After two seasons of considerable crop variability FGinsight will be following wheat fields on four farms from Kent to Berwickshire, tracking growth stage development through the season together with what agronomic actions may be necessary. This update relates to early May.
After T1s were applied in late April the warm weather has seen crops race on. Leaf two is fully out on Crusoe with leaf one now poking out. Leaf two is almost fully out on Siskin.
The concern now is stem length. We will have to look at an ethylene producing PGR in the T2 mix.
Both crops have the same number of tillers but there is a noticeable difference in biomass. Both were strip-till drilled using a Sumo TDS. The Crusoe has filled out more so theoretically should be the better performing crop. But Siskin’s yield genetics are better – it’s anyone’s game.
Both crops are destined for a further 90kg N/ha of ammonium nitrate. Tissue testing will be employed to look for nutrient deficiencies. Testing on Siskin has already shown that boron, copper, sulphur and magnesium are in short supply. That is no surprise as T1 mixes were big enough already without too many trace elements going in. However, going forward I think we will have to look at including boron as part of T0 applications due to low readings in all previous tissue tests.
Despite the hot weather Crusoe only has low levels of brown rust. The current threat for both crops is septoria and in some cases some stem-based browning, which has penetrated the stems. But there is little that can be done as we won’t get sprays that deep into the crop canopy.
Septoria is killing leaf five but with the gap between T1 and T2 applications likely to be no more than three weeks we should be in a protective situation at GS39. Fungicide choices will be based around Ascra (bixafen + fluopyram + prothioconazole), Elatus (benzovindiflupyr + prothioconazole) and Adexar (fluxapyroxad + epoxiconazole), depending on T1 product choice, and there will be no need to move to higher rates given where we are now.
The weather has hampered farming operations and T1s are now going on. Skyfall is still ahead of Zyatt with leaf two half emerged, Zyatt is just tipping.
Skyfall has some septoria and will get an azole + SDHI in the form of 1.0 l/ha dose of Aviator (bixafen + prothioconazole). Zyatt also has septoria on the lower leaves, and mildew, and will get Proline (prothioconazole) plus Bravo (chlorothalonil).
Flag leaf mixtures are yet to be decided, but GS39 will be the time to apply a final dose of N in the form of solids. Rates will depend on what satellite images reveal. More N is likely on areas of higher biomass to ensure protein requirements are met for bread making where more yield is expected.
Bringing some of the N forward has probably helped crops catch up but the biggest factor in growth rates was a week of 20°C plus.
For the fields of Kerrin we are in the ‘lap of the gods’. Five days of 25-27°C temperatures with wet soils and plenty of nitrogen to suck up saw crops get going two weeks ago but we soon went back to the rain and cold.
What is particularly interesting is node development. On the outside it didn’t look like a great deal was happening but the first node just kept on extending and the second node was visible just five days later. The danger is these crops will get a bit ‘leggy’. We saw last year the same happen to winter barley. They got too leggy and when the June rain and winds came they just collapsed.
Currently the early drilled field is at GS33 with leaf three 80% emerged on the main tiller. The later drilled crop is approaching GS33 with leaf three around 60% emerged on the main tiller.
I’m pleased I urged growers to get on with T0 and good PGR strategies as T1s have been hampered by wind and continual wet weather. We’ll have to keep an eye on things but a PGR might be needed at GS39. I would advise growers to check product cut off timings and remember that ethylene producers like Cerone (2-chloroethylphosphonic acid) only shorten the upper nodes.
As usual the prime concern is septoria, although yellow rust is easy to find too. Fortunately, both are confined to the lower canopy. However, that picture could change as although septoria is in the base of plants now, those levels are significant and in Kerrin (pictured) leaf five is very upright. It could transfer the disease into the upper canopy. Leaf two is responsible for around 23% of final yield, and leaf one, 43% so effective protection is vital.
Leaf emergence is now very much temperature dependent and I expect T2 sprays to be going on around the last week of May, if the weather stays on course. The levels of septoria in the base of Kerrin do worry me and looking forward I plan to use a robust azole + SDHI mixture +/- CTL depending upon disease pressure.
Unfortunately, we are two weeks behind where we should be and the reduced biomass means that we are probably going to see a slight loss in yield potential. It is almost inevitable that the time from flag leaf (GS39) to ripening will be condensed, impairing grain fill.
Grafton has leaf three fully emerged while Lili is a little behind with leaf three just over half out. Across the farm we have wheat crops from GS30 to GS32/33. I don’t think I’ve seen such disparity.
T1s are still to go on and by calendar date it is the latest I can remember. We had significant rainfall in the first two weeks of April but we haven’t had so much rain since. But T0 opportunities have been few - we’ve missed the worst of Atlantic depressions, which have slid south of us, but we’ve picked up the tailwinds. As a result T0s have been all over the place.
I can’t find any yellow rust but we have septoria and we will have to look for some kick back at the T1 where gaps might become extended. This will probably be 1.0 l/ha Ascra. However, due to the spread in T0 application dates some crops will fall nicely into a three-week window. Here we’ll probably go with Adexar.
We will look at further nitrogen applications to try and offset a reduced ripening period but our Scottish land is close to NVZ limits, and we don’t want over cook it. Further leaf testing is planned and I suspect we will find a boron deficiency. This will need to be rectified as it is a valuable element for grain setting.