Most spring cereal crops continue to benefit from the recent hot weather with many racing through the growth stages in a matter of days after the early spring conditions. With temperatures now well above average and daylight hours considerably longer than for a crop drilled in early April, such conditions increase the likelihood of crop stress through too little moisture, or not enough nutrient availability to support the potential rate of growth. As a result many fields are beginning to show variation of colour and growth, and such variation is very difficult to address in a satisfactory way. Manganese (Mn) deficiency is widespread in much of our local soil types, and particularly damaging if not treated. Continuous cereal cropping, ground recently limed and dry soils all increase the likelihood of deficiency. Symptoms begin with small pale green speckles appearing throughout the leaf and these will progress to turn brown unless treated. Barley is particularly susceptible to Mn deficiency.
A young plant that is growing extremely rapidly is producing a huge amount of new plant tissue each day. This rapid growth is limited only by the availability of nutrients to synthesise biomass, dependant on soil fertility and the plant’s own root development to take up the nutrients. It is at this time therefore when nutrient deficiencies are most likely to appear and in doing so, suppress growth rates.
The application of a broad-spectrum trace-element mix along with key macronutrients during this time is a very useful and beneficial way to supplement the plant’s nutrient requirements during periods when availability does not meet demand, most likely to coincide with phases of rapid growth. Application of a balanced and readily available source of macro & micronutrients that is topping up what is being made available from the soil at this key time will minimise the adverse effects of restricting nutrient availability.
CEREAL HIGH N supplies 250gm N,38gmMg,45gm Cu and 15gn Zn per hectare
Disease pressure has been lower than that seen for a long time on winter cereals and fungicides are now complete on winter barley. T2 applications should now be complete on winter wheat crops.
Dry conditions have held back disease and at present all crops are fairly clean, but in our typically moist climate the likelihood of Rhyncho and Net blotch infections breaking out are inevitable unless controlled in good time.
Even where crops are considered to be clean, controlling Rhyncho early is much more effective than leaving it until it is seen. Once this disease comes into the crop, any eradicant treatment has limited efficacy, will stress the crop and increase the risk of Ramularia infection.
The young spring wheat plant isn’t subjected to the same disease burden as the overwintered winter wheat plant, therefore a two-spray programme usually suffices, with the T1 applied at 1st-2nd node, GS31-32, and the T2 applied at some point during booting, GS41-49. Whilst a large proportion of these crops are harvested as whole-crop earlier than the conventional combined crop, the feed quality of the harvested crop is very dependant on maximising grain-fill, therefore product choices and rates are similar to those of the winter crop, with significant yield responses to a proper programme.
Application of SELON at early tillering will have increased tiller and ear numbers and therefore yield potential, but will not have given any reliable strengthening of the straw. Stems that extend rapidly during the stem elongation phase (as has happened this season because of late planting and high temperatures) are more likely to be weaker and so there is a greater risk of lodging especially where the crop is being pushed on with nitrogen. SONIS can be used but its cut-off in spring barley is 2nd node, GS32. CANOPY is a very useful alternative, safe to the crop and able to be used right up to and including full flag leaf, GS39.
Because the application of SELON at mid to end of tillering (GS23-30) does give reliable later season lodging control in wheat, it is less likely than spring barley that spring wheat will need a growth regulator towards flag leaf unless the crop is particularly dense.