Diagnostic agronomy, Dubbo, 18 th October 2010 Allan Mayfield, Clare, SA

Nutrition P - P audits, plant tests, P rate test strips N - Soil N, plant NIR & sap N, NDVI (GreenSeeker), look at it!, Baldock model, Yield Prophet, experience Other nutrients – visual symptoms, plant tests (diagnosis & monitoring)

Nutrition management in zones

Soil water Yield Prophet Sensors – eg Sentek Metal push probes

Using zones to improve soil water assessments

Weeds Acceptable weed control is typically well below the economic thresholds for yield loss For herbicide resistance – Quick-Test (green plants), seed tests, herbicide test strips

Weed control according to zones Ryegrass % cover /canola % cover

Diseases Pre-emptive for root diseases – Predicta B test, observations in previous crop(s) For foliar diseases – when symptoms or pre-emptive. Fungicide use now very common. Varietal resistance can be a major factor in crop selection (eg CCN, stem rust, canola blackleg)

Insects Some pre-emptive treatments used, especially for canola & virus control, otherwise, treat as needed. Close monitoring of crops can be critical Need to identify beneficials as well as pests Gaps include thresholds - the understanding of effect of beneficials, and the impact of pesticides

Grower’s situation & attitude to risk is important

Retrospective monitoring - Improvements in water use efficiency