A good start has been made to drilling spring crops, with the earliest drilled now emerging in the more forward areas. After a very mild winter, the colder temperatures during the first half of April slowed development in all winter crops, with many fields actually going backwards. The cold night-time temperatures have been very stressful to winter crops, hampering nutrient uptake causing purpling, yellowing and tipping of some leaves. However warmer temperatures and rain over the last week has improved everything, with all winter crops now looking much better. What is clear given current pricing it is more important than ever to optimise fertiliser applications to maximise the efficiency of utilisation of N, P and K. Soil pH is key – make sure this is above 6.2 for winter and spring crops. Granulated lime at around £125-135/t is excellent value and we should see a lot more of the granulated lime being applied to improve NPK utilisation. Correct use of foliar feeds also has an important role to play, where often it is not the amount of N applied that is the limiting factor, but perhaps sulphur or one of a number of micro-nutrients.
The size of canopy at GS30-31 is a good indicator of future lodging risk, with larger canopies associated with greater lodging risk. Assess lodging risk on a field-by-field basis, also taking account of the field soil residual N and lodging history, and the varietal lodging resistance score. Numerous other factors contribute to crop lodging including sowing date, early growth over the winter months, and late season extreme weather events.
Against this background, a programmed approach made up of a number of treatments promoting shorter and stronger stems is essential. Plant growth regulator (PGR) choice, timings and rates all impact the outcome achieved. Early sown crops with thick canopies are most at risk of lodging, particularly if of a weaker strawed variety, and will require a more intensive programme to minimise the risk of lodging
With a better understanding of disease resistance to single-site triazole, SDHI and strobilurin chemistry, maintaining the efficacy of this chemistry is critical to being able to continue to control wheat and barley diseases effectively. Multi-site chemistry is key to prolonging the efficacy of the single-site chemistry. Chlorothalonil (CTL) was the mainstay of multi-site activity for years, but with its loss two seasons ago now, folpet, available from Syngenta as MIRROR is regarded as the most effective replacement.
Folpet is a multi-site active, and all manufacturers are advocating the inclusion of this active into wheat and barley programmes, not only to prolonging the single-site actives, but to improve disease control also. Its inclusion improves Septoria activity in wheat and gives some improvement of Ramularia in barley. Like CTL, folpet is a contact ingredient only with no systemic activity, protecting the surface of the leaf by preventing the fungal spores germinating on the surface of the leaf.
Early weed control – Annual Meadow Grass In Spring Crops
If Annual Meadow Grass (AMG) is to be controlled in spring crops, this must be done as soon as possible. This will be done before the timing for controlling broad-leaved weeds (BLW) in spring cereals. There are a number of product options, but all must be applied either pre-emergent or in the case of one, very early post-emergent of the crop.
Applied pre-emergent, all work by residual activity to control the AMG. Since residual herbicides require sufficient soil moisture to be effective, so their performance will be compromised in drier soils. This is the primary reason for the variable performance of AMG control achieved in the spring. Best control is achieved when applied onto a damp seedbed, keeping the water volume up and travelling slowly. To maximise efficacy and crop safety, ensure the label guidelines are strictly followed.