T0 And T1: To Merge or Not to Merge – Farmers Guardian – Neil Watson, Dick Neale
On poorer crops, the desire to cut inputs on clean but backward crops is understandable and there is perhaps scope to reduce overall fungicide spend from 130/hectare to 100/ha by...
On poorer crops, the desire to cut inputs on clean but backward crops is understandable and there is perhaps scope to reduce overall fungicide spend from 130/hectare to 100/ha by cutting at TO. But only where septoria signs are not visible and risks are low, according to Hutchinsons UK technical manager, Dick Neale.
The firm’s technical support manager, Neil Watson, also highlights that only five wheats on the Recommended List have juvenile yellow rust resistance, potentially aiding the disease’s development in a late-drilling, largely frost-free year.
Both acknowledge, however, that late-drilled crops racing through growth stages may mean TO and TI come together, but urge growers not to simply cut a quarter of their fungicide spend just because of this and the fact some crops may look to have lower potential. Product choice is important, they add.
“With few leaves, it is essential to keep them all green,” says Mr Watson.
“A triazole-based TO can aid tiller survival, and there may be PGR as well as foliar and stem disease control benefits from products such as Prosaro or Sparticus, at this timing. Remember, though, that some actives, such as tebuconazole, cannot be used pre-GS30.”
Mr Neale suggests strobilurin products may have a place at TO, depending on yellow rust presence, where their eradicant capabilities are questionable.
He says: “Perhaps most importantly, though, this is the last chance to use chlorothalonil, and one litre/ha at GS30 will provide growth regulation, tiller survival and rust control.
“But with crops likely to rush through growth stages if drilled late, T0 may be hard to time and may merge with T1.
“It is here where the additional option this season of BASF’s RevyStar, its new azole plus established SDHI, will be worth considering, given its average 0.3-0.4t/ha yield respnse in trials.
“Timing will depend on septoria pressure at T1. If high, then RevyStar plus Bravo makes much sense.
“If T1 pressure is low, then perhaps Sparticus or Ascra Xpro plus Bravo will suffice, saving RevyStar for T2 alone.”