Developing Damage and Economic Thresholds for Foliar Disease Management in Perennial Plantings of Strawberry 2002
Project Leader(s): William W. Turechek and Marvin P. Pritts
Type of grant: Monitoring, forecasting, and economic thresholds
Project location(s): Findings can be applied across the Northeast
Abstract: Leaf spot, leaf blight, and leaf scorch are foliar diseases of strawberry commonly found in perennial plantings throughout North America. These diseases are suspected to adversely affect yield, winter hardiness, and the overall production life of a planting. A three year study was implemented to determine to what extent these diseases impact yield and the production life of a planting, and to define when it is economically feasible to manage them. The first year of the study focused on: 1) Gathering baseline yield data in established plots in Ithaca, NY; 2) Creating a disease gradient across these plots so that we may effectively study how disease impacts yield over the production life of the planting; 3) Establishing a _ acre strawberry planting in Geneva, NY with varieties that are differentially susceptible to the diseases under study; and 4) Developing and refining experimental procedures to look at the effects of disease under experimental conditions. From the above, we were able to establish that yield across all experimental plots located in Ithaca was statistically identical this year (as we expected). Therefore, our hypothesis is that any future reduction in yield would be directly correlated with the disease gradient, i.e., the lowest yielding plots would have the highest level of disease. For greenhouse/laboratory-based experiments, we had to work through several glitches in the experimental procedures before we were able to make any headway. We started work with leaf scorch (we will look closely at the other diseases this winter). Preliminary results showed that photosynthesis declined rapidly and approached zero as leaf scorch severity increased. This implies that moderate to heavily infected leaves are contributing very little to the development of the plant and would presumably have a negative impact on yield. Identifying these types of relationships for the other diseases under study will allow us to make formal recommendations as to when management is economically feasible. The second year of the study will bring to light much about these diseases and their affect on production.