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Poster: Biology & Disease Mgmt: Cultural Control


Adapting to water insecurity: Co-managing oomycete pathogens and water use using deficit irrigation sensor networks
J. DEL CASTILLO MÚNERA (1), C. Swett (1), B. Belayneh (1), A. Ristvey (2), J. Lea-Cox (1) (1) University of Maryland, U.S.A.; (2) University of Maryland, U.S.A.

Circumglobally, the agricultural sector consumes the highest percentage of available fresh water, and with increases in water insecurity, agricultural demands are becoming unsustainable. Sensor-driven deficit irrigation networks use less water by allowing a mild stress of the crop. The objectives of this study were to evaluate (i) deficit irrigation (DI) as means to reduce root disease in annual and perennial nursery/greenhouse crops; and (ii) effects of DI under various infection scenarios using tomato and P. capsici as pathosystem model, to address grower risks hindering technology adoption. In a two year study, Rhododendron were inoculated with P. cinnamomi and placed under four different irrigation treatments. Mortality incidence after 18 months of inoculation was significant (P = 0.0084), reflecting significantly lower mortality (21%) at 33.5% VWC compared to the 43, and 28 % VWC treatments (29, 51% mortality). Preliminary studies on Poinsettia indicate a higher root rot incidence in the 48% WVC deficit irrigation treatment compared to saturated conditions (60% VWC), but differences were not significant. Studies underway in the model pathosystem are evaluating whether DI strategies can predispose plants to pathogen infection, and use of DI as a tool to prevent latent infection and disease. These studies will be used to develop recommendations for using deficient irrigation to co-manage water use, and disease losses in nursery and greenhouse production