Submitted to: Maine Potato Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 18, 2009
Publication Date: January 22, 2009
Citation: Honeycutt, C.W., Griffin, T.S., Larkin, R.P., Halloran, J.M., Olanya, O.M., He, Z. 2009. IDENTIFYING AND REDUCING CONSTRAINTS TO POTATO PRODUCTIVITY. Maine Potato Conference Abstracts. Page 23. Technical Abstract: Potato yield in Maine has remained relatively constant for over 50 years, despite increased inputs of pesticides, nutrients, and water. Research is needed to identify and reduce the constraints to potato productivity. We evaluated Status Quo, Soil Conserving, Soil Improving, and Disease Suppressive cropping systems under both rainfed and irrigated management for their impacts on plant growth and productivity, soil chemical-physical-biological properties, tuber diseases, soilborne diseases, foliar diseases, economics, and their interactions. The Soil Improving System increased soil carbon, soil nitrogen, and soil aggregate stability, while reducing soil bulk density. In addition, soil at the 6-10 inch depth was much more resistant to penetration in the Status Quo System than in other systems. Plant growth and yield responded to these changes in soil properties. Under rainfed management, highest Leaf Area Index (LAI) was obtained in the Soil Improving System, and lowest LAI was observed in continuous potato. The same relationships were observed under irrigated management; however, differences among cropping systems were much less distinct. Similarly, highest Leaf Area Duration (LAD) was found in the Soil Improving System. These results indicate that management practices focused on improving the soil resulted in potato plant canopies with greater and longer lasting photosynthetic potential. This translated into higher yield, where the Soil Improving System under rainfed management increased potato yield from 23 to 51%. These results show that management practices to improve soils can significantly increase potato yield and can serve as a substitute to supplemental irrigation in the cool, humid Northeast.