Words by Bill Cabout, Ruralco Chemical Manager
In this Agrichemical Update we will be looking at what is happening on farm over the next 2 months regarding agrichemicals. We will be looking at cereals, ryegrass, white clover, maize, fodder beet and forage brassicas.
Cereals
The next few months are very important in getting it right with your agrichemical applications to maximise your quality and yield in these crops. These crops are all at different growth stages or have yet to be planted so timing of agrichemical applications is based on what growth stage the crop is at as well as what weed, and disease pressure is happening now and in the future. With disease, it is often better to look at a programme to prevent it rather than apply fungicide once disease is seen. it is often too late at this stage as the damage has already been done, and yield is affected.
Basic Programme for Autumn Sown Wheat is as follows.
Most autumn sown wheat is at or has gone past GS 30-31 at which a PGR (Plant growth regulator) need to be applied along with a triazole fungicide. If not using Rexade a wild oat spray will be needed to be used as well. Plant growth regulators are used to control stem length to prevent lodging.
At GS 32-33 further fungicide is applies. Choice of fungicide depends on the weather conditions and whether Septoria is present or not. If it is wet and or Septoria is present a SDHI fungicide will need to be used. If no Septoria present and it is dry other cheaper fungicides can be used. Remember Septoria has a relatively long latent period of 14-42 days depending on temperature. This means that the crop will be infected well before signs of infection are visible so often a preventative approach is best rather than waiting for the disease to appear and then try and cure it. At GS 39 flag leaf fungicide is applied. It is important that the flag leaf is protected as a lot of the potential yield comes from this time. Normally a SDHI fungicide is used at this stage. SDHI fungicides are used to control Septoria as Septoria is resistant to some other fungicides, but they need to be used with a triazole fungicide to help prevent further resistance. There are plenty of fungicides available. Talk with your rep to see if these will fit into your programme.
Most spring wheat crops have emerged, and an insecticide is normally needed to control aphids to prevent BYD virus. Once the crop reaches growth stage 20 a similar programme is followed to autumn sown wheat, but the crop will move through the growth stages a lot quicker.
Autumn sown, and spring sown barley have a similar programme to wheat but using the relevant herbicides, insecticides, fungicides and PGRs suitable for barley.
For full programmes please talk to your Ruralco Representative.
Ryegrass
Most ryegrass crops have been closed. Closing date depends on the varieties flowering date. This takes place from late September onwards. At GS 32 a PGR is sprayed on to stop lodging. Once the ear starts emerging a fungicide programme is started. Late weeds also can be controlled at this time.
For a full programme please talk to your Ruralco Representative.
White Clover
Now that it is up and growing it is a matter of controlling weeds. What is used depends on the weed spectrum
For further information please contact your Ruralco Representative.
Fodder Beet
Most fodderbeet crops have been sown and a preemergence spray has been applied. Once the fodder beet has emerged an early post emergence spray is applied, as well as another insecticide. This season a new insecticide has been registered for Fodder beet from Bayer called Sivanto Prime. This can be used from the Cotyledon stage for control of Nysius, Springtails and Aphids and is IPM friendly.
Towards the end of the month the 2nd post emergence herbicide spray will be applied as well as herbicide sprays to control grass weeds and thistles. To control grass weeds in fodder beet we have 2 main products. Sequence from Nufarm has a registration for fodder beet with a withholding period of 63 days before grazing. Gallant is now registered for use in fodder beet crops as well but remember it has a withholding period before grazing of 14 weeks (98 days) plus other conditions. Make sure you read the label before applying. Gallant can also be used to control storksbill. Regular insecticides sprays are needed to control aphids. A fungicide can also be applied. These should be applied at first sign of disease with a maximum of 2 sprays per season. Remember to check the withholding period of any products used when starting to graze your crops with fungicides such as Escolta having a 42-day withholding period before grazing or Custodia having a 28-day withholding period.
For further information on growing fodder beet please contact your Ruralco Representative.
Maize
Maize has mostly all been planted. With no Emblem Flo being available this season, weed control needs to start at the pre-emergence stage using Acetochlor and Atrazine. Once the maize has emerged and any weeds are seen we can decide what other post emerge chemicals need to be used.
For further information on growing maize please contact your Ruralco Representative.
Forage Brassicas
After planting, a pre-emergence spray is normally applied for weed control. Regular insecticide sprays are also needed to control insect pests. Normally a post emergence weed spray is required. Be careful what is used at this stage as what chemical used here can affect what can be grown next year. Corteva have a product for controlling weeds in Fodder Brassicas called Milestone. This covers a good range of weeds. They also have Korvetto. This product has short plant-back periods. excellent crop safety and kills a good range of weeds but needs to be applied when weeds are small.
Forage Brassicas are an ideal crop to use IPM (Integrated Pest Management) in. IPM refers to the use of cultural and biological controls as well as selective chemical insecticides that can be used to effectively control pests in crops. Selective insecticides include Transform, Ultima, Lustre, Pirimor, Sparta, Syntium, Twinguard, and Exirel. These products only target the pests leaving the beneficial insects such as hover flies, lacewings, ladybirds and others to go about their business of controlling the pests.
Monitoring store Grain
Monitoring grain during storage is a valuable tool in maintaining quality. This becomes more important the longer the grain remains in storage because deterioration in seed quality early in storage is slower and insects are sparse and not easily noticed. Temperature and seed moisture content are important indicators of grain quality that influence insect and mould activity. Once grain is in storage, monitoring for insects and mould once a month will give early notice of any problems occurring and action can then be taken to control these problems.