Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: February 4, 2007
Publication Date: June 1, 2007
Citation: Makus, D.J., Jifon, J.L., 2007.Impact of Weed Barriers on Newly Planted Peach Trees, HortScience 42(3):456-457.
Newly planted (Feb. 2005) ‘Sunracer’ and ‘Sunhome’ nectarine and ‘Tropic Snow’ peach (Prunus persica (L.) Batsch) trees were subjected to conventional and four 'organic' weed control methods. Two of the 'organic' methods used weed barriers of white plastic (WP) or landscape fabric (LF). A third consisted of a 10 cm thick mulch of bagasse (Bag). The organic (Org) treatment consisted of weed control by cornmeal gluten, flame, and/or mechanical means. Conventional (Con) weed control was with herbicides. Initial surface lightness (chroma ‘L’ values) of the treatments were WP>Con=Org>Bag>LF (highest to lowest). WP had the highest reflectivity ('Mol/s/m2) into the canopy, then Org=Con> LF=Bag (highest to lowest). By the second season, all treatments were similar in reflectivity except WP (highest). Tree growth after 22 months, based on tree volume and trunk girth, and pruning weights were WP=Bag>>LF=Org=Con (greatest to least). ‘Bag’ had the lowest summer soil temperatures. (at 10 and 30 cm) and lowest variation in mean weely soil temperature in both summer and winter. Decreasing treatment surface temperatures at 1130 hrs (10 Aug 06)were Bag=LF>>Org=Con=WP. Soil moisture (25-100 cm) and 2006 spring flowering were not effected by weed control method. Precocious fall/winter flowering was higher in the WP and Bag control methods. Material and installation costs were WP=LF=Bag>>Org=Con (highest to least). Time required to manually remove 6 weeks of weed growth was Org=Con>LF'Bag'WP (highest to lowest). The most weed biomass generated during a 6 week summer interval was in Con=Org>>LF=Bag=WP. Fall weed biomass was reduced by a factor of 6X and there were season x control method interactions. Grasses were 85% of weed biomass in the summer (Aug) and 75% in the winter (Nov). Bagasse thickness was reduced by 55% after 20 months.