agronomy for Sustainable Development, 31(4), 779-791.

Garcia-Tejero, I. F., Duran-Zuazo, V. H., Arriaga, J., & Muriel-Fernandez, J. L. (2012). Relationships between trunk- and fruit-diameter growths under deficit-irrigation programmes in orange trees. Scientia Horticulturae, 133, 64-71.

Garcia-Tejero, I. F., Duran-Zuazo, V. H., Muriel-Fernandez, J. L., & Jimenez-Bocanegra, J. A. (2011). Linking canopy temperature and trunk diameter fluctuations with other physiological water status tools for water stress management in citrus orchards. Functional Plant Biology, 38(2), 106-117.

Ginestar, C. and Castel, J.R., 1996. Responses of young clementine citrus trees to water stress during different phenological periods. Journal of Horticultural Science, 71(4): 551-559.

Goldhamer D.A. & Salinas M. 2000. Evaluation of regulated deficit irrigation on mature orange trees grown under high evaporative demand. In: Proceedings of the International Society of Citriculture IX Congress, Orlando, FL, pp. 227-231.

Grismer, M.E., Snyder, R.L., & Faber, B.A. (2000). Avocado and citrus orchards along the coast may use less water. California Agriculture, 25-29.

O’Brien, J. M. (2012, October 21). The vine nerds. Wired Science. Retrieved November 15, 2012, from http://www.wired.com/wiredscience/2012/10/mf-fruition-sciences-winemakers/all/

Ortuno, M. F., Alarcon, J. J., Nicolas, E., & Torrecillas, A. (2004). Interpreting trunk diameter changes in young lemon trees under deficit irrigation. Plant Science, 167(2), 275-280.

Ortuno, M. F., Garcia-Orellana, Y., Conejero, W., Ruiz-Sanchez, M. C., Alarcon, J. J., & Torrecillas, A. (2006). Stem and leaf water potentials, gas exchange, sap flow, and trunk diameter fluctuations for detecting water stress in lemon trees. Trees-Structure and Function, 20(1), 1-8.

Scholander, P. F., H. T. Hammel, E. D. Bradstreet, and E. A. Hemmingsen. 1965. Sap pressure in vascular plants. Science 148, 339-346.

Smith, D. M. and S. J. Allen. 1996. Measurement of sap flow in plant stems. Journal of Experimental Botany 47, 1833-1844.

Spiegel-Roy, P, & Goldschimdt, E. E. (1996). The biology of citrus. Cambridge: Cambridge University Press.

Taiz, L., Zeiger, E. (2010). Plant Physiology (5th ed.). Sunderland, Massachusetts: Sinauer Associates Inc.

Steppe, K., D. J. W. De Pauw, R. Lemeur, and P. A. Vanrolleghem. 2006. A mathematical model linking tree sap flow dynamics to daily stem diameter fluctuations and radial stem growth. Tree Physiology 26, 257-273.

Steppe, K., De Pauw, D. J. W., & Lemeur, R. (2008). A step towards new irrigation scheduling strategies using plant-based measurements and mathematical modelling. Irrigation Science, 26(6), 505-517.

Takele, E., Menge, J. A., Pehrson, J. E., Meyer, J. L., Coggins, C. W., Arpaia, M. L., et al. (1993). ECONOMIC-ANALYSIS OF INTEGRATED CROP MANAGEMENT-PRACTICES OF NAVEL ORANGES. Journal of the American Society for Horticultural Science, 118(6), 910-915.

Takele, E., Meyer, J. L., Arpaia, M. L., Stottlemyer, D. E., & Witney, G. W. (1996). Economic analysis of irrigation and fertilization management of avocados. Hortscience, 31(1), 156-159.

USDA 2008. Farm and ranch irrigation survey. United States Department of Agriculture, Washington, D.C. Retrieved on November 15, 2012, from http://www.agcensus.usda.gov/Publications/2007/Online_Highlights/Farm_and_Ranch_Irrigation_Survey/index.asp 17

Acknowledgements

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• UCR’s Agricultural Experiment Station

→ Dr. Peggy Lemaux

→ Susie Lee

→ UCR Staff (Robert)

• Cal State Fullerton

→ Ed Read

→ Miguel Macias

• Family

→ Bob Wieber

Questions and Commences

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