Effect of sowing depth, seed dressings, a press wheel, cultivars and trifluralin on the establishment of barley

Abstract

A factorial field experiment was carried out to determine the effects on barley establishment of 3 depths of sowing (45, 65 and 85 mm), 2 fungicide seed dressings (carboxin and triadimefon), a press wheel compared with a chain harrow, 2 cultivars (Prior and Grimmett), and the pre-emergence herbicide trifluralin incorporated prior to sowing. A laboratory experiment was also conducted to determine the effect of the 2 seed dressings on the coleoptile length of Prior and Grimmett at 20¦C. The press wheel increased seedling establishment from 74 to 88% at a sowing depth of 45 mm, but from 55 to 89% at 85 mm. Carboxin seed dressing increased coleoptile length by 10-17 mm and triadimefon reduced it by 13-1 8 mm. Carboxin also gave better establishment than triadimefon when seed was sown deep. The cultivar Grimmett had shorter coleoptiles than Prior but slightly faster seedling emergence. The shortstatured cultivars now being bred for lodging resistance may also have short coleoptiles and hence poor establishment from deep sowings. The use of a press wheel improved establishment from a depth of 85 mm on a black earth soil. Incorporation of the herbicide trifluralin in the black earth soil 1 week before sowing did not affect establishment. A general lack of significant interactions meant that the main effects were usually additive, establishment increasing from 38% in the worst treatment (85 mm, triadimefon, chain harrow, Grimmett, no trifluralin) to 98% in the best (65 mm, carboxin, press wheel, Grimmett, trifluralin).