William Wright Kirk, Associate Professor

 Contact information:

Education:

General areas of expertise:

Overview of current program:

Crop pathogens cause severe reductions in the yield and quality of potato and field crops across the US. Many disease protection strategies depend upon high level inputs of agrochemicals, for example in potato late blight protection. However, the economics of crop protection and the threat of removal of inexpensive, high environmental risk products and replacement with expensive low risk products erode the profitability of the industry. Replacement products, may, however reduce criticism from environmental groups seeking to reduce reliance on pesticides but limit broad spectrum disease control in potatoes and field crops. In order to maximize fungicide performance two main approaches may be followed; the use of cultivars with better tolerance to disease and prediction of environmental conditions that influence disease development. Both approaches enable growers to apply specific fungicides at appropriate rates and frequencies in response to disease pressure in their crops. There are currently several types of fungicide applied routinely for prevention of potato and field crop diseases in Michigan. Other fungicides are available that have specific activity for control of specific pathogen stages that could be used when conditions are after infection has occurred. In order to effectively advise growers on the appropriate disease control strategy it is necessary to have information based on a knowledge of fungicide efficacy, foliar development, varietal susceptibility to a particular disease, intended market, past and current weather records and future weather predictions for specific areas.

Michigan can minimize the impact of potato and field crop diseases, provided knowledge of the disease risk is well communicated and the current information base is implemented as a strategy to prevent disease establishment in Michigan.

The program concentrates on major problems in Michigan including potato foliar diseases (late and early blight), potato seed and soil borne diseases (Rhizoctonia stem canker, common scab, Fusarium dry rot, Oomycete disease of tubers); sugarbeet Rhizoctonia crown and root rot and Cercosopra leaf spot; Fusarium head blight in wheat; and seed and foliar diseases of perennial plants such as delphinium, daylily, lupine and gladiolus. A major emphasis of the program is to establish predictive models in co-operation with Dr. J. Andresen (Geography) for various potato and field crop diseases in order to apply timely and appropriate control measures. A nationally recognized potato late blight breeding program has already been established in co-operation with Dr. Douches (Crops and Soil Science). The beneficiaries of this program are the growers, processors and consumers of Michigan potato and field crop products. Our overall aim is to reduce production costs through an understanding of the interactions of the pathogen with its host and environment.

Publications:

Douches, D.S., J. Coombs, R. Hammerschmidt, W.W. Kirk, C. Long, S. Snapp, B. Kudwa, D. Flannery and T. Bourgoin. 2006. Beacon Chipper: A round white chip processing variety. Amer. J. Potato Res. 83(3): 241-248.

Kirk, W. W., A. B. da Rocha, Hollosy, S. I., and R. Hammerschmidt. 2006. Effect of soil salinity on internal browning of potato tuber tissue in two soil types. Amer. J. Potato Res. 83(3): 223-232.

Kirk, W.W., F. M. Abu-El Samen, J.B. Muhinyuza, R. Hammerschmidt, D.S. Douches, C. A. Thill, H. Groza and A. L. Thompson. 2005. Evaluation of potato late blight management utilizing host plant resistance and reduced rates and frequencies of fungicide applications. Crop Protection 24: 961 - 970

Baker, K.M., W.W. Kirk, J.M. Stein and J.A. Andresen. 2005. Climatic trends and potato late blight risk in the Upper Great Lakes region. HortTechnology 15(3):510-518.

Rubio-Covarrubias O.A., D.S. Douches, R. Hammerschmidt, A. daRocha and W.W. Kirk. 2005. Effect of temperature and photoperiod on symptoms associated with resistance to Phytophthora infestans after leaf penetration in susceptible and resistant potato cultivars. Amer. J. Potato Res. 82:153 - 160.

Douches, D.S., J. Coombs, K. Felcher and W.W. Kirk. 2004. Field evaluation of foliar resistance to Phytophthora infestans in potato. Amer. J. Potato Res. 81:443-448.

Stein, J.M. and W.W. Kirk. 2004. Development of resistance in Phytophthora infestans isolates from several genetic backgrounds to Dimethomorph. Plant Disease 88:930-934.

Douches, D.S., J. Coombs, K. Jastrzebski, R. Hammerschmidt, W.W. Kirk, C. Long, R.W. Chase, and S. Snapp. 2003. Boulder: A round white multipurpose potato variety. Amer. J. Potato Res. 80:345-352.

Kirk.,W.W. 2003. Tolerance of mycelium of different genotypes of Phytophthora infestans to freezing temperatures for extended periods. Phytopathology 93:1400-1406.

Stein, J.M. and W.W. Kirk. 2003. Variations in the sensitivity of Phytophthora infestans isolates from several genetic backgrounds to Dimethomorph. Plant Disease 87:1283-1289.