* Corresponding author. Tel.: +91 9335303793; fax: +91 522 2480738.
E-mail address: sudhirshukla151@yahoo.com (S.K. Shukla).
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/agwat
0378-3774/$ – see front matter # 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.agwat.2007.02.008