1990) POTATO MANAGEMENT SYMPOSIUM PAPERS

Symposium Summary and Discussion 67

Dr. David Curwen University of Wisconsin

Hancock, WI

The objective of the symposium was to discuss some of the more crit- ical interactions (interrelationships) between various components of pota- to production. An understanding of such interactions is essential for de- veloping an integrated system approach to potato crop management. An integrated approach is needed because the crop management decision mak- ing process has become more complex.

To the degree that several critical, component interactions were detailed and discussed, the symposium met its objective. The foregoing papers in- dicated, an excellent job by symposium participants in describing potato responses to interacting effects of production components, especially the interaction of fertility with irrigation. For example, it was shown that yield and tuber quality could be reduced by interactions between nitrogen and irrigation management. Tuber quality, as reflected by bruising, was also affected by interactions between fertility, irrigation and harvester opera- tion. Additionally, the severity of bruising was influenced by interactions with soil temperature. The incidence of early blight and Verticillium wilt was related to interactions between fertility (especially nitrogen) and irri- gation. Mechanisms for such responses may have been due to synergistic or antagonistic effects of component interactions. Or such interactions may have resulted in altered host susceptibility to or predisposing plants to both biotic and abiotic factors. Symposium participants clearly showed that in- teractions between production components are complex. One example, not all cultivars respond in the same way to a given interaction. They also iden- tified knowledge gaps which suggested that much research still needs to be done to further our understanding of component interactions.

Increased knowledge of component interactions has important prac- tical applications. Greater knowledge can lead to more efficient produc- tion and thus, optimization of economic returns. Greater knowledge of in- teractions is important to maintaining environmental integrity, particularly of soil/water resources. There is increasing concern over the nitrate/pesti- cide contamination of groundwater and soil loss through water/wind ero- sion. Maintaining environmental integrity is a problem that needs to be addressed. Increased understanding of component interactions is essen- tial to attenuation of that problem.

The symposium clearly provided a challenge . . . to use knowledge of component interactions in integrating potato crop production. In de-

68 AMERICAN POTATO JOURNAL (Vol. 67

veloping an integrated system approach, interactions between irrigation and fertility (particularly nitrogen fertility) will play a significant role. Be- cause of the complexity of component interactions, the integrated system approach will depend upon computers and appropriate software packages. An example is the PCM - Potato Crop Management software program de- veloped and released by the University of Wisconsin. While not a fully in- tegrated program, its modular design readily allows incorporation of com- ponent interactions. Successful integration of potato crop management will also require an interdisciplinary, team effort.

Successfully meeting the challenge . . . integrating potato crop man- agement . . . is the key to enhancing potato productivity (yield/quality), to increasing production efficiency, to optimizing economic returns and to maintaining environmental integrity. It is both a research and exten- sion challenge.