Title: Use of synthetic ground covers to control weeds in blackberries
Abstract: Weed control in blackberries (Rubus spp.) is a serious problem for organic producers and those who wish to reduce their reliance on herbicides. Three landscape fabrics and one industrial grade white on black plastic were evaluated for weed control in conjuction with newly planted ‘Kiowa’ root cuttings in Feb. 2006 at a site near Monte Alto, Texas (26◦N Lat.). In the no-fabric treatment, weeds were controlled mechanically by hand. The reflectant white plastic and weave weed barriers reduced mid-summer soil temperatures at 10 cm and reduced the magnitude in soil temperature fluctuation. Field plant vigor and plant height measured in 2007 (only) were improved by use of weed barriers. The time required for plot weed removal was shortest for white plastic and longest for bare soil. White plastic improved the average cumulative season yields in both years (6.46 t/ha) compared to yields from plants grown in bare soil (4.58 t/ha), P = 0.003, and also when contrasted against all other weed control methods (P = 0.0003). In 2007, fruit from bare soil plants showed the greatest decline in average fruit size during the picking season. In 2007, fruit from plants grown in bare soil were lowest in soluble solids and sugar:acid ratio compared to fruit from weed barrier treatments. Similar, though non-significant, fruit quality trends existed in 2008 harvested fruit. In both years, fruit grown over white plastic had the highest mean soluble solids concentration (11.3%) compared to bare ground-grown fruit (9.8%). [D. J. Makus (2011). Use of synthetic ground covers to control weeds in blackberries. International Journal of Fruit Science, 11:286–298. DOI: 10.1080/15538362.2011.608300]
KEYWORDS: Rubus spp., weed barriers, white plastic, organic weed control