Location: Horticultural Crops Research2010 Annual Report
1a. Objectives (from AD-416)
1) Evaluate blueberry plant growth, yield, and quality in various certified-organic production systems in two popular fresh-market cultivars; 2) determine the effect of raised beds on soil and plant water status and plant growth, and production; 3) evaluate and continue to develop organic weed management systems in producing blueberries; and 4) develop and evaluate organic fertilizer treatments to optimize plant growth, production, and quality.
1b. Approach (from AD-416)
Treatments being assessed include planting on raised beds or flat ground, various weed management treatments including weed mat, organic fertilization type and rate, and cultivar. We will collect information on not only the effectiveness of the treatments such as weed mat, sawdust and compost mulches and use of vinegar for weed control on flat ground and raised beds and organic fertilizers and how they interact with sawdust mulch and weed mat, but also the cost effectiveness. We will measure plant growth, yield, fruit quality, weed pressure, soil water status, plant water status, plant tissue and soil nutrient concentration, and organic fertilizer availability. We will make observations on any other pest problems and control them to the best of our ability using organically approved methods. We feel that this study will provide growers with very useful information on the long-term impacts and costs of various organic blueberry production systems during fruiting years. Documents Grant with Oregon State University.
3. Progress Report
A 0.4 ha (1 acre) planting of blueberry was established in Oct. 2006 to evaluate the effects of cultivar (Duke and Liberty), bed type (flat versus raised beds), weed management [sawdust mulch and hand-weed control; sawdust+compost mulch with acetic acid, flaming, and hand control used as needed; and weed mat], and type and rate of fertilizer (feathermeal and liquid fish emulsion at 29 and 57 kg.ha-1 N) on plant growth, yield, fruit quality, irrigation requirements, and weed presence. The site was certified organic in 2008. Plants grown on raised beds were larger than those on flat ground but required more irrigation, particularly with weed mat. Weed mat resulted in the fewest weeds while sawdust+compost resulted in the most weeds. In 2008, yield was highest when 29 kg.ha-1 N of fish was applied and when plants were grown on raised beds with weed mat. In year 3 (2009), yield averaged 1.7 kg/plant and was highest when 29 kg.ha-1 of fish or 57 kg.ha-1 of feathermeal was applied and when plants were mulched on raised beds with weed mat or sawdust+compost. Fruit were also firmer at harvest when plants were fertilized with fish rather than feathermeal and when soil was mulched with sawdust compared to weed mat. Weed mat is the least expensive option for weed control so far. Methods of ADODR monitoring included meetings, e-mail, phone calls and site visits.