PRODUCTION PRACTICES FOR HIGH-PROTEIN, HARD WHEAT IN WESTERN-AUSTRALIA

Field experiments were conducted at 18 sites over 4 years in the eastern and north-eastern wheatbelt of Western Australia where average annual rainfall is <400 mm, to investigate suitable techniques for the production of high protein (>13%) wheat in an area that traditionally produces grain of a much lower average protein percentage. Wilgoyne yielded as well as, or better than, any of the cultivars accepted into the Special Hard (SH) grade in Western Australia but 5-10% less than cultivars suitable for the Australian Standard White (ASW) grade. Differences between cultivars were greatest at the optimum sowing time in late May. Lower yields in early May were attributed to water stress during early growth or to frost damage during grain filling. The addition of nitrogen (N) fertiliser to crops sown after 1 June was less effective in increasing grain yield and grain protein than N added to earlier sowings. Most crops that produced >13% protein followed medic or field peas. The addition of N fertiliser was seldom required to produce this concentration of protein in crops that followed medic or peas. Crops following pasture with a low legume content or wheat had lower grain protein concentrations. Friable red-brown earth soils in a medic or pea rotation were able to achieve the required grain protein, but other combinations were not extensively tested. From these experiments, cultivars with inherently small grains due to their propensity to produce high levels of small grain screenings (whole grain through a 2-mm, slotted sieve) may be less able to increase yields economically by increasing kernel numbers per unit area under conditions in Western Australia.