March 2010 Archives

The last few days have seen a dramatic change in all crops with a lot of cereal crops  now at the T0 stage, and the decision has to be made as how to proceed with tank mixes.

From my perspective, where I was hoping to include a PGR before stem extension for root promotion, I now feel that where Atlantis is to go on. This won't happen as the priority must be the grass control.

This will mean that the PGR programme will be all done at T1 which I am aiming to be within three weeks of the T0.

Disease, apart from Septoria, is not showing as yet, though the majority of varieties this year are rust prone and I don't believe the inoculum has gone away because of the cold weather.

Soil temperatures have at last warmed up and conditions are now ideal for the application of Atlantis type products on wheat. Unfortunately the weather forecast between now and Easter doesn't look good and spraying opportunities look few and far between.

The bulk of the wheat crop looks likely to hit T0 in the first week in April, hopefully the majority of outstanding blackgrass treatments will have gone on by then.

I will be using a chlorthalonil/ triazole/growth regulator mix on those varieties susceptible to yellow rust but mindful of cost on Xi 19, Claire, Alchemy, Humber, Gladiator, Scout and Panorama which are all resistant to yellow rust I will use straight Chlorthalonil.

I would still urge those held up by the weather to try not to tank mix fungicides and growth regulators if at all possible. Crops are relatively clean, little rust can be found and few crops are so thick and forward that PGR programmes need to start immediately.

Welcome rainfall from Friday 19 and through the following week has seen crops take off at a rapid pace. With the crops being dormant for so long we will now see the early part of this season as a race to keep up with the growth stages.

Winter barley has greened up but is the slowest to get going, looking at T1 application week commencing 5 April, there are many crops with a complete absence of cleavers/broad leaved weeds. With the absence of fluoxy/prothio will go down the route of izm/cyprodonil based upon good results from previous years trials, also has good compatibility range and as it is a one can solution saves on packaging and the number of products to fit in the tank.

Winter oilseed rape is reaching for the sky. Some crops must have put on 3-4 inches of growth in the last week, it is noticeable that the hybrids (particularly Excalibur) are growing the fastest. I have never been convinced about autumn vigor, but spring growth definitely rapid.

What a difference some sunshine makes ground is really dried up now and any spring drilling is taking place at rapid pace in to on the whole very good seed-beds as soil temperatures start to warm up and if there is some moisture i would expect these crops to establish very evenly.

Most winter crops have received some nitrogen and are starting to wake up and again with a bit of heat in the soil I would expect them to start and move on fairly quickly and we will all wait with baited breath to see what will happen with disease levels, particularly yellow rust.

Some winter barley crops have patches in them which is being suspected as snow rot but unfortunately apart from a bit of TLC there is not a lot we can do at this moment. Light land and any soils suffering from soil heave will nedd a roll and some manganese applying.

As winter barley crops move rapidly i will be looking to get the second split of nitrogen on to the malting crops and will assess the T1 fungicide/growth regulator programme as the crop moves on but will be based around strobilurin/cyprodinil/prothioconazole depending on disease pressure at time.

Since last writing the cold weather has continued to control crop development or the lack of it. This has been made worse by the fact that we have had no rain to help take nitrogen into the rooting zone. Having said this we have now had some rain over the weekend and temperatures have risen.

There is alot of frost damage in wheat crops with wet patches in fields now beginning to die back as the entire plant has been heaved out of the ground. There is little that can be done to remedy this situation but in less severe cases, where the roots are exposed but the plant is still anchored, rolling may help.

The cold spell has not helped with attempts to build canopies in rape crops. The crop has taken up nitrogen and gone a good colour but has not done much growing. With milder and wetter weather now upon us this situation should change rapidly. Fungicide choice at stem extension will be interesting this year.

At last there is some warmth in the sun, though night temperatures are still below freezing. Dry fields are giving an ideal opportunity for applications of early nitrogen and P&K fertilisers.

Crop growth is barely evident, so nitrogen will not be taken up yet. But in dry conditions there is no danger of leaching and the fertiliser will sit there until needed.

In a "normal" year, T0 fungicides would be applied about 20 March, but with slow growth so far this year it's likely to be pushed back towards the end of March/early April. It is still too cold for Atlantis application and this may eventually coincide with T0 spraying. If so take note of the Bayer recommendations on tank mixes.

Where over-wintered meadowgrasses and broadleaved weeds are the target in wheat, conditions are suitable for the use of Othello, though in some cases, where weed size permits, it may be sensible to wait for spring weed germination and control all with one spray.

We've just had a week of dry weather and what a huge difference it has made. A cold dry wind has dried soils very quickly, it's hard to believe we were still under snow at the start of the month.

Fertiliser spreaders have been busy and most cereals will now have received their first application of nitrogen plus sulphur. Spring barley drilling is well under way in the earlier areas and this week should see most others catching up.

Seedbeds may be cooler than normal at this time but soil conditions look excellent, do aim to get some N, P & K into the seedbed before drilling to maximise efficiency of availability of the nutrients.

