|
CROP CRACK - 05-04-08
By WENDY FEARON
Clarendon Agricare - Wait For dry Conditions
Unfortunately ground conditions have improved very little since the last crop crack and the story remains the same with regard to fertiliser and spray applications.
Temperatures have improved though, which means the correct timing for PGRS will quickly pass. It is now time to assess which weeds are present in winter cereal crops and the T1fungicide treatment should also be planned as soon as conditions allow.
Fields where wild oats are expected to be a problem should be identified and sprayed once it is certain all the wild oats have germinated and are through the ground.
Winter Barley
The majority of crops remain advanced for the time of year with many winter barley crops varying from GS 30-32.It is essential to check crops as many weeds are now appearing. As temperatures have stabilized crops will move through the growth stages very quickly and weed control must be carried out as soon as possible.
Ally Max and Compitox should be applied once weeds are growing actively and will control a range of broad leaved weeds.Compitox and Oxytril CM may also be applied where awkward over wintered weeds such as fumitory, groundsel, red dead nettle and speedwells are present.
Starane XL should be applied if cleavers are present but also gives very good control of chickweed and forget-me-not.Starane XL is not as temperature sensitive as hormones.
Winter Wheat
A wide range of growth stages exists from GS 25-31.The T1 fungicide as well as controlling septoria and mildew should give good control of eyespot. Common Eyespot was a severe problem last year for some growers and severely affected yield. The disease causes lesions around the stem after flowering, which affect the uptake of water and nutrients into the developing grains. Some varieties are more susceptible than others and a fungicide applied at stem extension is the most effective time to protect the crop.
This T1 spray in our climate should consist of a robust conventional triazole and morpholine mix to clean up existing disease. Foil will give good Septoria and Eyespot control and Corbel should be added to clean up mildew. Opus Team will also give excellent Septoria and mildew control but is not particularly good on Eyespot. The same weed control may be applied as for winter barley.
Winter Oats
Most crops are still at various stages of tillering with early drilled crops now approaching first node. There is unusually high disease pressure on oat crops this year with many under severe stress due to wet conditions. Unfortunately weed control on winter oats to date has not been very effective and an application of Starane and Ally Max be applied.
Growth regulation and disease control are normally applied between first and second node (GS31-32).Growers of conservation grade oats should consult their protocol before applying any fungicides to ensure they are allowed within the scheme.
Grassland
It is important to remember that grassland herbicides are only effective when grass and weeds are growing actively and will not work effectively when there is a risk of low night temperatures. It is still too early to treat weeds in established grassland. Although weed control may be carried out in new leys at this time to ensure good control of seedling weeds. I will discuss grassland weed control in more detail in the next crop crack
|
