Project Number: 2070-21630-003-019-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 1, 2022
End Date: Sep 30, 2025
The objective and purpose of this project is to determine if activated carbon seed technologies can be used to protect seeded vegetation from indaziflam applied to control invasive annual grasses.
The project will include two studies intended to evaluate seed enhancement technologies designed to protect seeded species in the context of indaziflam treatment. One study will investigate seeding with activated carbon seed pellets and one will investigate the effectiveness of activated carbon seed coatings with a concurrent application of indaziflam. In the first study, up to four perennial grasses, two shrubs, and two forb species will be seeded at each site. Species will be seeded individually using two seeding treatments, bare seed and activated carbon seed pellets and replicated four times at each site. Treatments will include: 1) bare seed and indaziflam, 2) activated carbon seed pellets and indaziflam, 3) no seed and indaziflam, 4) no seed and no indaziflam, and 5) bare seed and no indaziflam. Each treatment replicate will be 5 x 2 m plot and have l m buffer between it and adjacent plots. Total number of treatment plots will be 1600 (5 treatments X 5 study sites X 8 species X 4 replicates X 2 years = 1600 plots). Seed as bare seed or in activated carbon seed pellets will be seeded in the early fall (prior to annual grass fall emergence) and followed with an application of indaziflam at 73g ai·ha-1 rate. The surfactant Grounded® will be used in conjunction with indaziflam to improve soil adsorption and improve efficacy. The entire experiment will be replicated in two different years to improve the robustness of the test and increase the probability of getting a favorable year for seedling establishment. Activated carbon seed pellets will be made at the ARS-Burns seed enhancement laboratory. In the second study, two species of perennial grasses will be seeded at each site. Seed treatments will be bare seed and seed coated with 0.3 mg of activated carbon. Treatments will be: 1) bare seed and indaziflam, 2) coated seed and indaziflam, 3) no seed and indaziflam, 4) no seed and no indaziflam, and 5) bare seed and no indaziflam. Study design will be the same as the first study, with the exception the study will not start until the second year of the project. Burns-ARS is actively developing seed coatings with a commercial vendor and preliminary grow room studies are necessary to make sure an activated carbon seed coating that has proven effective in the lab is tested in the field. Therefore, the activated seed coatings will not be ready for field testing until the second year of the project. Coating of seeds with activated carbon will be contracted from a commercial seed vendor if current preliminary tests of its effectiveness are satisfactory. For both studies, vegetation sampling to quantify the abundance and cover of seeded species, exotic annual grasses and other plants will occur for two to three years post-seeding. Grazing will be excluded from the study sites for the duration of the study.