[1] Univ Bologna, Dept Agr & Food Sci, I-40127 Bologna, Italy
[2] Univ Arizona, Maricopa Agr Ctr, Coll Agr & Life Sci, Sch Plant Sci, Maricopa, AZ 85138 USA
[3] Univ Arizona, Dept Environm Sci, Tucson, AZ 85721 USA
[4] ARS, US Arid Land Agr Res Ctr, USDA, Maricopa, AZ 85138 USA
[5] Danforth Fdn, St Louis, MO 63132 USA