Crop yield response to water - Cra

In applying RDI strategies an important factor is fruit load, and to manage the degree of plantwater stress according to the number of fruit per tree. As has been discussed previously, thefruit load per se has a strong influence on the final size of the fruit (Naor et al., 1999). If fruitnumbers are very high and water is limited, there is a risk that imposing an RDI regime wouldinduce a fruit size reduction. In that case it would be better to reduce fruit load by thinningto achieve the fruit size distribution of the crop that economically provides the highest netprofit to the grower. If fruit load is low, RDI may even increase fruit size above that of fullirrigation and will decrease vegetative growth and summer pruning costs. With medium fruitloads, optimal RDI that reduce ET c by 15-20 percent would not have a negative impact on yieldin most cases.REFERENCESArbeloa, A. & Herrero, M. 1991. Development of the ovular structures in peach (Prunus persica (L.) Batsch). NewPhytologist 118: 527–534.Ayars, J.E., Johnson, R.S., Phene, C.J., Trout, T.J., Clark, D.A. & Mead, R.M. 2003. Water use by drip-irrigated lateseasonpeaches. Irrigation Science 22:187-194.Chalmers, D.J., Mitchell, P.D. & Van Heek, L. 1981. Control of peach tree growth and productivity by regulatedwater supply, tree density and summer pruning. Journal of the American Society for Horticultural Science106:307-312.DeJong, T.M., Doyle, J.F., & Day, K.R. 1987. Seasonal patterns of reproductive and vegetative sink activity in earlyand late maturing peach (Prunus persica) cultivars. Physiologia Plantarum 71:83-88.FAO. 2011. FAOSTAT online database, available at link http://faostat.fao.org/. Accessed on December 2011.Gelly, M., Recasens, I., Mata, M., Arbones, A., Rufat, J., Girona, J. & Marsal, J. 2003. Effects of water deficitduring stage II of peach fruit development and postharvest on fruit quality and ethylene production. Journal ofHorticultural Science & Biotechnology 78:324-330.Gelly, M., Recasens, I., Girona, J., Mata, M., Arbones, A., Rufat, J. & Marsal, J. 2004. Effects of stage II andpostharvest deficit irrigation peach quality during maturation and after cold storage. Journal of the Science ofFood and Agriculture 84:561-568.Girona, J., Mata, M., Fereres, E., Goldhamer, D.A. & Cohen, M. 2002. Evapotranspiration and soil wáter dynamicsof peach tres under wáter déficits. Agricultural Water Management 54:107-122.Girona, J., Mata, M., Arbones, A., Alegre, S., Rufat, J. & Marsal, J. 2003. Peach tree response to single and combinedregulated deficit irrigation regimes under shallow soils. Journal of the American Society for Horticultural Science128:432-440.Girona, J., Marsal, J., Mata, J., Arbones, J. & DeJong, T.M. 2004. A comparison of the combined effect of waterstress and crop load on fruit growth during different phenological stages in young peach trees. Journal ofHorticultural Science & Biotechnology 79:308-315.Girona, J., Gelly, M., Mata, M., Arbones, A., Rufat, J. & Marsal, J. 2005. Peach tree response to single and combineddeficit irrigation regimes in deep soils. Agricultural Water Management 72:97-108.Goldhamer, D.A., Fereres, E., Mata, M., Girona, J. & Cohen, M. 1999. Sensitivity of continuous and discrete plantand soil water status monitoring in peach trees subjected to deficit irrigation. Journal of the American Societyfor Horticultural Science 124:437-444.Goodwin, I. & Bruce, R. 2011. Postharvest deficit irrigation decreases subsequent fruit number in T204 peach. ActaHorticulturae 889: 205-212.Handley, D.F. & Johnson, R.S. 2000. Late summer irrigation of water-stressed peach trees reduces fruit doublesand deep sutures. Horticultural Science, 35(4):771.Johnson, R.S. & Handley, D.F. 1989. Thinning response of early, mid-, and late-season peaches. Journal of theAmerican Society for Horticultural Science, 114(6):5-12.Johnson, R.S., Handley, D.F. & DeJong, T.M. 1992. Long-term response of early maturing peach trees to postharvestwater deficits. Journal of the American Society for Horticultural Science, 117(6):881-886.Johnson, R.S. & Handley, D.F. 2000. Using water stress to control vegetative growth and productivity of temperatefruit trees. Horticultural Science, 35(6):1048-1050.peach 405