November has passed like a scene in the Bill Murray film Groundhog Day with every day being a repeat of the last one, dull, dry and still. This makes your friendly agronomist look a fool as every week he declares "that's it for the year, put the sprayer away we won't get any more spray days!" This is followed the following week by "let's spray that late drilled wheat".
With such a mild and prolonged autumn, crops look really well and a flock of a few thousand sheep could fatten over winter in
Rain in early November and some perfect spraying conditions subsequently have resulted in rapid blackgrass emergence in wheats and a considerable amount of Atlantis/Horus (iodosulfuron + mesosulfuron) being applied. Soil moisture has also activated the residuals to the extent that the later sown wheats contain some sick looking blackgrass.
There is still some follow up Atlantis/Horus to be applied and while conditions remain suitable, with soil temperatures still around 10C, it will be sprayed if conditions allow. In some cases larger and more difficult blackgrass warrants the addition of a contact + residual partner.
Wheat crops are a mixed bag with some very lush crops plastered in mildew and some of the earlier drilled crops still struggling to emerge. Barley tends to respond to an autumn fungicide in such circumstances more than wheat, but there has been some mildewicide applied to struggling wheats especially on lighter and chalkier soils.
A quick glance at the calendar tells me it is December this week, hard to believe after the mild weather we have had recently.
Rape crops continue to race away and some are carrying huge canopies going into the winter. Soil temperatures have now declined enough to start applying Kerb (propyzamide) or Crawler (carbetamide) but given the size of some crops getting a residual herbicide down to the soil surface will be a problem. In large canopied crops we may have to wait until frosts open the crop up.
Phoma levels are low at the moment and opinion is split on the merit of adding a second fungicide whilst traveling through the crop. Aphid numbers are still high in crops and I am adding an insecticide to control these: cabbage stem flea beetle and rape winter stem weevil.
More advanced wheat and barley crops are carrying high levels of disease especially mildew. I have treated a few barley crops on light land, but I dont think the disease is worth treating on wheat crops at the moment, hopefully once we finally get some frosts this will sort the problem out.
The unusually mild weather throughout November has been a great help to all the late drilled crops in the area. With a late maize harvest there has been a significant acreage of wheat planted later than usual this year.
The vast majority of these crops have taken as little as 12 to 14 days to emerge after planting. The mild spell has also allowed later drilled crops of oilseed rape and winter linseed to put on growth and establish better before the onset of winter. Some of the August drilled oilseed rape now has such a large canopy that it now has the potential to become a management headache rather than being straightforward.
Pre-emergence herbicides have either worked really well or grass weeds are slow to emerge this autumn. I have several known brome sites where there is very little sign of Brome emergence and certainly not enough to go with an Atalantis (iodosulfuron + mesosulfuron) or Broadway Star (florasulam and pyroxsulam) application.
This is unfortunate as the mild weather would have made for ideal timing for either of these products, which are temperature dependant for efficacy. Volunteer beans have now been controlled in many crops, particularly those established using non-inversion cultivations.
All crops generally look very well as the long run of mild weather continues. With very little rain in the past month most autumn spray programmes have now been completed.
A lot of Atlantis has been applied to small blackgrass in ideal conditions so hopefully control will be maximised. The main issue affecting cereals at present is the high levels of disease, particularly mildew.
Most barley crops are carrying some mildew but varieties such as Cassia, Cassata and Saffron are suffering particularly badly. With such mild weather the mildew has had a free run with no frosts to check disease development. Although exceptional, some crops of barley will warrant a mildewicide so that the barley plants can maintain shoot numbers, biomass and ultimately yield.
What happened to the promised October snow!
Since my last article we have still not had any significant rainfall (or snow!), just days of mist, and unseasonably warm temperatures.
The temperatures have encouraged rapid blackgrass growth, if the blackgrass has 2 or more leaves I am still encouraging autumn Atlantis use. At the same time we have to be mindful that this product needs to go onto a dry leaf, and dry on. Needless to say the spray window each day is not that long. Atlantis should be applied with a residual partner, my early results with prosulfocarb as a tank mix partner are looking favourable.
The key observation concerning all crops this autumn has been the prolonged unseasonably mild conditions. We've had enough rain to get full germination now in all the cloddy, baked-out backward areas, but it doesn't look as if there was enough residual herbicide hanging about to be successfully reactivated. Consequently over the last week or so I've seen a considerable emergence of blackgrass in places, and follow up treatments are now becoming necessary. The good news is that the mild, growy conditions should mean the Atlantis-type follow ups should work very well.
The mild conditions have brought on an onset of disease, particularly mildew. Net blotch and rhyncho are being found in barley, along with low levels of both brown and yellow rust in wheat. I am taking note of this, but apart from the worst mildew cases in barley on thin soils, I'm not yet taking remedial action. What it means though is my early spring fungicide applications are likely to be extremely robust.
The mild, damp weather continues, with heavy mists this week reducing the opportunities for spray applications onto anything like dry leaves. We shouldn't be lulled into a false sense of security; last year the really cold weather didn't start until the last week of November.
Oilseed rape crops continue to grow rapidly and some are now above knee high (depending on the height of your knees!). The first few phoma lesions are just starting to appear, even in resistant varieties, and it's a good time to get on with a fungicide, provided that the crop leaves are reasonably dry. The addition of a sticker/extender surfactant to the fungicide is beneficial when spraying conditions are less than ideal.
