Applying Eptc and Seeding Alfalfa (Medicago sativa) Simultaneously

Abstract

Alfalfa (Medicago sativaL. ‘Vernal′) was seeded broadcast or in drill rows spaced 18 cm apart in the same operation that EPTC (S-ethyl dipropylcarbamothioate) was applied. For broadcast seeding, EPTC was applied as herbicide-treated crop seed, as granules mixed with crop seed, or as granules applied with the crop seed, but with the seed and granules carried in separate boxes on the seeder. For drill-row seeding, EPTC was applied between the rows in subsurface lines as a liquid or granular formulation; and within the rows as herbicide-treated seed, as granules mixed with the seed, or as granules carried in a box separate from the seed. Weed control and crop tolerance with the more effective simultaneous applications of EPTC were similar to those with conventional preplant-incorporated applications. To seed alfalfa (either broadcast or in drill rows) and apply EPTC in one operation, the methods wherein untreated seed and a granular formulation of EPTC were applied together but from separate boxes on the seeder were the most practical, because the mechanical components, the seed, and the formulated herbicide are all commercially available.

Cheat (Bromus secalinus) Control with Herbicides Applied to Mature Seeds1

“…Based on results from 1995, additional herbicides were evaluated in 1996 for their ability to reduce cheat emergence when applied directly to the seeds. EPTC was included in 1996 because of evidence that seed-applied EPTC retains its weed control efficacy (Dawson 1987) and that soil-applied EPTC reduced poverty brome (Bromus sterilis L.) 54 to 75% (Pollard et al 1984). Application rates were 0.5, 1, and 1.5ϫ, where 1ϫ is the registered application rate based on the assumptions stated above.…”