DEVELOPMENT AND USE OF A BARLEY CROP SIMULATION-MODEL TO EVALUATE PRODUCTION MANAGEMENT STRATEGIES IN NORTH-EASTERN AUSTRALIA

A study was undertaken to identify improved management strategies for barley (Hordeum vulgare L.), particularly in relation to time of plant ing, location, and frost risk in the variable climate of north-eastern Australia. To achieve this objective, a crop growth simulation model (QBAR) was constructed to integrate the understanding, gained from fie ld experiments, of the dynamics of crop growth as influenced by soil m oisture and environmental variables. QBAR simulates the growth and yie ld potential of barley grown under optimal nutrient supply, in the abs ence of pests, diseases, and weeds. Genotypic variables have been dete rmined for 4 cultivars commonly grown in the northern cereal productio n areas. Simulations were conducted using long-term weather data to ge nerate the probabilistic yield outcome of cv. Grimmet for a range of t imes of planting at 10 locations in the north-eastern Australian grain belt. The study indicated that the common planting times used by grow ers could be too late under certain circumstances to gain full yield p otential. Further applications of QBAR to generating information suita ble for crop management decision support packages and crop yield forec asting are discussed.