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

Field experiments were conducted at 18 sites over 4 years in the easte rn and north-eastern wheatbelt of Western Australia where average annu al rainfall is <400 mm, to investigate suitable techniques for the pro duction of high protein (>13%) wheat in an area that traditionally pro duces grain of a much lower average protein percentage. Wilgoyne yield ed 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 culti vars suitable for the Australian Standard White (ASW) grade. Differenc es 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 so wings. Most crops that produced >13% protein followed medic or field p eas. The addition of N fertiliser was seldom required to produce this concentration of protein in crops that followed medic or peas. Crops f ollowing pasture with a low legume content or wheat had lower grain pr otein concentrations. Friable red-brown earth soils in a medic or pea rotation were able to achieve the required grain protein, but other co mbinations were not extensively tested. From these experiments, cultiv ars with inherently small grains due to their propensity to produce hi gh levels of small grain screenings (whole grain through a 2-mm, slott ed sieve) may be less able to increase yields economically by increasi ng kernel numbers per unit area under conditions in Western Australia.