April 2009 Archives

I never thought I would be heard to be saying this, but I am delighted to see some rain. Hopefully, it will set these crops away at last.

Autumn crops on the whole have very shallow root systems and have struggled to pick up fertiliser, but I hope they will now move on and put down some biomass. Winter barley mostly has been treated with T1 sprays and we will make an assessment on disease levels and growth regulator requirements when flag leaf has emerged. We will be including chlorothalonil as routine for ramularia protection, as I believe it is as important a disease as in spring barley.

Winter wheat is now approaching final leaf 3 emerged and septoria control starts in earnest. We will be using epoxiconazole-based products, including boscalid (as in Venture/Tracker) or some mildew protection as required with Justice. It was concerning last week to read about shift in sensitivity to triazoles, so on the whole we will be using robust rates.

Weed control in autumn cereals is proving to be difficult. Where autumn herbicides have been applied it is relatively simple, as these have worked extremely well apart from the usual cleaver tidy up. Other crops due to open canopy and no residual are a bit more difficult, with myriad weeds germinating. But we are having to mix herbicide combinations to match weed spectrum, usually based on Harmony (metsulfuron-methyl + thifensulfuron-methyl) with addition of CMPP or ioxynil/bromoxynil.

This month must be one of the driest for a long time. We've recorded only 9mm of rain so far this April and crops have generally responded extremely well.

Dry surface conditions have encouraged cereal roots to deepen. The exception is wheat sown late into poor seed-beds, which has been very slow to improve.

Disease levels are low, although yellow rust has been found in untreated Robigus.

Forward wheat is about GS31 and ready for the T1 treatment, as most crops have had no T0.

Up to an inch of rain over the weekend was desperately needed. Most wheats look quite promising though there's some mildew creeping into the bottom.

The most forward crops are at T1 and it will be important to get the PGR right. They've already had 1 litre/ha of chlormequat and 0.1 litres/ha of Moddus (trinexapac-ethyl) and they'll get the same again along with fungicide - generally chlorothalonil with a good three-quarter dose of triazole, plus Flexity (metrafenone) if there's mildew present.

Most grassweed control has been completed and Atlantis and Pacifica (iodosulfuron + mesosulfuron) seem to have worked well. We don't have too many resistance problems.

Winter barleys look better this year than normal. They're not that awful yellow you often see - they seem more like wheat. Most are approaching GS32 and a lot of people have already applied fungicide. But it will be important to keep an eye open for rhynchosporium and net blotch after the wet weekend.

A precious few millimetres of rain last week has helped freshen crops and wash in some long-standing nitrogen.

Crop growth stages are 7-10 days later than usual. Leaf three is just beginning to emerge on the earliest winter wheats as attention turns to T1 product choice. Mixes will largely be based on chlorothalonil with either epoxiconazole or prothioconazole.

Septoria tritici pressure remains relatively low with eyespot yet to make much of an appearance. Mildew is likely to require specific control at T1 on susceptible varieties, as well as on late drilled crops where there is a lot of soft growth.

Be on the lookout for late flushes of annual broadleaved weeds such as cleavers, charlock and polygonums, as the recent rains and open crops are encouraging factors. If herbicide is required it can often be mixed with the T1 fungicide.

Winter barleys have greatly improved in the past month and have recently received their T1 fungicide.

Spring barley has emerged well and with such a large increase in area the maltsters must be rubbing their hands at being able to have such a potentially large crop to pick from. Meanwhile, some growers are scratching their heads trying to remember how to grow it, as "dad last grew it 15 years ago". This, along with spring rapeseed getting short, shows just how wet it was last autumn.

Winter oilseed rape is just beginning to flower in the earliest crops, while at the other extreme plants are shin high. Keep checking these late crops for pollen beetle at the green bud stage as thresholds levels have been exceeded in some cases, requiring a pyrethroid insecticide for control.

As spring rape emerges flea beetle can cause serious damage, so be vigilant for the shot-holing symptoms and treat if required.

We had probably the best March we could have hoped for in drilling terms, with all crops being sown into reasonable seed-beds. Rain, or should I say lack of it, is becoming a bit of a worry, and strong winds on 27 and 28 March have caused some crop loss and damage.

Winter barleys still show signs of stress and would certainly welcome warm rain. Dry weather slowed down disease, but net blotch and rhynchosporium are still evident.

T1 sprays are about to be applied with a prothioconazole/strobilurin mix. There are times when you wonder in disbelief who thinks up the names for these various products. But it's pleasing to see one named after a well-known Latin American dance that lives up to its name as it spins between distributor, grower and manufacturer.

Winter wheats on the whole look promising, the notable exceptions being late-October/early-November drillings. The appalling conditions in the autumn led to few crops receiving an autumn herbicide. This has led to a botanist's dream, as every arable weed is present and I keep telling myself that fumitory and ivy-leaved speedwell are not competitive.

No two years are ever the same and this season is throwing up a few surprises.

Bad light leaf spot in oilseed rape that has received two phoma sprays is certainly a surprise. Problems seem most prevalent in the more forward crops, which are receiving a robust fungicide preferably including prothioconazole.

With early crops at the yellow bud to first flowers opening stage, this is a slight compromise, which will confuse the main sclerotinia spray timing.

Some early control of sclerotinia can be expected from a spray at yellow bud, but beware of leaving the main spray too far into flowering.