1. Agricultural Research Organization, Institute of Soil, Water and Environmental Sciences; Newe Ya'ar Research Center; Ramat-Yishay Israel
2. Agricultural Research Organization, Institute of Plant Sciences; Newe Ya'ar Research Center; Ramat-Yishay Israel
3. Ort Braude College; Dep. of Biotechnology Engineering; Karmiel Israel
4. Dep. of Microbiology and Plant Pathology, Faculty of Agriculture, Food and Environment; the Hebrew Univ. of Jerusalem; P.O. Box 12 Rehovot 76100 Israel