As ever oilseed rape shows the greatest variation between fields. Over the last month or so we've had significant frost without snow cover and small canopies have literally shrunk nearly out of sight from the field gate. Those established by early September are looking well and should soon begin moving more rapidly.

Although days have lengthened and the rain has dissipated, soils remain very cold and crop development is being held back.  Nevertheless, most fields have been accessible by machinery during the last two to three weeks, allowing first nitrogen and sulphur top dressings to be applied to wheats, barleys and oilseed rape.

Low soil mineral nitrogen levels have resulted in all crops receiving a top dressing in early March.  We've been utilising variable rate spreading to help even up canopies with this initial nitrogen application. In addition, we have also been evaluating the success or otherwise of variable seeding rates in winter wheat now that a final assessment of plant population and establishment can be made. 

There is considerable frost lift in some cereal crops, especially on chalk soils and lighter soils where seed was drilled a bit too shallow - the worst areas will be targeted with the rolls.  There is a risk of poor anchorage this year in many crops where root development has been restricted by cold wet conditions and where frost lift has occurred. 

At last, some blue skies and settled weather has given everyone a lift.  A flurry of field work has started with fertiliser spinners aplenty and drilling of spring barley and beans on the more free-draining soil types. 

Oilseed rape crops have woken up and now with a good supply of nitrogen underneath them are all ready for rapid spring growth.  Where fields were not treated with a pre-em then look out for troublesome weeds such as thistles, mayweed and cleavers. 

Where populations of these weeds are high consider treating with clopyralid and picloram.  Make sure to apply the herbicide before the flower buds are visible above the crop canopy so as to avoid the panic phone call about whether the cut off timing timing has passed. 

Some oilseed rape crops have the two extremes of canopy size in the same field, ranging from thick forward areas to others totally skinned to the bone by pigeons.  Such variation in canopy size within the same field makes for interesting nitrogen management of these crops. 

The recent prolonged dry spell has allowed good progress with fieldwork, but how long before we are saying we need some rain!

Its important not to force spring crop seed-beds, and in many cases previously ploughed or cultivated soil has had to be 'moved' to dry it out.  That said where spring beans and spring barley has been planted seed-beds look good.

Spring beans will receive a robust pre-em, as post-em options are limited, expensive and un-reliable.  Avadex (tri-allate) is being used pre-em on some spring barley fields where we have bad black-grass.  With both these pre-em treatments we are dependant on some moisture before too long to achieve reasonable activity.

Some autumn sown winter barley and wheat crops have suffered frost lift, especially on thin chalks.  The worst affected fields will be rolled.  Unsually there is also some fields of rape where frost lift is also evident.

In the previous Crop watch report I commented how well the crops had come out of the winter, however most of them had been insulated with a cover of snow,protecting them from  freezing temperatures.

Febuary has seen a mean temperature of 2.4 degrees,  with a maximum of 7.3 and lowest of -2.6 degrees, March so far has fared no better. Soil temperatures  got to heady heights of 4.4, but have soon dipped to 3.3and below Winter rape crops with large canopies have lost their  outer leaves,  the nitrogen will have been dissapaited to new growth.

In crops with large canopies I have found evidence of stem cracking, which is associated with frost damege. This pheneomen appeared a few years ago when the term wind chill factor entered our vocabulary. Having done some reaseach ,  I have found a scientific paper that  suggests that large canopied rape is more susceptible to damage from low temperatues and increasing day length.

Since my last report we have had further bouts of snow and sub zero temperatures, this has severely restricted any field work. Despite the weather the ground conditions today are pretty good particularly on the min till ground.

Manganese deficiency is an issue on lighter land on quite a few cereal crops (I think partly due to mild frost lift), will apply managnese at the 1st opportunity

All carbetamide applications to winter OSR have been made during the odd occasion when soil conditions have allowed. Pigeon control has been at the top of most clients agenda with the effort having paid off, where little or no control fields now look pretty bare and yield penalties will have been incurred.

Later-sown/backward crops will have low rates of N+So3 applied this week if conditions allow.Will also have a go at applying remaining graminicides+fungicide this week. Crops generally seem to have come through the winter well and the 'big'pre christmas crops now look more manageable, we will not apply any N to these crops for at least two-three weeks.

The continued cold conditions and rainfall at the end of February continue to frustrate farmers and agronomists alike. Soil temperatures are hovering around 5C and we really need 8-10C and obvious signs of growth before we start applying Atlantis or Pacifica to Wheat crops. T1 normally occurs around the third week in April and working back 4 weeks T0 sprays should be applied around the third week of March.

If blackgrass application dont get applied before T0 then we have major tank mix problems looming. Current advice is to apply Atlantis and Pacifica alone except for Biopower and certainly not with Bravo ( Chlorthalonil ). Lets all hope the weather improves otherwise it could get rather tricky towards the end of March!   

Where Populations of Blackgrass are high or plants are large we need to maximise the control levels achieved and in these situations it makes sense to use Pacifica rather than Atlantis because its higher active ingredient loading can provide higher levels of control.