Weed management in carbon-seeded orchardgrass with preemergence herbicides

摘要

This study was conducted to evaluate orchardgrass grown for seed crop safety and control of diuron resistant annual bluegrass (Poa annua) and roughstalk bluegrass (Poa trivia/is) following applications of preemergence herbicides. 'Persist' orchardgrass was planted in 12 inch rows, 0.25 inches deep with a 1-inch wide band of activated carbon sprayed over the seed rows at 300 lb per acre. Treatments were arranged in a randomized complete block design with four replications. Plots were 8 x 35 ft with 24rows of carbon-seeded orchardgrass and had three rows of diuron resistant Poa annua and three rows of Poa trivia/is planted without carbon in a fallow area in the front of each plot. Applications were made September 24 (Table 1). The study was comprisedof 13 treatments which included a grower standard of diuron plus pronamide (Table 2). The study area received 0.20 inches of rain on September 25. Overhead irrigation was started September 28 with an application of 0.25 inches and continued through cropemergence. Broadleaf weeds were removed with a broadcast application of pyrasulfotole/bromoxynil plus MCPA ester on November 18. The crop was swathed on June 21, and threshed with a small plot combine on July 14. Seed was cleaned with a Clipper Cleanerand yields were quantified (Table 2).