**6. Acknowledgment**

All of the field tests described in this chapter were conducted in the joint research of JIRCAS and CETAPAR-JICA, Yguazu, Alto Parana, Paraguay. I deeply thank Mr. Toshiyuki Horita, Mr. Ken Hoshiba, and Mr. Jorge Bordon for their helpful advice and support. Special thanks are also due Dr. Kazunobu Toriyama and Dr. Ana Kojima for their helpful suggestion and encouragement.
