Key Points
- Although there was heavy infection of SLB detected early in the growth of the crop, this did not develop to significantly affect either of the two top leaves of the wheat plants
- All treatments gave a significant increase in yield compared with the untreated plants
- There was a strong negative correlation between the severity of SLB on leaf 3 assessed at GS85/87 and final grain yield. This emphasises the importance of controlling SLB in either a mild epidemic or in moderately resistant cultivars
- All fungicide treatments except two (single applications at GS39) gave significant reductions in SLB on leaf 3 when assessed at GS 85/87)
- Several treatments gave a low economic return (below $100.00). Good returns were afforded by both triazoles used alone or in mixtures with strobilurins
- In this trial, Claire warranted (at least) two fungicide applications. If strobilurins are included in the programme 0.5-0.75 l/ha in total of Amistar or Allegro provided a better investment than 1.0-1.5 L/ha in total
- Responses to fungicides may have been more pronounced under higher disease pressure, thus the research needs to be repeated