Trial No: 03CO07SP

OBJECTIVE: To determine differences in efficacy of in-furrow, seed dressing and foliar fungicides in managing stripe rust in the Corrigin area in Wyalkatchem wheat in 2003.
LOCATION: West Corrigin
AGRONOMIST: Sally Porter

RESULTS

Gross Margin Assumptions & Product Costs

Table 1 Quality Sample results

Table 2 Gross Margins

 TRIAL DETAILS

Soil Test ppm

Trial Discussion

While the aim of the trial was to assess Stripe Rust management options following the first official finding of Stripe Rust in WA in August 2002 there was no stripe rust present in the trial in 2003 and thus the comparisons in the trial are in the absence of rust but with low levels of Septoria nodorum and/or Yellow Spot.

Compared to the control (Premis) there was no significant difference in yields compared to the other treatments.

The site was Predicta-B tested and the only visual disease pressure present throughout the year was low levels of Septoria nodorum/Yellow Spot (visual assessment only, not tested).

The trend in the yields was for there to be no effect of the fungicide treatment compared to the control when a narrow-spectrum seed dressing (Baytan and Real) plus either a narrow- (Turret) or broad- (Tilt and Exp1) spectrum foliar fungicide was used. Similarly when a broad-spectrum seed dressing (Jockey) or in-furrow treatment (Triad IF, Impact @ 200ml/ha or Impact @ 400ml/ha) with a narrow-spectrum foliar fungicide (Turret) was used there was there was very little difference from the control. However, where a broad-spectrum seed dressing (Jockey) or in-furrow treatment (Triad IF, Impact @ 200ml/ha or Impact @ 400ml/ha) with a broad-spectrum foliar fungicide (Tilt or Exp 1) was used there was a trend to an increase in yield, presumably attributed to the suppression of the Septoria nodorum/Yellow Spot.

Impact @ 200ml/ha outyielded Impact @ 400ml/ha when used in conjunction with Tilt and Exp 1 foliar applied. The difference between the two rates of Impact seem to have been noted in other Landmark trials in WA in 2003 and may be due to the seed and the fertiliser going down the same tube and the Impact having a toxic affect on the seed. If this is the case it is not reflected in the plant counts taken at 6 WAS where there were slightly more plants per square metre in the Impact @ 400ml/ha plots (165 plants/m2) than in the Impact at 200ml/ha plots (162 plants/m2).

For all treatments protein was consistently around the 10% (9.8-10.4%) mark and screenings consistently low ranging between 2.12% to 3.17% (Table 1).

Summary

Where the disease spectrum includes diseases like Septoria nodorun and/or Yellow Spot a broad-spectrum seed dressing or in-furrow fungicide followed by a broad-spectrum foliar fungicide may result in a yield increase and give the best gross margins (Table 2). In a rust epidemic year these broad-spectrum control measures will help in the management of the rust however and increased number of strategically timed foliar fungicide applications may be necessary. To establish this more trials with similar protocols will need to be done when rust is prevalent. It would be pertinent to leave a completely untreated control and also have the seed dressings, in-furrow treatments and also the foliar treatments applied singularly as well as in combination as was done in the current trial.