1 Retired; National Council. Current address Alvear 189. Cordoba. Argentina. nestorberasain51@gmail.com.
2 National Institute Agricultural Technology (INTA). Experimental Rural Agency; Aimogasta. sergiodanteleiva@yahoo.com.ar.
3 National Council of Scientific and Technological Research (CONICET). Physical Institute Enrique Gaviola. Cordoba National University. Faculty of Mathematics; Astronomy; Physics and Computation. jvilchez@famaf.unc.edu.ar.