diagnostic agronomy, dubbo, 18 th october 2010 allan mayfield, clare, sa
TRANSCRIPT
Diagnostic agronomy,Dubbo, 18th 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
DiseasesDiseases 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
efficiencyWater use efficiency (kg/mmGSR), 5 year average, wheat, Redhill, SA.
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