252 Vandenbroucke et al.: Biological Vegetation Management months up to 3 years. Sprouts that are not dead remain chlorotic and show signs of necrosis. Toxicology and eco-toxicology studies have been conducted by independent laboratories in Canada and the United States for almost 10 years as part of the registration process (PMRA 2002). For the environment, the conclusion states that there is no effect on nontarget species, no effect on conifers, and no hazard to wildlife. Myco-Tech will not increase the natural occurrence of C. purpureum because of the use of mycelium instead of spores (Goulet 1998; Gosselin et al. 1999). Health studies also clearly demon- strate that it is not harmful to human health and is not irritating to skin and eyes. Furthermore, the fungus does not develop at a temperature higher than 37˚C (98.6˚F, body temperature). This paper presents data from a ROW project (Hydro- Québec) to evaluate the use of the biological treatment Myco-Tech for ROW vegetation management of deciduous trees. We propose a new way to visualize raw data of surveys using contour maps and 3D surfaces, allowing rapid evaluation of the efficiency of a biological control. MATERIALS AND METHODS Study Area In 1998, Gosselin (1998) established two adjacent study areas in a randomized complete block design, B1 and B2 for Canadian registration purposes, north of Montréal near Ste- Agathe-des-Monts (46°03′ N, 74°17′ W). The experimental installation was established in Hydro-Québec span #430 of the power line #7044-7047 (735 kV), at the south end of an area chemically treated in 1997. Experimental Installation Each randomized complete block (B1 and B2) of approxi- mately 0.5 ha (1.1 ac) included four replications of two treatments (control: mechanical cutting with brush saw only; treated: mechanical cutting with brush saw + Myco- Tech application) for a total of eight plots per block. In each plot, we installed 10 subplots (radius = 1.13 m [3.7 ft]) on a transect, for a total of 80 subplots per block. Topology, Soil, and Vegetation Composition Elevation in the study area ranged from an estimated 425 to 455 m (1,390 to 1,490 ft). Block B1 faced north, while block B2 faced south. All slopes were less than 10% toward a beaver marsh and a brook. Soil formation was rich and mainly contained a thick humus cover. Block B1 was well- drained, while block B2 was a bit rocky, the soil less rich with hilltop structure. The area is situated in a mixed forest (Canadian Ecozone 4, Canadian Plant Hardiness Zone, Agriculture and Agri-Food Canada). The power line has been maintained through clearing every 4 to 5 years for at least the past 20 years. The last clearing was in 1993. ©2005 International Society of Arboriculture Initial Survey The following deciduous species were found in the study area: Betula alleghaniensis (yellow birch) (2%), Prunus pensylvanica (pin cherry) (8%), Acer rubrum (red maple) (22%), A. saccharum (sugar maple) (18%), A. spicatum (mountain maple) (4%), Populus tremuloides (quaking aspen) (14%), and Salix spp. (willow) (21%). Initial densities of the control areas were 24,000 stems/ha (9,700 stems/ac) in B1 and 53,000 stems/ha (21,500 stems/ac) in B2, while initial densities in the treated areas were 45,000 stems/ha (18,200 stems/ac) in B1 and 52,000 stems/ha (21,000 stems/ac) in B2. CFU/g was applied. Application of 0.5 to 1 mL per stump was done within 5 min of the cut. Treatments Treatments were performed between 17 and 31 August 1998. Myco-Tech paste formulation (Chondrostereum purpureum strain HQ1) at a concentration of 1.0 to 2.8 × 106 Surveys Surveys were done in July 1999, in the last week of June and the first week of July 2000, and in the last week of July 2001 by three independent firms. In each subplot, every stump was surveyed and categorized as dead or living. For each living stump, species, status (dead or alive), height, and diameter (at 15 cm [6 in.] from the ground) of each sprout were surveyed. Data Treatment We developed an approach to visualize the effectiveness of the treatment on a contour map representation using the height of the sprouts. Because survey plots are designed to be representative of the entire experimental area, height of sprouts are positioned on grid coordinates. We made a grid matrix 26 × 27 (696 stems and 6 blanks) for the treated area and a 18 × 19 matrix (342 stems and no blanks) for the control area. Each matrix coordinate represented the measured height of each sprout (blanks are ignored by the software, so they do not interfere in the contour lines calculation). We used the topographic software Surfer version 8.0 (Golden Software, CO) to first compute the grid file and then draw contour maps and their 3D representa- tions, which can be interpreted as ligneous vegetation cover representation. Statistical Analysis Effect of the Myco-Tech treatment on the mean height of highest sprouts was tested by a one-way ANOVA. All P values < 0.05 were considered significant. Statistical analysis was performed with JMP version 5.1. software (SAS Institute, Cary, NC). Confidence intervals were evaluated using α = 0.05.
September 2005
| Title Name |
Pages |
Delete |
Url |
| Empty |
Ai generated response may be inaccurate.
Search Text Block
Page #page_num
#doc_title
Hi $receivername|$receiveremail,
$sendername|$senderemail wrote these comments for you:
$message
$sendername|$senderemail would like for you to view the following digital edition.
Please click on the page below to be directed to the digital edition:
$thumbnail$pagenum
$link$pagenum
Your form submission was a success.
Downloading PDF
Generating your PDF, please wait...
This process might take longer please wait
