An example of an IPM study conducted in Georgia. Left photo shows intensive site preparation; herbicides; small-diameter seedlings; compared with IPM treatment (right photo) which involves less intensive site preparation, no herbicides, and large-diameter seedlings.
Both slash pine (Pinus elliottii) seedlings were operationally planted using machines on October 16, 1991. The root-collar diameter (RCD) of the small seedling was 2.5 mm at time of planting and the seedling was planted 2.5 cm deep (i.e. root-collar 2.5 cm below groundline). The large seedling had a 11.5 mm RCD and it was planted 12.5 cm deep.
For the intensive treatment (left photo), weeds were controlled by bedding the soil twice and by applying an application of imazapyr in March, 1992. Weeds on single bedding treatment (right photo) were not treated with a herbicide. Estimated costs of the intensive treatment (left photo) was$410/ha. $200 for the double bedding treatment; $85 for the herbicide treatment; $85 for tree planting; $40 for the 2.5 mm RCD seedlings.
Estimated costs of the IPM treatment (right photo) was$305/ha. $100 for the single bedding treatment; $0 for the herbicide treatment; $85 for tree planting; $120 for the 11.5 mm RCD seedlings (seedling costs are estimated at 3 times that for small diameter seedlings).
Average third-year heights were 181 cm for intensive treatment (left photo) and 218 cm for IPM treatment (right photo). These results suggest that for this site, the IPM treatment (planting large-diameter seedlings with large root mass and no herbicides) may be more cost effective than applying intensive weed control methods to improve the growth of small-diameter seedlings.
For more information contact David South (southdb@auburn.edu) or Bob Mitchell (rmitchel@longleaf.jonesctr.org). Study sponsored by the Auburn University Southern Forest Nursery Management Cooperative. Photo credit (Phil Schrock).
