2011 Annual Report 1a.Objectives (from AD-416) The objectives of this study are to develop best irrigation and fertigation practices and weed management systems in organic ‘Marion’ and ‘Black Diamond’ machine-harvested for processing. In addition to developing a feasibility study and cost analysis for organic trailing blackberry production, we will evaluate the impact of post-harvest irrigation on plant growth, yield, and quality, ascertain the incidence of cane disease, and determine the impact of weed presence on productivity. 1b.Approach (from AD-416) A new planting will be established at the North Willamette Research and Extension Center on land in “transition”. Planting will be in spring 2010 such that the first fruit harvest in 2011 will be organic (certified by Oregon Tilth). Treatments include: cultivar (‘Marion’ and ‘Black Diamond’); irrigation (post-harvest and no post-harvest irrigation); weed management (weed mat, hand-hoed, and non-weeded); and primocane training date (August and February). 3.Progress Report The objectives of this study are to develop best irrigation and fertigation practices and weed management systems in organic ‘Marion’ and ‘Black Diamond’ machine-harvested for processing. Specifically, we will. 1)develop weed management systems and determine the impact of in-row weed presence on plant growth, machine harvest efficiency, and fruit quality;. 2)study impact of machine-harvest on ‘Marion’ and ‘Black Diamond’ yield, quality, and cost of production;. 3)evaluate the incidence of cane disease (purple blotch and septoria);. 4)develop best fertigation practices for application of organic fertilizers; and. 5)determine the water requirements of ‘Marion’ and ‘Black Diamond’ blackberry and identify the effects of post-harvest irrigation on primocane growth, bud set, weed development, incidence of frost and disease damage, and flower and fruit production in each cultivar. The planting is well established, and data collection on the treatment effects on growth and nutrient allocation and plant and soil nutrient status have started. We are collecting data on plant and soil water status and are seeing treatment effects and are adjusting irrigation levels accordingly. We were not able to harvest fruit in 2011, as planned, due to insufficient growth. Based on input from our advisory committee, we cut off the primocanes in February 2011 to have the planting in an “off” year to better match industry practice. Methods of project monitoring included meetings, e-mail, and phone calls.