Project Number: 0500-00044-020-02
Project Type: Specific Cooperative Agreement

Start Date: May 01, 2007
End Date: Sep 30, 2011

Objective:
Conduct large-scale (acres) replicated plots in nurseries across the southern United States to demonstrate the technical and economic feasibility of methyl bromide alternatives in the production of loblolly pine seedlings. Specific objectives of these demonstration studies are to evaluate the effects of a number of fumigants that have shown promise in small-scale plots (Table 1) alone and in combination, on loblolly pine production, soilborne fungi, weed control and plant-parasitic nematodes.

Approach:
Nurseries selected for the demonstration sites contain fields that have not been fumigated for over four years. The fields have been in pine production over the past decade and were either planted to a small grain cover crops or disk fallow during the year prior to the study. The demonstration studies are designed as a randomized complete block design with replication by nursery sections or blocks. All treatments will be replicated at least four times at each nursery for each soil treatment. Demonstration sites will be established in 2007 at two Georgia nurseries (Jesup and Glennville, GA). In future years (2008 and beyond), demonstration sites will also be installed in South Carolina, Alabama, Mississippi and Texas (Figure 1) and will include private, state and industrial Nursery Cooperative members. In all study areas, the trials will include two years of seedling production and one year fallow to follow the standard seedling production protocol. Plots for each soil treatment will be three seedbeds wide (16 ft), and plot lengths range from 350 to 500 ft. long. Seedbeds will be prepared at all nurseries by ripping the field with subsoil shanks to break up hardpans and tilled to break up clods. Fumigants tested will be applied according to the label¿s specifications and are outlined in Table 1. The fumigants will be shank injected into the soil to a depth of 15-20 cm and covered with clear high-density polyethylene tarps (broadcast/flat tarp). Tarps will be kept in place for 10 days post-fumigation and then removed. Fumigant treatments will be applied only in the first year of the demonstration at each nursery, of which two seedling crops and two cover crops will be sown.