We measured the effects of winter wheat residue, residue placement, nitrogen fertilizer placement, and nitrogen rates on winter wheat growth in greenhouse pot and split root studies under conditions simulating cool-wet spring conditions in the Pacific Northwest. Phytotoxicity to winter wheat plants from decomposing winter wheat residue could not be demonstrated in these studies. When winter wheat straw was mixed with the soil, wheat plant yield decreased significantly, but the decrease was largely overcome by higher rates of N application; hence, in this case, N immobilization during straw decomposition, and not phytotoxicity, appeared to be a primary factor causing yield decreases.

Observation of propagation and prolificacy of silky bent-grass was made in the years 1973-1975 at four stands: in rye and winter wheat grown after various forecrops and in rye and winter wheat monoculture. The propagation and prolificacy of silky bent-grass depended mostly on the conditions existing in the grainfield. The average degree of silky bent-grass propagation was higher in the winter wheat than in the rye field; total propagation was 2.9 and 1.5 and effective propagation [fertile shoots] 2.7 and 1.4 respectively. Silky bent-grass was found to be more fertile in the winter wheat than in the rye field, and the number of grains produced by a plant of this species was, on an average, 4509 in winter wheat and 1461 in rye. The prolificacy of respective silky bent-grass specimens ranged from 74 to 47200 grains from a plant, irrespective of the stand.(Szumilak, G.)

Winter wheat and winter barley were tested for their photochemical and osmotic potentials during the course of one growth cycle in the field. Prolonged winter conditions induced an absolute high in potential net photosynthesis (PN) of winter wheat. Barley exhibited relatively low PN rates, which may explain the inferior frost hardiness of this species. Osmotic potentials (ψπ) in both species were quite similar, followed rather uniform trends and were never extreme. There are doubts, however, whether the ψπ assessments truly reflected the osmotic stress on cell membranes in frost-hardened leaves. Increased deposition of cryoprotective assimilates in wheat as the cause of continued frost hardiness is discussed.

Non-Peer Reviewed | An air-seeder was compared with a Melroe No-Till drill and a conventional double disc press-drill in seeding spring wheat and barley in grain stubble prepared for planting by three methods: spring plowing, spring cultivation, and no-tillage in 1978. Comparative yields showed the air-seeder to be equal to or better than other seeders and that "no-till" was equal to spring plowing or field cultivation. In the fall of 1978 winter wheat and winter rye were seeded in wheat stubble with an air-seeder. Winter wheat planted on adjacent fallow suffered 95 % winter kill but that in the stubble had 70 % survival and yielded 35 bushels/acre. In 1979 the air-seeder was compared with a conventional press drill in planting spring wheat and durum in stubble prepared for planting by spring plowing, field cultivator, and no-till. Yields were greatest from plantings made with the press-drill on spring plowed and/or cultivated land. However, on the no-till treatment the air-seeder yields were about 6 bushels/acre greater than from the press drill. Two years of results suggest the air-seeder is capable of appropriate placement of seed under a wide range of crop residue and soil conditions if land surface is relatively smooth and if depth control is effective.