Cabbage stem flea beetle larvae can be found in some crops. A pyrethroid insecticide can be added to the fungicide if necessary.
Justin Hayward once sang: "my life will be forever autumn" and this is certainly how things feel in the South West at the moment. Crop growth has carried on unhindered and early November drilled wheats after grass leys are now fully emerged.
The damp, mild weather has allowed grassweeds to emerge, especially since the last spell of heavy rain wetted through cloddy areas of strong land. Residual herbicide performance has not been as consistently excellent as last year.
The mild conditions and good levels of blackgrass emergence means conditions are ideal for autumn contact materials and a dry spell this week should see a lot of spraying completed. Winged aphids are being detected in cereals, therefore, an aphicide will be prudent.
Insecticidal seed treatments on early-sown crops will be nearing the end of their useful performance so should also be treated.
Most oilseed rape crops are growing with fury like it was spring and are at the eight leaf stage. These crops will need a PGR fungicide treatment based on metconazole or tebuconazole if not already done so. Ensure to use a fungicide that also delivers a punch of phoma treatment as, since the last seven days the risk of this disease has increased much because of the recent rains and the higher than normal seasonal temperatures.
The early drilled winter wheat and barley crops are at the four leaf stage. So far slugs have posed little or no problem, but rain has brought up these dreaded creatures and there seems to be significant damage in some fields, particularly those just emerging (late drilled fields) and where the seed-beds are cloddy.
Check crops carefully and apply slug pellets as soon as soon as conditions allow, but remember the maximum single application doze of 210g/ha and 700g being the maximum dose per calendar year for metaldehyde.
Harvest for most is finally finished although a few large growers are still struggling and there a number of fields that can not be lifted. While growers are now preoccupied with preserving quality in store and grading seed for export, it is worth considering next season.
This season has shown that marginal land is marginal for a reason and this is also true for virgin land. While combinable crop growers reduce costs and increase profitability by increasing scale, most potato growers need to reduce the number of marginal fields they plant instead.
Furthermore, it has also shown that if a field has a past history or is high risk for powdery scab then there is only so much variety, and in the case of seed growers fluazinam, can do to reduce it. These fields also run the risk of potato mop top virus that has also proved problematic.
It is all very well and good saying: "once the frosts come, most of our present problems will go", but when is this going to happen?
All week the queries come in about decisions on whether to spray ccereals with fungicides. Winter barleys in this area are covered in mildew and quite rank in growth. There is some debate about the thickness of the crop needing to be controlled and if control of mildew does occur, will this lead to too many tillers being left and, therefore, a possible loss in yield.
Certainly later barleys are at risk if this weather continues, plus the fact that aphids are readily being found in many crops, meaning a trip through is likely anyway. There has already been some fungicide treatment applied and I suspect more will be done.
Over the last 10 days, we have had approximately 25-40mm of rain across the whole region, which has been enough to get all crops chitting. However, it has by no means had any major effect on the big soil-moisture deficit in this area.
The rain has arrived too late for some oilseed rape crops and I think somewhere in the region of 300-500 acres of rape has been ripped up - not all mine - in the area and either replaced with a second or third wheat or winter oats.
I have quite a few acres of rape that is still only at cotyledon to 2-3 true leaves which we are leaving to see if they make it through to the spring. With soil temperatures still at 12C, crops are growing quickly, especially where they have either poultry litter or sludge cake underneath them.
This weekend saw a couple of glorious sunny days. However, with the mercury dropping below zero overnight I guess this doesn't really qualify as a late Scottish summer.
Most growers have finished combining, but there is a considerable amount of straw waiting to be baled. Bean crops seem intent on providing work for those who get bored between Christmas and New Year. Potato lifting is still proving to be a trial with self-propelled harvesters being imported from further south to try to salvage potential crop write-offs.
In general, oilseed rape crops are looking well although growers had to be vigilant in preventing predation by a slug population, which has enjoyed the monsoon conditions. Whilst most growers choose rape varieties with a good resistance to light leaf spot, a robust autumn treatment is required to fulfil yield potential.
Moist conditions have evened crop establishment of second and later drilled wheats. After the rain, crops that are still emerging through heavy, cloddy seed-beds should be carefully monitored for increased slug activity.
In winter cereals, dry conditions had reduced the impact of pre/peri emergence residuals. This has been apparent by high populations of volunteer rapeseed. However, following the long-awaited rain, crop volunteers are now clearly affected by the recent uptake of these residuals.
Recent rainfall and mild temperatures have also prompted rapid grassweed emergence. Where significant grassweed populations have emerged, conditions are now good for sulfonylurea and residual activity.
Now we have had some decent rain - a good 1-2 inches last week - blackgrass control has become our top wheat management priority. This is especially so after a highly variable pre-em performance following such a dry drilling season with questionable seed-bed quality in some cases.
The combination of much needed moisture and the balmy October means blackgrass is coming through and growing away strongly, so we are making sure to target it at 1-3 leaves with full rate Hatra (mesosulfuron-methyl + iodosulfuron-methyl-sodium). Having used flufenacet as the base for our pre-ems, we are combining it with a pendimethalin-based residual for the greatest all-round activity.
Even if the blackgrass gets beyond three leaves we will keep on spraying to take full advantage of this season's very active early weed growth and whatever spray days are available. Our blackgrass trials research centre at Stow Longa, near Huntingdon confirms November invariably gives the best control with Atlantis (iodosulfuron + mesosulfuron) chemistry - 93% against 88% in December and less than 60% in April.
