Determining the Effect of Biodegradable and Living Mulches on Annual Weeds and and Growth of Newly-planted Blueberry
CSANR Project 150
Status: No-cost extension granted
This project addresses BIOAg Priority Areas on (i) organic approaches to sustainable management of soil quality; (ii) novel approaches to weed management; and, (v) assessment of environmental and social sustainability of an agricultural system (i.e., a living mulch system for highbush blueberry production). The effectiveness of biodegradable mulches (BDM) and living mulches as a means of suppressing annual weeds in other crops is well known. Ground covers and densely-growing living mulches carpet the soil, reducing weed seed germination and restricting weed growth. While living mulches can cause excess competition with crop plants and reduce their growth, this can often be avoided if they are managed properly. Living mulches and BDM have not been tested for use in blueberry, but may offer blueberry producers options for non-chemical annual weed control. Creeping buttercup (Ranunculus arvensis) is a low-growing perennial weed species widespread in western Washington blueberry fields that does not appear to negatively affect blueberry productivity. A second living-mulch species to be tested is sweet woodruff (Galium odoratum), which during testing in newly-planted apple, did not negatively affect apple tree cross-sectional area after two years as a living mulch. These results suggest that sweet woodruff also offers good potential for use as a living mulch in blueberry. A trial is proposed evaluating sawdust mulch, BDM, living mulch species, or organic herbicide applications in newly-planted blueberry in northwestern Washington.