The effect of strobilurins on leaf gas exchange, water use efficiency and ABA content in grapevine under field conditions.
Strobilurins are one of the most important classes of agricultural fungicides. In addition to their anti-fungal effect, strobilurins have been reported to produce simultaneous effects in plant physiology. This study investigated whether the use of strobilurin fungicide improved water use efficiency in leaves of grapevines grown under field conditions in a Mediterranean climate in southern Spain. Fungicide was applied three times in the vineyard and measurements of leaf gas exchange, plant water status, abscisic acid concentration in sap ([ABA]), and carbon isotope composition in leaves were performed before and after applications. No clear effect on stomatal conductance, leaf water potential and intrinsic water use efficiency was found after three fungicide applications. ABA concentration was observed to increase after fungicide application on the first day, vanishing three days later. Despite this transient effect, evolution of [ABA] matched well with the evolution of leaf carbon isotope ratio, which can be used as a surrogate for plant water use efficiency. Morning stomatal conductance was negatively correlated to [ABA]. Yield was enhanced in strobilurin treated plants, whereas fruit quality remained unaltered.
Instituto de Recursos Naturales y Agrobiología, IRNAS-CSIC, Apartado 1052, 41080 Sevilla, Spain. adiaz@irnase.csic.es
Antonio
A
Diaz-Espejo
María Victoria
MV
Cuevas
Miquel
M
Ribas-Carbo
Jaume
J
Flexas
Sebastian
S
Martorell
José Enrique
JE
Fernández
D000040:Abscisic Acid / Q000378:metabolism*; D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis; D002734:Chlorophyll / Q000378:metabolism; D055864:Droughts; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D005638:Fruit / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008689:Methacrylates / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D054046:Plant Stomata / Q000187:drug effects; D018526:Plant Transpiration / Q000187:drug effects*; D013030:Spain; D027843:Vitis / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D014867:Water / Q000378:metabolism*
D002247:Carbon Isotopes; D005231:Fatty Acids, Unsaturated; D005659:Fungicides, Industrial; D008689:Methacrylates; D010937:Plant Growth Regulators; D014867:Water; D002734:Chlorophyll; D000040:Abscisic Acid