Co-Authors:
Seligman, N.G., Dept. of Natural Resources, Agricultural Res. Orguztn., Bet Dagan, Israel
Noy-Meir, I., Dept. of Natural Resources, Agricultural Res. Orguztn., Bet Dagan, Israel
Gutman, M., Dept. of Natural Resources, Agricultural Res. Orguztn., Bet Dagan, Israel