Check wheat for growth stage to ensure correct fungicide timings – don't make assumptions.

After probably one of the longest, coldest, wettest winters on record wheat crops are just beginning to green up and actually starting to grow. However, it is of great importance that growers do not assume that crops are backward in their development stage as it is quite apparent from actual plant dissections for both ear and node development that internally the crops are motoring very fast.

This is the advice from Ron Granger, wheat breeder with Limagrain UK Ltd. "I have been monitoring plant development for many years at our wheat breeding station in Suffolk, where we have a wide range of recommended list varieties. Our plots were drilled back in late September and  two weeks ago there was the expected wide range of growth habits for the relevant varieties from prostrate through to erect types."

"In a more normal season you would not expect all plants to be at the same developmental stage, you would normally find a spread of development stages across the range of varieties.  However this week when dissecting for ear development it is clear that plants are all at a similar developmental stage – terminal spikelet. Plants are also racing through node development and the 1st node is detectable across most varieties.  So it is really critical to dissect crops to see where they are rather than relying on visual development."

Leaf production is also unusual in many cases with leaf three is just starting to or already emerged. This is confirmed by Dick Neale of Hutchinson who believes it will have a major influence on both PGR and fungicide applications. "All leaves will be essential for the final yield potential this season, and as leaf four is already fully out, it will play a bigger role in the final yield especially in the more open canopies- it could be worth as much as 10-15%."

"Early season fungicides should have been applied or need to be applied very soon and if planning a single T1 spray in the first week of May I would recommend an eradicant SDHI be included in the mix as well as a low dose of PGR , not just to prevent lodging, but more so because of the PGR ability to even up tillers so that come ear emergence the tillers are all at a similar size."

"Careful crop monitoring will be essential - throw away the calendar and don't make any assumptions on timings.  Forget sprays in the context of T0's and T1's and look at what the leaves are doing. A normal T1 would be timed at leaf 2 emergence, however we are seeing crops now that have had leaves 3 and 4 out for some time – and they will be susceptible to infection – keeping these leaves clean will be critical to protecting yield. The next spray should be the 'Leaf 3' spray, followed by a spray when leaf 3 is fully out and leaf 2 is emerging. "