Key Points
These trials were established to identify the dose rate response characteristics of key fungicide ingredients applied at flag leaf.
- In South Canterbury where the key disease was late leaf rust infection there was significant evidence that Proline was less effective on leaf rust and showed a trend of retaining less green leaf compared to Opus. However these differences did not lead to lower yields from Proline compared to Opus.
- In South Canterbury, with a late disease incursion, the 2 spray Opus and Comet programme and a single application of Opus and Comet at GS 39 had the highest margin.
- At Methven where stripe rust was present from flag leaf emergence, there was significant evidence that Proline at the lowest rates was less effective on stripe rust and showed a trend of retaining less green leaf compared to Opus.
- These differences lead to a trend of lower yields than those achieved with Opus at equivalent rates and the poorest yields and returns coming from Proline at the lowest rates.
- At Methven the 3 spray programmes with a first application of Opus or Proline at GS 32 had a higher yield and margin than the 2 spray programmes that commenced at flag leaf.